Social Factors That Affect Good Health
Senior 1 · Biology
Social Factors That Affect Good Health
Lesson 3 of 5
25 min
Mutesi has a painful ear infection. The nurse at the health centre gives her a medicine and tells her exactly how many tablets to take, and for how long. In the same week, a boy in her neighbourhood swallows tablets he found in a relative's cupboard "to feel relaxed", and ends up at the health centre too.
Both took a drug. One drug helped; the other harmed. So is the drug the problem, or the way it was used? In biology, the word drug is not good or bad in itself: what matters is why, how much, and under whose advice it is taken.
Definition
Drug: any chemical substance, other than food and water, that changes the way the body or mind works when it is taken in. Examples: an antibiotic, paracetamol, caffeine, nicotine, alcohol, cannabis.
Medicine (medical drug): a drug used to prevent, diagnose or treat disease, at a safe dose, usually on the advice of a health worker.
Psychoactive drug: a drug that acts on the brain and changes mood, perception, thinking or behaviour. Examples: alcohol, nicotine, cannabis, caffeine.
Definition
Prescription medicine: a medicine that may be supplied only on the written order (prescription) of a qualified health worker. Over-the-counter medicine: one that a pharmacy may sell without a prescription.
Drug misuse: using a medicine in a way other than intended, for example the wrong dose, someone else's medicine, or stopping early. Drug abuse: using a drug for non-medical reasons, usually to change one's mood, in a way that harms health or breaks the law. (The WHO now prefers the term harmful use; REB's syllabus uses drug abuse.)
| Medical use | Non-medical use (misuse or abuse) | |
|---|---|---|
| Purpose | prevent, diagnose or treat a disease | to change mood, to "fit in", from curiosity, or to escape stress |
| Who decides | a qualified health worker | the user, or someone pressuring the user |
| Dose | measured, and written on the label | unknown, often increasing over time |
| Quality | registered, tested medicines | often illegal, of unknown strength, sometimes mixed with poisons |
| Example | a full course of an antibiotic for a bacterial infection | taking a relative's sleeping tablets; smoking cannabis |
Figure 1: Whatever the route, a drug acts only after the blood carries it to its target, often the brain.
Psychoactive drugs change the way nerve cells in the brain pass messages to each other. They are often grouped by their main effect on the nervous system:
| Group | Main effect | Examples |
|---|---|---|
| Stimulants | speed up the nervous system: alertness, faster heart rate | caffeine (coffee, tea), nicotine (tobacco), khat, cocaine |
| Depressants | slow down the nervous system: relaxation, slower reactions, sleepiness | alcohol, sleeping tablets, heroin |
| Hallucinogens | change perception: seeing or hearing things differently | LSD, some mushrooms; cannabis in high doses |
| Painkillers (analgesics) | reduce pain | paracetamol (medical use), morphine (only under medical control) |
With repeated use, the body adapts. A user may develop tolerance, then dependence, and suffer withdrawal symptoms when stopping.
Definition
Tolerance: a state in which more and more of a drug is needed to produce the same effect.
Dependence (addiction): a strong need to keep taking a drug, so that the person finds it very hard to control or stop their use even when it harms them.
Withdrawal symptoms: unpleasant effects, such as shaking, sweating, sleeplessness or anxiety, that appear when a dependent person stops taking the drug.
Worked example 1: medical or not?
Classify each case as medical use, misuse or abuse, and give the reason.
Method: ask (1) was there a medical reason? (2) was it prescribed or advised for this person? (3) was it taken exactly as directed?
Worked example 2: reading a medicine label
A label on a prescribed medicine reads: "Take 1 tablet every 8 hours. Do not take more than 3 tablets in 24 hours. Do not drink alcohol while taking this medicine."
Answer: 6 a.m., 2 p.m. and 10 p.m.; never more than 3 tablets in 24 hours; no alcohol.
In Rwanda, a Ministerial Order of 2019 lists the drugs that the law treats as narcotic drugs, in three categories. The Order also states that narcotic and psychotropic drugs may be used only on the written prescription of a certified health practitioner.
| Category | Examples named in the Order |
|---|---|
| Very severe narcotic drugs | cocaine, heroin, cannabis, opium |
| Severe narcotic drugs | khat, shisha, Datura stramonium, electronic cigarettes |
| Simple narcotic drugs | alcoholic drinks produced without complying with standards and the law; chemicals used as drugs for a purpose they were not made for |
You will meet the penalties, and the laws that protect children, in the lesson on alcohol, tobacco and cannabis.
How do drugs affect the brain? (TED-Ed, 5 min). Watch for the routes into the blood shown in Figure 1, and for how drugs interfere with the chemical messages between nerve cells.
In small groups, list the reasons why a young person might first try a psychoactive drug (for example curiosity, pressure from others, stress, or wanting to seem older). For each reason, suggest one healthier way to meet the same need. Discuss ideas in general; you do not need to share anything personal.
Warning
Never share or keep medicines. A prescription is made for one person, one illness and one dose. "Natural" or "herbal" does not mean safe, and a drug bought from a street seller has an unknown strength and may contain poisons.
Tip
Memory hook: the three Ws. Before taking any drug ask: Why am I taking it? Who advised it? What dose does the label say?
Practice: drugs and drug abuse
Key points
Sources and credits
Written by Ganzaa: the lesson text, Figure 1, the tables, the worked examples, the discussion and the practice questions.
