School Science Lessons
Drugs
2012-01-28 SP
Please send comments to: J.Elfick@uq.edu.au
Table of contents
WARNING! Before planning to teach any of the topics or content below, get permission from the head of your school science department OR the principal of your school.
Some of the information in this page was originally published by the Australian Drug Foundation, 2006.
11.11.0 Drug abuse
11.12.0 Tranquillizers
11.11.0 Drug abuse, (tranquillizers)
11.11.01 Abuse of volatile substances, inhalants
11.11.3 Alcohol abuse, ethanol
11.11.4 Amphetamines
11.11.5 Antihistamines
11.11.6 Aspirin and analgesics
11.11.7 Barbiturates
19.5.0 Caffeine
11.11.10 Cannabis
11.11.1 Chroming, "huffing"
11.11.11 Cocaine and crack cocaine
11.11.13 Designer drugs
11.11.0a Drugs terminology and classifications
11.11.12 "Ecstasy"
11.11.9 Hallucinogenic drugs, hallucinogens
11.11.15 Heroin
11.11.4.2 "Ice"
11.11.9.1 LSD
11.12.6 Misuse of prescription drugs
11.11.14 Morphine and derivatives
11.11.16 Nicotine, tobacco smoking and chewing
11.11.2 Petrol-sniffing
11.11.1b Reasons for trying drugs
11.11.5.1 Skin-prick tests for allergy
11.11.4.1 "Speed" and "base"
11.12.0 Tranquillizers
11.12.0 Tranquillizers
11.12.4 Drug interactions
11.12.5 Drug tolerance
11.12.2.1 GHB
11.12.2.2 Ketamine
11.12.1 Tranquillizers 1, major tranquillizers, phenothiazines, chlorchromazine (Largactil), promethazine (Phenergan), depressants
11.12.2 Tranquillizers 2, minor tranquillizers, benzodiapines, diazepam (Valium), oxazepam (Seraz, Serenid), nitrazepam (Mogadon), flunitrazepam (Roh)
11.12.3 Tranquillizers 3, minor tranquillizers, dibenzazepines, imipramine (Tofranil), desipramine (Pertofran), amitriptyline (Tryptanol), nortriptyline (Allegron)
11.11.0a Drugs terminology and classifications
11.11.1a Addiction
11.11.2a Classification of drugs
11.11.3a Cocaine and amphetamines
11.11.4a Detoxification
11.11.5a Drug dependence
11.11.6a Drugs and medications
11.11.7a Harm reduction
11.11.8a Mode of action of drugs
11.11.9a Therapeutic index
11.11.10a Types of drug use
11.11.1a Addiction
This term refers to people with a pattern of behaviour that make their lives become unmanageable, e.g. addiction to alcohol and drugs. Addiction involves a strong desire to engage in the particular behaviour, impaired capacity to control the behaviour, distress when the behaviour is prevented, and persistence with the behaviour despite evidence that it leads to problems. People with an addiction need to face the reality of the situation and to have some positive experiences to regain self-esteem and hope. They must attempt to find a new set of values or personal orientation to achieve successful control and cure.
11.11.2a Classification of drugs
Drugs can be classified based on the effects they have on the central nervous system. Some drugs can fall into more than one of these categories. For example, cannabis can be classed as a depressant, but in sufficient doses it can also act as a hallucinogen.
1. Analgesics, "painkillers" relieve pain at the source of the pain or along the central nervous system. These drugs include opiates, e.g. morphine, codeine, aspirin, ibuprofen, "Tylenol".
2. Anticonvulsants inhibit the spread of cortical stimulation, e.g. "Dilantin", hypnotic sedatives.
3. Hallucinogens, psychotropics, "mood changers" can alter perceptions and sense of time and space. These drugs include ketamine, LSD, magic mushrooms, cannabis, antipsychotics e.g. chlorpromazine, cocaine, antidepressants, e.g. imipramine, mood stabilizers, e.g. lithium, anti-anxiety drugs, e.g. "Valium", "Librium", alcohol, kava, St. John's wort.
4. Sedatives, hypnotics ("downers") depressants, suppress or decrease the activity of the central nervous system. These drugs may increase sleep, lessen anxiety, create calm. These drugs include alcohol, cannabis, sedatives, tranquillizers, barbiturates, e.g. phenobarbital, "Nembutal", amytal, benzodiazepines, e.g. "Librium", "Valium", sleeping pills and opioid drugs, e.g. heroin, methadone, "Benadryl".
5. Stimulants increase the activity of the central nervous system. They are addictive and may affect the cardiovascular system. These drugs include amphetamines, ecstasy, cocaine, nicotine, xanthines, e.g. caffeine, "diet pills", "Sudafed", "Actifed".
11.11.3a Cocaine and amphetamines
These drugs belong to a group of drugs that mimic the natural substances that stimulate the central nervous system (CNS). They cause an elevation of mood, a sense of increased strength and mental capacity, and less need for sleep or food. The people living high in the Andes chewed the leaves of the coca bush for generations for just this purpose. The cocaine is converted from the hydrochloride salt to the free base with alkali and extraction with organic solvents. Absorption from the lungs is then increased dramatically. The drug is highly addictive.
11.11.4a Detoxification
This term refers to the means by which the drug-dependent person may withdraw from the effects of that drug in a supervised way.
11.11.5a Drug dependence
This term describes the pattern of behaviour shown by drug dependent users and the physical changes experienced by them.
Drug-related disabilities
This term includes harm suffered through changed behaviour because of the intoxicating effects of the drug, dependent use of the drug, poor nutrition and poor hygiene, impurities or contaminants in the drug used and harm from diseases contracted because of lack of health care, e.g. HIV/AIDS.
11.11.6a Drugs and medications
To avoid confusion between "medication" and widely prohibited "drugs" such as cocaine, heroin and other substances, distinguishing it between these two words is advisable. Drugs administered by medical prescription should be called "medications". Drugs can be classified as analgesics (pain deadening) sedatives and tranquillizers (reduce anxiety) stimulants, anti-depressants, hallucinogens. A drug is any chemical that changes the mental state and that may be used repeatedly for that effect by a person. Drugs may adversely affect the health of the individual and the social surroundings. "Drug" refers to alcohol, tobacco, psychoactive drugs (amphetamines, ecstasy) illicit drugs (heroin, cannabis, cocaine C17H21ON4) volatile substances (petrol, some fluorocarbons) and anabolic steroids.
11.11.7a Harm reduction
This term refers to the new approach being taken to all drug-related problems. The aim of any intervention is not so much stopping drug use but focussing on the reduction of specific drug-related harm. Harm reduction for injecting drug users primarily aims to help them to avoid the negative health consequences of drug injection and improve their health and social status. To this end, harm reduction approaches recognize that for many drug users, total abstinence from psychoactive substances is not a feasible option in the short term, and aim to help drug users reduce their injection frequency and increase injection safety. The following are components that typically have a significant potential to reduce individual risk behaviours associated with drug injection:
1. Needle-syringe programmes (NSP) aim to ensure that those drug users who continue injecting have access to clean injection paraphernalia, including needles and syringes, filters, cookers, drug containers and mixing water.
2. Drug substitution therapy (DST) involves the medically supervised treatment of individuals with opiate dependency based on the prescription of opiate agonists such as methadone.
3. HIV-related treatment and care primarily aims to help drug users living with HIV and AIDS cope with their infection.
11.11.8a Mode of action of drugs
The effect of drugs is strongly influenced by the personal and social environment. Traditional drugs used in traditional ways often cause few problems. Opium and cocaine are good examples. In a different legal and social climate their effects can be disastrous. Opiates reduce pain, aggression and sexual drive. (Opium from Greek: opion, poppy juice.)
11.11.9a Therapeutic index
This term refers to the ratio of the toxic dose to the effective dose. The larger the index the safer the use of the drug
11.11.10a Types of drug use
1. Social and recreational use for enhancing social interaction or the enjoyment of some leisure activity.
2. Symptomatic use for reducing unpleasant sensations or experiences or to avoid challenging situations or responsibilities.
3. Dependent use so that other responsibilities are neglected and harm may result. Such dependent use becomes habitual. Abstinence may be associated with the onset of withdrawal symptoms and the discomfort of withdrawal will become a motivator for renewed drug use.
11.11.1b Reasons students may give for trying drugs and what the teacher can say in reply
1. “Someone had some and I thought I'd try it."
Dress your concern and question their decision. Ask whether it was what they expected talk about the risks of further use. Try and find out if they felt pressured. This may lead to better ways for them to handle a similar situation in the future. Consider using examples of times when you have had to deal with similar situations.
2. “I always wanted to try that stuff."
As what made that particular drug appealing, and what they expected to get from it. Questions such as "What did you think it would be like?" and "Why that drug?" may be worthwhile. You may be able to discuss whether they have tried other drugs and if so, why. Say that you're concerned with their behaviour and try to establish some ground rules.
3. "All my friends were doing it so I thought . . . why not?"
Make your feelings about drug use clear and explain why you don't want them to use drugs. Ask if they felt it was safe because their friends were using it. Ask why they thought their friends used it and whether they were aware of the risks. Discuss the dangers of experimenting with drugs. Discussing the importance of being able to make their own responsible decisions may be useful instead of following the crowd.
4. “It made me feel really good."
Try exploring the main reason the young person took the drug. Find out how they have been feeling. This is a good time to offer help and to find out if you can do anything for them or if they want to talk about another issue. Talk about less risky way of feeling good.
11. "All my problems from school, home and life just went away.”
This statement is a chance to really confront other issues. You can express your concern about students who use drugs for coping. Let them know that if there are problems, you would like to talk about them. Ask what can be done to make things better. Discuss whether the problems returned after the effects of the drug wore off. Express your feelings about the dangers of using drugs to deal with problems. Make it clear that you want to work together to find a better way of solving their problems.
6. “It gave me more confidence."
Let them know that this is of concern to you and explain that they don't need drugs to feel good about themselves. Share your own experiences where you also found it difficult in social situations and explain ways that helped you gain more confidence. These can be both positive and negative experiences. By acknowledging your own behaviour, you will increase your credibility with the young person. Consider ways in which you can help to improve the student's confidence and self-esteem.
11.11.01 Abuse of volatile substances, inhalants
Product: Inhalants can include general household and office products, e.g. solvents, aerosols, glue, petrol.
Street name:
Nitrous oxide: laughing gas, whippits, nitrous.
Amyl nitrate: snappers, poppers, pearlers, rushamines.
Butyl nitrate: locker room, bolt, bullet, rush, climax, red gold.
Symptoms: Slurred speech, impaired co-ordination, nausea, vomiting, slowed breathing, euphoria.
Potential problems: Brain damage, paralysis, pains in the chest, muscles, joints, heart trouble, severe depression, fatigue, loss of appetite, bronchial spasms, sores on nose or mouth, nosebleeds, diarrhoea, bizarre or reckless behaviour, suffocation, sudden death.
A volatile substance is not a drug but misuse of them cause similar problems to misuse of drugs A volatile substance is a compound that gives off a vapour or fumes at room temperature. The recreational sniffing of gases and solvents has become relatively common, particularly among adolescents in Australia, with the mean age of solvent abusers being 12 to 15 years. Volatile substances include petroleum fuels, propellants from aerosol products, chlorinated hydrocarbons, glue, nail polish remover, antifreeze, paint thinners and anaesthetic products. All of these substances are fat soluble and are stored in the fat deposits within the body, particularly in the brain. This leads to a prolonged effect on the level of consciousness even hours after the inhalation has stopped. This is an extremely dangerous practice and sudden death may occur even during the first usage. Substances are generally placed into a plastic bag, or another vessel, and placed directly over the nose and mouth and inhaled deeply. The effect of substances inhaled in this manner produces alterations in the level of consciousness including a pleasurable feeling of intoxication and visual hallucinations. The most important problem of volatile solvent use is the occurrence of potentially fatal cardiac arrhythmia because of intoxication. Respiratory depression can also occur. Although there are doubts about physical addiction, psychological dependence is common. Behavioural indicators of use include persistent truancy from school, unruly behaviour, lack of attention in the classroom, frequent use of handkerchiefs, continual sniffing or sucking of shirt sleeves or jacket sleeves, change in sleep pattern, truculent moody behaviour, difficult communication with parents or teachers. The effects of a single use, while potentially very dangerous, usually wear off after a few hours and the cardiovascular symptoms predominate. Other symptoms include chronic or frequent cough, tinnitus, chest pain or angina, nosebleeds, extreme tiredness or weakness, increased nasal secretions, red, watery eyes, a dreamlike state with hallucinations, depression and / or anxiety. The effects of inhalation are immediate, lasting from 5 to 45 minutes after cessation of sniffing. While initial effects may fade after several minutes, depending on the method of inhalation, effects may be felt for several hours. For most users effects will pass within an hour of ceasing inhalation of the volatile substance. Chronic users may experience withdrawal symptoms similar to those experienced from a general anaesthetic. Hangover effects may persist for several days, and may be characterized by tremor, headache, nausea, vomiting and delirium. Most users of volatile substances are young adolescents, 12 to 15 years. In some groups there is predominantly chronic or dependent use, e.g. among Aboriginal youths, i.e. between the ages of 15 and 24 years. Sometimes, the use of computer games to stimulate recreational activity has been found useful in those young people who are seeking and achieving abstinence from solvents. A video role play approach has been helpful by using the role play in discussions involving resolution of crisis and difficulties in relationships with parents or other members of the family. These films can be used in the education of other abusers of volatile substances.
11.11.1 Chroming, "huffing"
"Chroming" refers to sniffing aerosol spray paint can fumes usually from plastic bags or drink bottles. The term comes from the lead chromate in silver gold and bronze coloured paint that have a high concentration of toxic compounds that can get you "high". Other inhalants used for chroming are typewriter correction fluid, "White Out" or "Liquid Paper" thinner and model aircraft cement. The drunken dizzy feeling induced is often accompanied by excitability, euphoria, decreased inhibitions, delusions of grandeur, and reckless behaviour. Long-term use can lead to permanent damage to major organs, depression and anxiety disorders, and dependence. Some addicts become suffocated by the plastic bags used. Medical evidence suggests damage done to hyopcampal stem cells in the brain causes memory impairment and to cerebral cortex cells causes personality changes, hallucinations and memory impairment. However, one report suggests that it very difficult to find a link between chroming and hallucinations.
11.11.2 Petrol-sniffing
Petrol sniffing is a common practice among the youth of poor Aboriginal settlements in the Australian outback. Besides damage because of inhalation of the volatile components of petrol, lead poisoning may occur even from "unleaded petrol" because it still contains a small amount of lead that may be accumulated in body fat by persistent sniffing. However, the petroleum company BP has produced a new form of gasoline called "Opal" that does not contain lead and contains only a very low level of the aromatic hydrocarbons that give petrol sniffers their "high". The substitution of Opal for normal petrol has been a very effective way to stop petrol-sniffing.
11.11.3 Alcohol abuse
No specific level or pattern of drinking alcohol should be considered safe. It has been agreed from available evidence that a range of drinking that most people would consider low risk and drinking that is considered hazardous, dangerous or dysfunctional, can be defined.
Low risk drinking
Female: Never more than two standard drinks in a day (except for pregnancy)
Male: Never more than four standard drinks in a day
(1 standard drink = 10 grams of alcohol)
Hazardous drinking refers to drinking that raises the blood alcohol level (BAL) above 50 mg alcohol/100 mL blood (0.05%)
Clinical signs and symptoms of possible hazardous alcohol use include: morning nausea and vomiting, dyspepsia, recurrent diarrhoea, hypertension, palpitations, anxiety, hand tremor, financial difficulties, depression in spouse or family members. Dysfunctional drinking is drinking that has already led to psychological damage or to impairment of social functioning, including disturbance of marital or family relationships, drink driving or other convictions, impaired job efficiency.
National health and medical research council recommendations: In 1992 the National Health and Medical Research Council published a series of recommendations about responsible drinking behaviour.
That the idea of a standard drink, or unit, containing 8-10 grams of absolute alcohol be adopted for clinical and educational purposes. That the following guidelines be promoted as consistent with responsible drinking: that the consumption of alcohol by men should not exceed 4 units or 40 grams of absolute alcohol per day on a regular basis, that the consumption of alcohol by women should not exceed 2 units per day or 14 units per week on a regular basis that 2-4 units per day or 14-28 units per week be considered hazardous and that more than 4 units per day or 28 per week be considered harmful. Caucasians oxidize ethanol slowly to acetaldehyde then further oxidation to acetic acid occurs. So they tend to become drunk because the alcohol stays unchanged in the body. Northern Chinese and Japanese may oxidize the alcohol more quickly causing red cheeks and unpleasant sensations from the sudden increase of acetaldehyde in he blood. Eventually the alcohol is metabolized by the slow acting alcohol dehydrogenase enzyme in the liver assisted by the extra-enzyme cytochrome mono-oxygenase in heavy drinkers. Alcohol dehydrogenase converts alcohol in the liver to acetaldehyde. Fast acetylators can be embarrassed by the flushing that occurs after drinking alcohol because of the sudden release of acetaldehyde. The further oxidation to acetic acid occurs at the same rate in both fast and slow acetylators.
11.11.4 Amphetamines
Amphetamine, epinephrine (adrenaline) amphetamine-type stimulants, ecstasy, "speed", "base", ice
Amphetamine-type stimulants are synthetic drugs which means they are made by combining various chemical ingredients rather than occurring naturally
Amphetamines are a family of drugs that include methamphetamine. These drugs are similar in their chemical make-up and affect the messages going to the body's central nervous system. Currently, methamphetamines are more common in Australia than other amphetamines. These types of drugs are sold in different forms such as powder, paste, liquid, pills and crystals. The potency of these forms varies, with the most potent being the crystalline form, typically called Ice or Crystal Meth.
Ecstasy, MDMA, 3, 4-methylenedioxymethamphetamine, is also an amphetamine-type stimulant and mild psychedelic because it has a chemical structure that is similar to amphetamines. The effects of ecstasy are different from amphetamines and can bring on some effects more typically found in hallucinogenic substances. Ecstasy pills contain about 40 mg of MDMA but powder is also available. Research show that consistent users of this drug experience slight memory difficulties and mild depression but some people have more severe symptoms. The short-term effects for a small fraction of users my include severe overheating or water intoxication leading to death. The drug may cause long-term damage to the serotonin system.
Amphetamine / methamphetamine
Speed, base and ice are currently the most common street names for these types of drugs. They share the same symptoms and potential consequences but can differ in severity.
Designer drugs
1. The psychoactive compounds, phenylethylamines (mescaline analogues), e.g. catecholamines, amphetamine, methamphetamine,
3, 4-methylenedioxyamphetamine (MDA, ecstasy) and 3, 4-methylenedioxymethamphetamine (MDMA)
Amphetamine overdose may cause tachycardia, hypertension, hyperthermia, diaphoresis, mydriasis, agitation, muscle rigidity, and hyper-reflexia. Death usually results from arrhythmias, hyperthermia or intracerebral haemorrhage.
2. Synthetic opioid derivatives, derivatives of fentanyl (e.g. alpha-methylfentanyl, 3-methylfentanyl) or pethidine (meperidine)
3. Arylhexylamines, e.g. phencyclidine (PCP) a derivative of the anaesthetic ketamine. The halucinogenic drug phencyclidine hydrochloride is known as angel dust.
11.11.4.1 "Speed" and "base"
Product: Methamphetamine hydrochloride, amphetamine sulfate (grey, dirty-white, pinkish powder, paste, liquid and pills).
Street name: Speed, whiz, go-ee, zip, oxblood, dexy's midnight runners, phets, meth, base, glass, uppers, whizz, billy, sulph. base, paste, pure, gas, amphets.
Symptoms: Common responses to intoxication include euphoria, increased blood pressure and pulse rates, increased and irregular breathing and heartbeat, insomnia, loss of appetite and dilated pupils, confidence, increased energy, talkativeness and excitability
These drugs can cause anxiety, restlessness, sweating, overheating, blurred vision, nausea and diarrhoea, jaw clenching and / or teeth grinding.
Potential problems: Sleep problems, dental problems (e.g. cracked teeth through grinding) weight loss, stroke or heart problems, high risk of dependence. Injecting the drug is also associated with a risk of contracting blood-borne viruses, like hepatitis C and HIV
Problems with attention and memory, paranoia and paranoid delusions, anxiety, panic attacks, hallucinations, depression, mood swings, aggression, violence, social and financial problems, compulsive repetition of actions, family arguments and conflict, the risk of family breakdown and losing friends.
Speed is the street name for amphetamine and a range of amphetamines. Amphetamine is similar to norepinephrine, the "fright hormone" that causes the response to sudden stress or excitement. The pharmaceutical classes of amphetamine include laevo or dl-amphetamine ("Benzedrine") dextroamphetamine ("Dexedrine") and methylamphetamine ("Methedrine") called "crystal meth". Speed is usually amphetamine sulfate that contains equal amounts of laevo-amphetamine and dextroamphetamine. A "speedbomb" is speed wrapped in cigarette paper to form a pill which when swallowed may cause stomach pains, inflammation and ulcers. Speed may be "cut" (diluted) with milk powder, paracetamol and other white powders but the pink-grey "base speed" is usually more pure. People take speed because it gives them a feeling of awareness and excitement, they get "high". In night clubs people take it to help them to dance all night. Formerly, amphetamines were prescribed by doctors for overweight patients because amphetamines reduce appetite. Injected speed produces and quicker and longer "high" then a slow "comedown".
11.11.4.2 Ice
Ice generally looks like colourless crystals or crystalline powder. The difference between Ice and Speed / Base is the way it is made. The chemicals are the same but Ice is a highly potent drug that increases the severity of the potential consequences.
Product: Crystal methamphetamine hydrochloride
Street name: Ice, meth, crystal, crystal meth, sabu, batu, d-meth, tina, glass.
Other potential problems: In the short-term, Ice can produce increased heart rate, hypertension, irregular body temperature, increase breathing rates, constrict blood vessels, and cause heart problems.
Longer-term users of the drug can typically appear older than their age and may have damaged teeth, skin lesions, and greater risk of strike, decreased lung function and poorer cognitive function.
Ice users are at risk of experiencing a drug-induced psychosis, they can become paranoid and hallucinate. A person can become increasingly aggressive and have violent behaviour possibly requiring chemical and physical restraint or police intervention.
There is a high risk of addiction, including through smoking. Damage can occur to lungs through smoking Ice and to the lining of the nose through snorting. If injected it can lead to scarring, abscesses and vein damage.
The Queensland Department of Health reports that ingesting ice can cause addiction, emergency psychiatric care, violence, aggression, hallucinations, paranoia, anxiety, panic, depression, bizarre beliefs, and compulsive behaviour.
11.11.5 Antihistamines
Histamine, dexchlorpheniramine (Polaramine), allergy
Many people are allergic to pollen, stings, and dust. An allergen is a substance that initiates the allergic response. It is usually a protein but is sometimes a polysaccharide. For a person with pollen allergy, a pollen grain enters the nose and clings to the mucous membrane. The nasal secretions acting on the pollen grain release the grain's allergens and other soluble components, which penetrate the outer layer of the mucous membrane. By a series of events that are not well understood, the allergen forms a complex with an antibody of a type that is present in unusually high concentrations in allergic persons. The complex is responsible for the release of the allergy mediators, one of the most potent being histamine. Histamine is formed by the breakdown of the amino acid histidine. It accounts for many symptoms of hay fever and other allergies.
Antihistamines are most widely used for treating allergies, and there are more than 50 types available. Like histamine, many contain an ethylamine group, -CH2CH2N =. These drugs compete with histamine for the receptor sites normally occupied by it on cells and thus prevent it from causing allergic reactions. An example of a well known antihistamine is Polaramine. Some tricyclic antidepressants have antihistamine effects as well, because they also contain the ethylamine group.
11.11.5.1 Skin-prick tests for allergy
Put a drop of the solution containing the suspected allergen on the person's forearm. prick the skin under the drop with a sterilized needle. Any itchiness, reddening of the skin or white swelling indicates an allergy to the suspected allergen.
11.11.6 Aspirin and analgesics
Paracetamol, acetaminophen (Panadol, Tylenol)
Both salicylic acid and acetylsalicylic acid (aspirin) can breach the protective barrier in the stomach and cause stomach bleeding. For most people the bleeding produced is trivial however, including children, it can be hundreds of millilitres and require emergency hospitalization. In acid solution aspirin is not ionized and is fat-soluble and can diffuse through the stomach's protective barrier. Once through, it is in a neutral environment where ionizes and then cannot pass back again. The rate of diffusion is enhanced by alcohol even when the contents of the stomach have a low acidity. Such cooperative action may be called synergism. Aspirin has the effect of slowing the release of the prostaglandins that promote inflammation and stimulate pain receptors.
The related methyl salicylate, oil of wintergreen, is used externally to ease the pain from rheumatism and strained muscles. Aspirin kept too long begins to hydrolyse to salicylic acid, which is not well tolerated by the human body. Soluble aspirin is either the sodium or the calcium salt of normal aspirin. These salts immediately form aspirin in the acid stomach as fine crystals and possibly cause less gastric distress. Some analgesics, e.g. Panadol, contain p-acetylaminophenol (4-hydroxyacetanilide, paracetamol) which is comparable to aspirin as a pain reliever but is gentler to the stomach.
11.11.7 Barbiturates
Phenobarbital, amylobarbital, pentobarbital, thiopental
See 16.3.4.0.5a: Barbiturates
Previously, barbiturates were the major ingredients used in sleeping pills and provided adjuncts to anaesthetics. Phenobarbital has distinctive anticonvulsant properties useful in the treatment of epilepsy. Barbiturates are derivatives of barbituric acid that is not pharmacologically active. Replacement of the hydrogen atoms at the fifth carbon position with alkyl or aryl substituents yields drugs with sedative or hypnotic properties. More than 2000 barbiturates have been synthesized but only a few have become widely adopted in medicine. Thiopental is the standard injectable general anaesthetic. The chain length of the substituents at the C-5 position affect the action of a particular barbiturate, e.g. phenyl group or alkyl group for anticonvulsant activity. However, convulsants are produced if the chain is too long or if alkyl groups are placed on the two nitrogen atoms at positions one and three. If thiourea, CH4N2S, is used in place of urea in the synthesizing reaction, thiobarbiturates are obtained, e.g. thiopental. The more fat soluble the barbiturate with non-polar groups, the more rapid the onset of the action. Hypnotic properties may often be increased by increasing fat solubility and may be abolished by introducing polar groups on the side chains. Barbiturates and alcohol are both metabolized in the liver and even when each is at a non-toxic dosage, the combination can be toxic because the alcohol retards the excretion of the barbiturate. When hypnotics are first taken, they may reduce dreaming and interrupt sleep.
Barbiturates classification
Classification of barbiturates according to action time: (The names in parentheses are trade names.)
1. Long-acting: phenobarbital, methylphenobarbital (Prominalb)
2. Intermediate: amylobarbital (Amytal), butobarbital (Sonabarb), butethal (Neonal), hexethal (Ortal), vinbarbital (Delvinal).
3. Short-acting: cyclobarbital (Amnosed), pentobarbital (Nembutal, Petab, Sommital, Penbon, Sodepent, Pentone, Pentobeta), secobarbital (Seconal).
4. Ultrashort-acting: hexobarbital sodium (Evipal), thiamylal sodium (Surital), thiopentonesodium (Pentothal).
5. The thiobarbiturates (Pentothal and Surital) are inactive by mouth and can be administered only by intravenous or rectal routes. They belong to the group of infamous truth drugs. Both tolerance (increasing quantities needed for an effect) and physical dependence occur with high doses. The barbiturates stimulate enzymes in the liver that breakdowns the drug, thus reducing its effect. Although tolerance develops to the sedative effect of the drugs, the lethal dose remains essentially constant. As tolerance increases, therefore, the margin of safety decreases, and accidental poisoning may occur at doses that no longer provide sedation.
6. The therapeutic index is the ratio of the toxic dose to the effective dose. The larger this factor is, the greater the safety in the use of the drug. The therapeutic index is dependent on two types of drug tolerance:
6.1 Pharmokinetic tolerance to changes in the concentration of the drug in the body caused by changes in liver activity
6.2 Pharmodynamic tolerance caused by the receptor (where the drug acts) requiring more drug while the concentration for receptor poisoning may not change.
11.11.9 Hallucinogenic drugs, hallucinogens
Hallucinogenic drugs include mescaline, psilocybin, scopolamine (hyoscine), atropine, LSD, tryptamine, cocaine, THC cannabis
Psilocybin: mushies, blue meanies, magic mushrooms, gold tops, datura, angel's trumpet.
Symptoms: Trance-like state, excitation, euphoria, increased pulse rates, insomnia, hallucinations, paranoia.
Potential problems: visual hallucinations may produce anxiety and fear, confusion and lack of coordination can result in greater risk of injury, self-inflicted injury, violent behaviour, paranoia, depression, anxiety, unpredictable flashbacks.
Hallucinogenic (or related psychotomimetic) drugs derived from various plants and fungi have been used from ancient times. The use of the emetic toadstool Amanita muscaria extends over thousands of years. The Aztec and Mayan cultures used the peyote cactus, from which mescaline is derived. They also used the psilocybe mushroom (or sacred mushroom Teonanacatl, Psilocybe montana) the active principle of which is psilocybin, which is about 30 times as potent as mescaline. From Ipomea (morning glory) the Mexican Indians obtained a substance similar to lysergic acid, and from the plant Datura stramonium (thorn apple) they obtained scopolamine (hyoscine) and atropine from Atropa belladonna, deadly nightshade, belladonna. Other plants used in Central and South America contained cocaine. Tannin in tea contains gallic acid, which can be converted to mescaline. Mescaline is classed as a catecholamine, along with amphetamines, to which it is structurally related.
11.11.9.1 LSD
Product: LSD (lysergic acid dliethylamide) Psilocybin.
Street name: LSD, acid, trips, wedges, windowpane, blotter, microdot
Lysergic acid diethylamide (LSD) is classed as an indoleamine. It is one of the most potent drugs known. Very low doses are capable of causing marked effects in susceptible individuals. Lysergide was discovered while investigating a modified ergotamine as an improved drug for childbirth. Ergot itself is found on many plants, particularly rye. An ergot alkaloid is used to induce uterine contractions. In ergotamine, the diethylamino group is replaced by a peptide. The opiate alkaloid oxycodone, "hillbilly heroin", made from thebaine (paramorphine), C19H21NO3, has unique stimulating properties is usually supplied as oxycodone hydrochloride.
Opioid analgesics based on thebaine (paramorphine), C19H21NO3, include oxycodone ("Oxycontin", "Oxynorm"), oxycodone hydrochloride ("Endone"). These powerful analgesic drugs may be hazardous and harmful
and cause dependence.
11.11.10 Cannabis
Product: Marijuana, hashish, Indian hemp", Cannabis sativa, delta-9-tetrahydrocannabinol (THC)
Street names: Pot, grass, weed, reefer, joint, Mary-Jane, Acapulco Gold, rope, mull, cone, spliff, dope, skunk, bhang, ganja, hash, chronic, yarndi.
Symptoms: Difficulty concentrating, slow reflexes, impaired motor skills, reduced coordination and concentration, apathy, bloodshot or glassy eyes, increased appetite, dryness of the mouth.
Potential problems: Mood swings, memory impairment, weight gain, chronic bronchitis, increased risk of cancer of the lung, mouth, throat and tongue, panic attacks, anxiety, depression, paranoid thinking, decreased motivation, interference with reproductive function, learning difficulties, psychological dependence, suicidal thoughts, risk of psychosis and psychotic symptoms. Cannabis serves as barrier against self-awareness, and may interfere with a young person's development including possible interference with reproductive function.
The most active ingredient in the extract is tetrahydrocannabinol, THC, obtained from the fruiting or flowering tops of the cannabis plant. There are many ingredients in cannabis other than THQ and their long-term effects are unknown. Recent analysis of samples of purchased marihuana indicates an average of 10% tetrahydrocannabinol, about double the average concentration 25 years ago when marihuana was commonly called "grass".
Cannabis is the psychotropic product from the plant Cannabis sativa which is one of mankind's oldest cultivated plants. It is used for its fibrous qualities (hemp) as well as its medicinal properties because of compounds called cannabinoids. The major active ingredient is the cannabinoid "D9 tetrahydrocannabinol" or "THC". It is fat-soluble, so it may remain in the body tissues such as the brain for many days after a single dose.
If cannabis is smoked a "high feeling" is attained much more quickly but if eaten the effects are long lasting. Additive effects are observed with alcohol and other CNS depressants, but no clear interaction has been noted with stimulants. The effects of cannabis include feelings of self-confidence, euphoria, well being and relaxation, altered perception of time and space, heightened perceptions of taste, smell, touch, and hearing, delusions and hallucinations. The main at risk groups are young people with friends who are illicit drug users. Recurrent use may lead to impaired fertility. In males, cannabis use diminishes testosterone production and decreases sperm count. It also results in abnormal shape and chemical composition of the sperm cells. In females, cannabis can affect fertility by disrupting the reproductive cycle through changes to ovulation and menstrual cycles. Another concern is the possibility of foetal damage during pregnancy. In the long-term may result in impotence, loss of normal sex drive and infertility. Heavy cannabis use produces a change in personality and in behaviour that is more dramatically shown by children and adolescents than it is by adults. Some adolescents who use cannabis have been observed to be devoid of the drive and energy normally seen in adolescents. Cannabis is known to be both mutagenic and carcinogenic as well as destructive to lung tissue. Since cannabis smoke is inhaled deeply, held for much longer and contains more tar than tobacco, the adverse effects are greater. As a result, smoking 2-3 cannabis cigarettes may carry the same risk of lung damage as smoking a whole packet of tobacco cigarettes. Use of cannabis may lead to use of "hard" drugs and to drug dependence.
11.11.11 Cocaine and crack cocaine
Product: Cocaine, crack cocaine
Street names
Cocaine: coke, flake, snow, happy dust, Charlie, gold dust, Cecil, C, freebase, toot, white girl, Scotty, white lady.
Crack cocaine: crack, rock, base, sugar block.
Symptoms: Anxiety, agitation, increased pulse rates, enlarged pupils, paranoia, hallucinations, excitability, euphoria, talkativeness.
Potential problems: High risk of addiction, erratic behaviour, hallucinations, cocaine psychosis, eating or sleeping disorders, impaired sexual performance, ongoing respiratory problems, ulceration of the mucous membrane of the nose, collapse of the nasal septum, cardiac arrest, convulsions.
Cocaine is an alkaloid of the coca shrub Erythroxylon coca. It was formerly used as a local anaesthetic for throat surgery. It is prepared as a salt, cocaine hydrochloride. This salt can be inhaled into the nostril or injected by intravenous injection. The cocaine salt can also be converted to free base cocaine that is burned and the smoke inhaled. Most cocaine users begin with intra-nasal administration and later change to injecting use or inhalation of smoke. The free base cocaine, "crack", sold in the streets of American cities is called "crack". In USA, the cheap "crack cocaine" is used by lower socio-economic groups, and expensive pure crystalline cocaine is used by higher socio-economic groups. Cocaine is a highly addictive drug. It produces feelings of increased confidence and exhilaration. High doses cause loss of coordination, dizziness, hallucinations and violent or aggressive behaviour, respiratory paralysis, and death. Unhygienic injections of the drug can cause infections including hepatitis B, hepatitis C and HIV/AIDS. As tolerance to cocaine develops rapidly, social problems develop, e.g. debts, job loss, and impaired productivity. Women have taken to prostitution to support the cost of their cocaine addiction. Users may mix cocaine use with other drugs, e.g. heroin, called "speedball", to enhance effects. Withdrawal from cocaine is a slow and difficult process requiring skilled medical management.
11.11.12 Ecstasy is a derivative of amphetamine and has similar properties. It is used at dance parties and other social venues. With increased use the negative aspects of use tend to increase while the positive effects decrease, so few people have dependence problems with it. The physical effects are teeth grinding, restlessness, dry mouth, increased sweating, hot and cold flushes. nausea and vomiting. Users experience a feeling of improved personal relations, communication and intimacy, and euphoria. However, this may lead to visual hallucinations, anxiety, loss of control and panic. Users may suffer extreme dehydration and even death.
Product: MDMA (Methylenedioxymethamphetamine) (3, 4-methylenedioxy-N-methylamphetamine)
Street name: Adam, E, Ex, E and C, eccy, Ecstasy, eggs, Essence, love drug, MDMA, PMA, XTC
Symptoms: Increased blood pressure and pulse rates, sweating, overheating, jaw clenching, teeth grinding, nausea, anxiety, excitability, tremors, insomnia, enlarged pupils, loss of appetite.
Potential problems: Sleep problems, cracked teeth through grinding, high blood pressure, dehydration, nervousness, hallucinations, memory and attention impairment, decreased emotional control, lethargy, severe depression, possible nerve cell damage, thermal meltdown, death from heart failure.
Amphetamines were once used to treat obesity, mild depression and narcolepsy (a tendency to fall asleep at any time) and certain behavioural disorders in children. Amphetamines are pep pills. Ordinary doses of 10 to 30 mg per day provide a feeling of well being and increased alertness. Amphetamines are structurally similar to the naturally occurring biogenic amines, such as ephedrine, which act as stimulants of the central nervous system, in a similar manner to epinephrine.
Amphetamine and epinephrine are optically active, i.e. two compounds with the same formula with structures mirror images of each other and cannot be superimposed. You cannot place one hand in an identical position on top of the other. However, if you hold them parallel. One hand is as the mirror image of the other. A pair of chemicals related in this way are called left-handed, l, and right-handed, d. Compounds differing only in this way can be biologically very different in their activity. Benzedrine is a 50: 50 mixture (racemic) of the l-amphetamine and d-amphetamine but while the l-form is less active on the central nervous system, the pure d-form, dexedrine, is nearly twice as potent.
Amphetamines and barbiturates were often used in conjunction. Thus amphetamines may be consumed in the morning to alleviate the symptoms of a barbiturate hangover, while the barbiturates may be necessary to counteract the stimulant properties of amphetamines and allow the user to sleep. In case of overdose they were also used as mutual antidotes. The deeply held belief by the public in antidotes is somewhat dangerous, because although two substances may be antidote in one aspect, they can reinforce each other (synergism) in other side effects. The death rate can be very high. The amphetamines also form a family of drugs although the pattern is somewhat difficult to see and tends to overlap other categories of drugs.
In Australia, amphetamines have been used to treat some medical conditions however these drugs are both potentially addictive and quite toxic. The best known members of this group of stimulants are dexamphetamine (e.g. dexedrine), methamphetamine (e.g. methedrine), and the amphetamines (e.g. benzedrine). Amphetamines are simple amines with many effects including cardiovascular and central nervous system stimulant actions which is similar to the naturally occurring hormone adrenaline. They stimulate and excite all areas of the nervous system, including the brain. As they inhibit sleep and fatigue, the main concern is the self-medication of amphetamines by truck drivers, students and businessmen, who use amphetamines to stave off normal fatigue and enable them to work for days with little sleep or food. Young people who frequent night clubs use amphetamines so they can dance all night. Truck drivers use amphetamines so they can drive for long periods without rest and make more trips per week.
The drug has a reputation of facilitating social and sexual interactions:
1. Implications for HIV transmission, i.e. if enhanced sexuality is not accompanied by safer sexual practices.
2. Amphetamines are often used in a casual fashion accompanied by alcohol. The setting is not conducive to the use of clean needles and amphetamine use is an independent risk factor for HIV infection.
Injecting drug users are increasingly emerging as a poly drug-abusing group and as amphetamines are cheaper than heroin on the street more IDUs are including amphetamines in their repertoire of drug use.
Immediate effects at low doses include sensations of euphoria, enhanced self-awareness and self-confidence, increased visual awareness, heightened alertness, increased capacity for concentration, greater energy. Users become hyperactive, talkative, excited, irritable and restless. Effects at high doses include dry mouth, fever, sweating, headache, blurred vision, rapid or slurred speech and collapse. Long-term effects include malnutrition, since amphetamines suppress appetite, and sudden acts of aggression. Multiple drug uses may take depressant drugs such as alcohol and barbiturates in combination to fight the side effects of amphetamine use, such as sleeplessness. Prolonged use may lead to drug dependence.
Methamphetamine (methylamphetamine desoxyephedrine) is highly addictive and is becoming widely used in many countries.
3. Mephedrone, 3, 4-methylenedioxy-N-methylcathinone, 4MMC, MCAT, bubbleluv, drone, miaow, a cheap ecstasy alternative, is an analogue of methcanthionone, MDMA, and may be given an innocent classification as a plant food. It causes euphoria, talkativeness and increased sensitivity. has MDMA-like side effects, e.g. jaw tension, perspiration and depression.
11.11.13 Designer drugs
A new wave of designer has lead to death or permanent brain damage in Europe. Some synthetic drugs, e.g. "Flatliner" (synthetic drug 4MTA) "Golden Eagle", and "DOB" (death of body, "Nexus", "Spectrun", BZP, N-benzylpiperazine) are derivatives of Ecstasy but are known on the rave scene as "Super E" because they are up to 30 times more powerful. "Flatliner" has been blamed for deaths in Britain. "Golden Eagle", an amphetamine-based concoction, is powerfully hallucinogenic, causing "trips" which last up to twenty hours. DOB is 10 to 20 times more potent than amphetamine. BZP tablets, especially those that also contain the hallucinogen TFMPP (1-(3-trifluoromethylphenyl) piperazine) often are sold as MDMA (3, 4-methylenedioxymethamphetamine) are also called ecstasy or are promoted as an alternative to MDMA.
11.11.14 Morphine and derivatives
Codeine, pethidine, heroin, methadone, opioids
Product: Heroin, morphine, codeine, methadone, buprenorphine, pethidine, Dilaudid, Kapanol, MS Contin.
Street name:
Heroin: horse, hammer, H, dope, smack, junk, gear, boy.
Morphine: M, Miss Emma, Mister Blue, morph.
Methadone: done.
Buprenorphine: Bupe.
Symptoms: Lethargy, drowsiness, nausea, constipation, constricted pupils, slowed breathing.
Potential problems: High risk of addiction, mood swings, depression, anxiety, chronic constipation, infection at sites of injection, HIV and hepatitis infections through sharing of needles, non-fatal overdoses, death from overdose.
Morphine was first isolated from the latex of the opium poppy, Papaver somniferum. Another alkaloid, codeine, was isolated from opium. Although codeine has only about one tenth of the potency of morphine, its prolonged use in low doses can cause physical dependence. Morphine was acetylated to produce diacetylmorphine, heroin, which is more addictive than morphine. The first potent analgesic to be prepared that did not depend upon opium for its prime source was pethidine. The molecule can be drawn to show the morphine structure. The first of the synthetic analgesics, based on 3, 3-diphenylpropylamine, was called methadone. The molecule can be drawn to show the morphine structure. The time of onset of physical addiction of the opiates used to be characterized as: heroin 4 to 5 days, morphine 1 week, pethidine 10 days to 2 weeks, methadone 1 month.
11.11.15 Heroin
Heroin is a drug derived from the opiate morphine. Opiates are a group of drugs derived from opium obtained from the poppy flower Papaver somniferum. Heroin is safe and effective analgesic. It should be used only to prevent severe and persistent pain because it causes dependence. Illegal use has produced much suffering and so many people think of it as a "horror drug". The chemical is a white crystalline powder that is soluble in water. The drug is administered by injection or smoking. The onset of action is rapid and the duration of action is 3 to 4 hours. The immediate effect or "rush" after an intravenous (IV) dose is because of the high fat solubility of the drug and thus its rapid entry into the brain. The drug bought by illegal users on the street results is a dose of variable amount diluted by substances of varying quality and safety. Most users inject their dose using solvents for the powder they purchase. These solvents may be contaminated, e.g. lemon juice. Users may be harmed by overdose resulting in a fatal cardiovascular collapse. Most complications of heroin use relate to the injection of contaminated material, or the use of non-sterile injecting equipment that can cause septicaemia and transmission of HIV/AIDS and hepatitis B disease. Methadone, a synthetic opiate, is used to treat heroin users but there are many arguments about using it. It replaces heroin and has a longer life in the body than heroin. Drug users in a methadone maintenance programme receive a single prescribed dose of methadone every day. Methadone maintenance programmes are effective in reducing the frequency of injecting and the incidence of use of contaminated injecting equipment. The Human Immunodeficiency Virus (HIV) can be transmitted through the exchange of HIV-infected body fluids from using HIV-infected injecting equipment. Injection drug users should be warned about the risks of the use of contaminated injecting equipment and taught needle and syringe cleaning techniques or the availability of clean needles and syringes or needle exchange programmes in the area. They should use safer sexual practices and use condoms. New users are at special risk because their drug use is often unplanned and thus they may share needles because they do not possess the necessary equipment.
11.11.16 Nicotine, tobacco smoking and chewing
1. Tobacco comes from the leaf of Nicotiana tabacum. Tobacco smoke contains carbon monoxide, nicotine, tars and poisonous chemicals, e.g. turpentine, acetone, benzene and ammonia. Carbon monoxide is a poisonous gas that is absorbed into the blood stream and temporarily makes the heart work harder. Tars are poisonous chemicals that enter the blood from the lungs and may cause many different cancers. Cancer of the lung, mouth, throat, bladder and kidney are directly caused by some 43 carcinogenic chemicals in tobacco smoke but nicotine itself does not cause cancer.
2. Nicotine is an addictive drug that increases the blood pressure and heart rate. The nicotine content is 0.2% to 5%, i.e. 0.05 to 2.0 mg per cigarette. Nicotine is suspended in particles of tar and is quickly absorbed in the lungs and reaches the brain in about 8 seconds. Like cocaine and amphetamines, nicotine releases dopamine to give good feeling and increase alertness. Nicotine is both a stimulant and a sedative. It releases adrenaline and then glucose and gives a temporary feeling of relaxation and well being. However, this stimulation may be followed by depression and fatigue leading to the person wanting more nicotine. The body of the smoker becomes accustomed to the presence of nicotine and becomes dependent on it. Nicotine is not carcinogenic, does not cause respiratory disease but can delay wound healing, increase insulin resistance and may cause harmful effects on the fetal brain and lungs.
3. Withdrawal from nicotine for 24 hours may result in anger, hostility, aggression and less social cooperation. Stopping access to nicotine abruptly may lead to depressed mood, difficulty in sleeping, irritability, frustration, anger, anxiety, difficulty concentration, decreasing heart rate and in creases appetite and weight gain. Nicotine replacement therapy (NRT) increases sustained abstinence rates. In Australia, nicotine transdermal patches, e.g. 21 mg / 24 hours, are listed on the Pharmaceutical Benefits Scheme as an aid to quitting smoking. Replacing the nicotine in cigarettes with nicotine in skin patches, "Nicabate", "Nicorette", or chewing gum helps people to stop smoking and to quit smoking altogether. Nicotine replacement allows smokers to control their craving for smoking tobacco and avoid withdrawal symptoms. Nicotine can be extracted from tobacco with supercritical solvents. Nicotine chewing gum may include 4 mg or less of nicotine, saccharin / saccharin sodium and flour, e.g. mint. The nicotine is absorbed through the mouth lining so it should be chewed slowly. Nicotine inhalers allow flexible dosage and the familiar hand to mouth action of smoking. An antidepressant tablets to help quit smoking may be available on doctor's prescription., e.g. byprion, C13H18ClNO, "Zyban", and the partial agonist varenicline, C13H13N3, varenicline tartrate "Chantix" and "Champix". There is great reduction in risk in people who stop smoking, even those who stop at 50 or 60 years including less risk of heart attack, high blood pressure, stroke, limb amputation and chronic respiratory problems. Children of smokers are more likely to become smokers. Passive smoking in the home increases the infant's risk of pneumonia and bronchitis. Asthmatic children in a smoking households have more frequent and severe asthma attacks. Male smokers are more likely to be impotent and produce less sperm. Female smokers take longer to conceive and are more likely to miscarry or have premature, stillborn babies or babies dying from cot death.
4. Nicotiana tabacum, derives from the entrepreneur who promoted its sale in France, Jean Nicot. The active ingredient is nicotine. New varieties, better methods of curing the leaf, coupled with technology for mass production, allowed the introduction in the mid nineteenth century of the cigarette. It was cheaper and neater than the cigar, with a smoke so mild it could be inhaled. About 4000 compounds have been found in cigarette smoke. No other drug of dependence causes cancer, and tobacco is the only environmental cause of cancer that is on the increase.
5. Classification for health purposes has concentrated on the levels of nicotine, tar (which contains the potent carcinogens) and carbon monoxide. The carbon monoxide reacts preferentially with the red corpuscles in the blood. On removal of the source of carbon monoxide, the equilibrium with oxygen is gradually restored. The levels of these compounds are determined by using smoking machines. However, smokers do not conform to smoking machines, and manufacturers can design cigarettes to do well on the machines, while dosing smokers at high levels. A common ploy is to include fine holes just up from the filter, which lower the machine reading through dilution of the smoke with air. However, when smoked for real, these holes are covered by the smokers' lips.
6. The nicotine content of tobaccos can vary from 0.2% to 5% and provides from 0.05 to 2.0 mg (1982 average 1.0 mg) per cigarette to a smoking machine. In cigarettes the nicotine is nearly always present in a protonated form in which it is less readily absorbed through the mouth (hence the need to breathe the smoke into the lungs) in contrast to the basic form found in cigars and pipe tobaccos (smoke pH 8.5). The nicotine is suspended on the minute particles of tar and absorption from the lung occurs in seconds. Peak concentrations found in the blood are typically 25 to 50 mg / mL. When heavy smokers are unknowingly given cigarettes with a higher content of nicotine they subconsciously reduce the number smoked and alter their puffing pattern to maintain about their usual level of nicotine. Conversely when given low nicotine cigarettes they increase the number smoked and / or puff more efficiently. If smoking low nicotine cigarettes, the smoker then takes in more tar and more carbon monoxide for the same level of nicotine. The drug is slowly destroyed in the liver and excreted in the urine and faeces. This long delay makes it difficult for law enforcement authorities to decide whether the drug was in use while driving, if this should be an offence.
7. Neurotransmitter release triggered by nicotine
Dopamine --> pleasure, appetite suppression
Noradrenaline --> Arousal, appetite suppression
Acetylcholine --> Arousal, cognitive enhancement
Glutamate --> Learning, memory enhancement
Seratonin --> Mood modulation, appetite suppression
β-Endorphin --> Reduction of anxiety and tension
GABA (γ-aminobutyric acid) --> Reduction of anxiety and tension
11.12.1 Tranquillizers 1, major tranquillizers, phenothiazines, chlorchromazine (Largactil) promethazine (Phenergan) depressants
Product: Sleeping pills, minor tranquillizers
Street name: Benzos, ternazzies, Valium, tranks, sleepers, Serapax, serries, Mandrax, mandies.
Symptoms: Drowsiness, confusion, incoordination, slurred speech, depressed pulse rates, shallow breathing.
Potential problems: Anxiety, depression, restlessness, tremors, insomnia, changes in eyesight, high risks of addiction, suicide.
Tranquillizers
These are drugs that sedate without inducing sleep. The major tranquillizers are used in the treatment of schizophrenia by blocking dopamine receptors in the brain. Many are based on phenothiazine and its derivatives.
1. Aliphatic series
Generic name, Trade name
Chlorpromazine, Trade name: Largactil, Protran, Promacid
Promethazine, Trade name: Phenergan, "Meth-Zin", Progan, Prothazine, Avomine
2. Piperidine series
Thioridazine Trade name: Melleril, Aldazine
Pericyazine, Trade name: Neulactil
3. Piperazine series
Generic name, Trade name
Prochlorperazine, Trade name: Stemetil, Compazine, Anti-Naus
Thiopropazate, Trade name: Dartalan
Fluphenazine, Trade name: Anatensol
Fluphenazine decanoate, Trade name: Modecate
Trifluoperazine, Trade name: Stelazine, Calmazine
4. Thioxanthine tranquillizers are derivatives of phenothiazine that retain the sulfur atom but not the nitrogen.
Generic name, Trade name
Chlorprothizene, Trade name: Taractan
Clopenthixol, Trade name: Sordinol
Flupenthixol, Trade name: Fluanxol
Thiothixene, Trade name: Navane
If the sulfur and the nitrogen atoms of phenothiazine are replaced by (-CH=CH-) and (-CH-) respectively, one of the derivatives is protriptyline. All these compounds are used to relieve the symptoms of schizophrenia and reduce the likelihood of relapse. They affect the brain stem rather than the cortex. Their use has profoundly modified the problems of the mental hospital, but they do carry a high incidence of adverse reactions.
11.12.2 Tranquillizers 2, minor tranquillizers, benzodiapines, diazepam (Valium) oxazepam (Seraz, Serenid) nitrazepam (Mogadon) flunitrazepam (Rohypnol)
The most common of the minor tranquillizers are built up on a benzodiazepine nucleus.
Generic name, Trade name
Oxazepam, Trade name: Serenid
Diazepam, Trade name: Valium
Nitrazepam, Trade name: Mogadon
Chlordiazepoxide, Trade name: Librium (sleeping pill)
Librium was used in the treatment of neuroses, behaviour disturbances, alcoholism and as premedication for anaesthesia. Valium is used to reduce symptoms of anxiety. The differences relate to how fast they metabolize to the fast acting actual drug, nordazepam. Valium loses the 1-methyl group, while Librium hydrolyses the 2-methylamino group to an oxygen. The so-called "date rape" drugs are mainly Rohypnol (flunitrazepam), GHB (gamma hydroxybutyric acid), and Ketamine (ketamine hydrochloride)
11.12.2.1 GHB
Product: Gamma-hydroxybutyrate (GHB)
Street name: Fantasy, grievous bodily harm (GBH) liquid ecstasy, liquid E, G.
Symptoms: Drowsiness, induced sleep, nausea, reduced inhibitions, dizziness, headache, increased sociability, initial euphoria leading to confusion and agitation.
Potential problems: Extreme drowsiness, loss of consciousness, hallucinations, difficulty focussing eyes, vomiting, impaired movement and speech, reduced muscle tone, disorientation, convulsions/seizures, coma, respiratory distress, slowed heart rate, lowered blood pressure, amnesia, death. GHB can be addictive with prolonged use.
11.12.2.2 Ketamine
Product: Ketamine hydrochloride.
Street name: Green, K, super K, special K, Vitamin K.
Symptoms: Altered perception, disorientation, drowsiness, hallucinations, numbness, strange muscle movements, nausea, vomiting.
Potential problems: Accidents from lack of coordination, quick development of tolerance, weight loss and loss of appetite, psychological dependence, psychosis, flashbacks, loss of memory, attention and vision impairment. Ketamine is an anaesthetic. When used with depressant drugs such as alcohol, heroin or tranquillizers, it can be particularly harmful as it has the potential to shut down the body, causing vital organs such as the lungs or heart to stop functioning.
11.12.3 Tranquillizers 3, minor tranquillizers, dibenzazepine, imipramine (Tofranil), desipramine (Pertofran), amitriptyline (Tryptanol), nortriptyline (Allegron)
Tricyclic antidepressants
Depression is a problem that faces many people and the "tricyclics", usually derived from dibenzazepine, form a popular family of antidepressants. These drugs have as many side effects as the tranquillizers. They present a particular problem of overdose abuse
Generic name, Trade name
Imipramine, Trade name: Tofranil, Imiprin, Melipramin, Desipramine, Pertofran
Amitriptyline, Trade name: Tryptanol, Laroxyl, Saroten, Amitrip, Endep
Nortriptyline, Nortriptyline Trade name: Allegron, Nortab
Trimipramine, Trade name: Surmontil A, Doxepin, Sinequan, Quitaxon, Deptran
An interesting series of drugs that are still occasionally used to treat depression are the so-called monoarnine oxidase inhibitors (or MAO inhibitors). The name means that they have the capacity to inhibit an enzyme that is normally responsible for removing certain substances such as norepinephrine (noradrenaline) and serotonin from the body. Currently there is considerable evidence that depressive illnesses are associated with a decrease in the level of these amines in certain parts of the central nervous system, so that by inhibiting their destruction, their level is increased. An example of a biogenic is the amine pheneizine that is similar to amphetamine.
MAO inhibitors
Generic name, Trade name
Iproniazid, Trade name: Marsilid (5% rate of liver damage)
Phenelzine, Trade name: Nardil, Nialamide, Niamid (less effective than a placebo) (deleted from PBS) Isocarboxazid, Marplan, Tranylcypromine, Parnate (strong "cheese" effect, )
Mebanazine, Trade name: Actomol (deleted from PBS)
Patients treated with these drugs have to be warned to avoid eating cheese, red wine, certain beers, piquant foodstuffs such as Marmite and Bovril, and must not take any other medication without consulting their doctor. The reason for this is that these foodstuffs contain tyramine, which is normally broken down in the alimentary canal. When MAO-inhibiting drugs are used, the enzymes that do the breakdown are inhibited, allowing tyramine into the bloodstream. This causes a massive release of norepinephrine, which in turn causes a sudden fluctuation in blood pressure, which produces intense headache and sometimes death.
11.12.4 Drug interactions
Drugs that are taken orally have to be absorbed through the gut, and this can be influenced by other material present. By using suitable coatings a drug can be absorbed either in the acidic stomach or the alkaline duodenum. Once the drug is in the plasma it can become bound to protein and only a small percentage remains free and active. This percentage can be drastically altered by another drug, which kicks the first one off its protein site. Often use is made of this method to boost the efficiency of a drug. Also, a drug can affect the efficiency of an enzyme and hence influence the rate at which a second drug is broken down by that enzyme. The MAO inhibitor drugs and the consequences of eating cheese while they are being taken is a good example.
The way and speed with which drugs are metabolized by the body can also depend on genetic factors, so that comparisons between animals and humans, and between individuals, can be misleading. They also depend on physiological factors, such as age, diet, hormones (including the effects of pregnancy) and disease states, especially if the liver is involved. The old are particularly liable to be treated with several drugs simultaneously and they, in particular, will have impaired metabolism, which will affect the drug's effects on them.
Very often a drug is changed in the body to another compound. Sometimes the new compound is inactive or it may be less active or more active than the original. The original may even be completely inactive and it is the new compound (metabolite) that is the "real" drug. The body can be used as a chemical factory.
The liver has an important role in the metabolism of drugs. Also, many drugs used in treatment of illness have high molecular mass, greater than 400, and as a consequence, are excreted in the bile as well as the urine, so they are frequently subject to bacterial metabolism in the intestines. These products can be reabsorbed and further metabolized by the liver, producing a cycle of absorption, metabolism by the body, excretion, bacterial metabolism, reabsorption and metabolism by the body.
11.12.5 Drug tolerance
Drug users often develop tolerance to the chemical they are using. In the case of the opiates most of the tolerance comes from the adaptation of the cells in the nervous system to the action of the drug. In the case of alcohol, barbiturates and related hypnotics, a group of depressants of the central nervous system (CNS) chronic use causes the capacity of the enzymes that metabolize the drugs to increase, i.e. you can remove the alcohol faster. Occasional alcohol drinkers can metabolize ethanol only with the liver's slow acting enzyme, alcohol dehydrogenase. Chronic drinkers are no more efficient with this enzyme, but they induce a new alcohol destroying enzyme of the P-450, cytochrome mono-oxygenase type in the liver. Such persons can do well on difficult tasks at blood alcohol levels above 0.2 mg / mL. After several weeks of abstinence from drinking alcohol the capacity of this enzyme declines, so that the abstinent alcoholic and normal individual metabolize alcohol at the same low rate. Chronic use often means a higher blood concentration is needed to produce the same effects, i.e. it produces pharmodynamic tolerance. This in turn means that to obtain the same effects, the person will consume more of the drug. However, the fatal dose of the drug does not change. The result is often death by overdose. When the same enzymes are involved, tolerance to one drug can cause cross tolerance to another, e.g. cross tolerance of alcohol with benzodiazepine. So chronic drinkers will deal not only with alcohol more effectively, but also with Valium. If they consume both drugs at the same time, the alcohol will monopolize the enzyme which then is not free to deal with the Valium so the effect of the Valium is enhanced and prolonged. The point at which marked intoxication is caused by drinking alcohol can be monitored by measuring the blood alcohol level or breath level. However, there is a difference between the level which is found to correspond to intoxication "on the way up", i.e. while drinking, compared to "on the way down", i.e. after drinking alcohol has stopped because the effect on behaviour appears to be far less "on the way down" than "on the way up". So motor car drivers caught by a breathalyser test the morning after a heavy drinking may be unaware that their level is still high. Westerners oxidize ethanol only slowly in the first stage to acetaldehyde but Japanese and Chinese may have a gene for an enzyme that oxidizes it faster so a few sips of ethanolic beverage bring a deep red colour to their cheeks and an unpleasant tingling.
11.12.6 Misuse of prescription drugs
Recognizing and dealing with patients who seek drugs for non-medical purposes may be a difficult problem for doctors. Some patients may be “prescription shoppers” or have a chronic non-malignant pain problem. The main drugs they seek include the following:
1. Benzodiazepines, e.g. Alprazolam, “Xanax”, C17H13ClN4, and the benzodiazepine derivative drug Diazepam, ("Valium”), C16H13ClN2O, prescribed for anxiety, insomnia and seizures.
2. Opioids, e.g. Oxycodone, “Oxycodin”, C18N21NO4, derived from thebaine, and Tramadol, “Ultram”, C16H25NO2, prescribed as painkillers.
Misuse of prescription drugs can take the form of injecting oral drugs, selling them on the street, or simply overusing the prescribed amount so that patients run short before the due date and then request extra prescriptions from the doctor. Adequate prescription monitoring mechanisms at the systems level are lacking so doctors must rely on our clinical skills and the patient's behaviour over time to detect problematic prescription drug misuse. Management strategies may include saying “no” to patients, having a treatment plan, and adopting a universal precaution approach toward all patients prescribed drugs of addiction. Among patients with chronic non-malignant pain, requests for increasing opioid doses need careful assessment to explain any non-medical factors.