Presentation on theme: "1 Chapter 35Drugs 35.1Introducing drugs 35.2Anti-acids 35.3Analgesics 35.4Problems with drugs 35.5Hazards of cigarette smoking CONTENTS OF CHAPTER 35 35.6Working."— Presentation transcript:
1 Chapter 35Drugs 35.1Introducing drugs 35.2Anti-acids 35.3Analgesics 35.4Problems with drugs 35.5Hazards of cigarette smoking CONTENTS OF CHAPTER 35 35.6Working towards a smokeless Hong Kong
2 35.1 INTRODUCING DRUGS MEDICINES AND DRUGS Medicines are substances used to cure or prevent diseases. Most medicines consist of one or more drugs. A drug is a substance which changes the state or function of the human body. Alcohol, Milk of Magnesia, aspirin and penicillin are common examples.
3 COMMON TYPES OF DRUGS Drugs fall into a number of types. Anti-acids The word anti-acid means ‘opposite to acid’, often abbreviated as antacid. Anti-acids relieve stomach trouble. They act by neutralizing excess acid in the stomach. 35.1 INTRODUCING DRUGS
4 Figure 35.2 Milk of magnesia is an anti-acid. 35.1 INTRODUCING DRUGS
5 Analgesics Analgesics are painkillers, that is, they relieve pain. 35.1 INTRODUCING DRUGS Figure 35.3 Panadol is an analgesic.
6 35.1 INTRODUCING DRUGS Antibiotics Antibiotics are used to treat bacterial infections. Figure 35.4 Keflex is an antibiotic.
7 Anti-histamines Anti-histamines are used to treat allergy. They are effective in relieving hay fever and allergic rashes. Figure 35.5 Polaramine is an anti-histamine. 35.1 INTRODUCING DRUGS
8 Hypnotics Hypnotics cause sleepiness. Figure 35.6 Barbiturates are hypnotics. 35.1 INTRODUCING DRUGS
9 Tranquillisers Tranquillisers are substances which relieve tension and anxiety. Figure 35.7 Valium is a tranquilliser. 35.1 INTRODUCING DRUGS
10 A35.1 Penicillin is an effective antibiotic. It has saved many lives from bacterial infections since the 1940s. 35.1 INTRODUCING DRUGS
11 35.2 ANTI-ACIDS WHAT ARE ANTI-ACIDS? We can take anti-acids to neutralize the excess acid in the stomach. They usually contain chemicals such as: magnesium hydroxide aluminium hydroxide magnesium carbonate calcium carbonate sodium hydrogencarbonate
13 A35.2 Dyspepsia (or indigestion): difficulty in digesting food Heartburn: a burning feeling just below the heart, caused by indigestion Acid stomach: too much acid (gastric juice) produced in stomach, causing pain Flatulence: Uneasy feeling caused by gas generated in the alimentary canal 35.2 ANTI-ACIDS
14 MAGNESIUM HYDROXIDE/ ALUMINIUM HYDROXIDE AS ACTIVE INGREDIENT Magnesium hydroxide is slightly soluble in water, forming an alkaline suspension. It can thus neutralize the hydrochloric acid in stomach: Mg(OH) 2 (s) + 2HCl(aq) MgCl 2 (aq) + 2H 2 O(l) 35.2 ANTI-ACIDS
15 Figure 35.9 Magnesium hydroxide is the active ingredient of Philips’ Milk of Magnesia. 35.2 ANTI-ACIDS
16 35.2 ANTI-ACIDS Activity 2 Brief guidelines for the project are as follows: A. To find the best buy according to greatest ‘neutralizing power’ per unit dollar B.Comparison of the actions and side-effects on the active ingredients
17 35.2 ANTI-ACIDS C.Other comparisons Size of packet Packaging Appearance of tablet (colour, size, shape etc.) Instructions to users on safe administration of drugs Availability in local market D.Conclusion Based on comparisons in Parts A, B and C, decide, as objectively as possible, which brand of anti-acid tablets is of the best buy. Give your reasoning.
18 CARBONATE / HYDROGENCARBONATE AS ACTIVE INGREDIENT Carbonates or hydrogencarbonates neutralize acid in stomach rapidly. MgCO 3 (s) + 2HCl(aq) MgCl 2 (aq) + CO 2 (g) + H 2 O(l) NaHCO 3 (s) + HCl(aq) NaCl(aq) + CO 2 (g) + H 2 O(l) However, the effect is only short-lasting. 35.2 ANTI-ACIDS
19 Figure 35.10 Magnesium carbonate and sodium hydrogencarbonate are the active ingredients in this brand of anti-acid. 35.2 ANTI-ACIDS
21 35.3 ANALGESICS WHAT ARE ANALGESICS? Analgesics (or painkillers) are drugs to relieve pain. The active ingredient in common analgesics is usually one (or sometimes both) of the following compounds: Aspirin Paracetamol (also called acetaminophen)
22 Figure 35.12 Some brands of analgesics. 35.3 ANALGESICS
23 (a)(b)(c) Figure 35.13 Common analgesics contain aspirin and/or paracetamol (acetaminophen) as the active ingredient. (a)Aspirin and Cortal contain aspirin. (b)Panadol, Tylenol and Saridon contain paracetamol. (c)Exedrin contains both aspirin and paracetamol. 35.3 ANALGESICS
24 THE WONDER DRUG — ASPIRIN Aspirin is the drug which is most widely used as a medicine. It relieves pains (e.g. headache, toothache), and can reduce fever (due to infectious diseases and colds) and inflammation. Aspirin is the common name given to acetylsalicylic acid or sodium acetylsalicylate. 35.3 ANALGESICS
25 Figure 35.17 Beautiful willow trees. Aspirin was first made from willow bark. 35.3 ANALGESICS
26 Figure 35.18 Formulae of the two forms of aspirin. 35.3 ANALGESICS
27 Figure 35.19 One brand of soluble aspirin. 35.3 ANALGESICS
28 35.4 PROBLEMS WITH DRUGS SIDE EFFECTS OF DRUGS Drugs may have undesirable side effects. Let us look at some examples. Aspirin irritates the stomach. Some cough mixtures contain codeine. These may cause drowsiness and possible addiction.
29 Figure 35.21 This cough mixture contains a little codeine. 35.4 PROBLEMS WITH DRUGS
30 A35.3 We should take aspirin after meal, together with a lot of water or milk. DRUG ABUSE What is drug abuse? Drug abuse includes the following: Obtaining and using drugs (which should be prescribed) without a doctor’s prescription. Taking drugs for no medical reasons. 35.4 PROBLEMS WITH DRUGS
31 Taking drugs exceeding the recommended dosage. Taking a hypnotic or tranquilliser continually for a long period of time, without a doctor’s guidance. Sniffing solvents (e.g. glue, thinner, petrol). Taking illegal drugs (e.g. cannabis, cocaine, heroin and LSD). (This is particularly dangerous and will surely lead to early death.) 35.4 PROBLEMS WITH DRUGS
32 Figure 35.22 Some commonly abused drugs in Hong Kong. 35.4 PROBLEMS WITH DRUGS
33 DRUG DEPENDENCE A person addicted to a drug is either physically or psychologically dependent on the drug, or both. Physical dependence Psychological dependence 35.4 PROBLEMS WITH DRUGS
34 The following guiding questions may be useful for this discussion: (1)What are drugs? (2)What are the main types of drugs and their uses? (3)What are the side effects of drugs? (4)What is drug abuse? (5)What are the harmful effects of drug abuse? (6)Is drug abuse serious in Hong Kong? 35.4 PROBLEMS WITH DRUGS Activity 4
35 HARMS OF DRUG ADDICTION Harm to drug addicts themselves Harm to families of drug addicts Harm to society DRUG ABUSE IN HONG KONG In recent years, there has been a rising trend in the number of young people taking illegal drugs. 35.4 PROBLEMS WITH DRUGS
36 Figure 35.23 Government posters against drug abuse. 35.4 PROBLEMS WITH DRUGS
37 35.5 HAZARDS OF CIGARETTE SMOKING SMOKING CAN KILL You may have seen many times the government health warning: ‘Smoking can kill’. This warning is no exaggeration at all.
38 Figure 35.24 Hong Kong Government health warning: ‘Smoking can kill.’ 35.5 HAZARDS OF CIGARETTE SMOKING
39 Figure 35.25 A government anti-smoking poster. 35.5 HAZARDS OF CIGARETTE SMOKING
40 TRAPPING CIGARETTE SMOKE We can trap smoke from a lit cigarette using a ‘cigarette smoking machine’. 35.5 HAZARDS OF CIGARETTE SMOKING
41 Figure 35.26 A ‘cigarette smoking machine’. 35.5 HAZARDS OF CIGARETTE SMOKING
42 Experiment results show that high-tar cigarettes without filters give out more tar than low-tar cigarettes with filters. Besides, smokers inhale more harmful substances than passive smokers do. HARMFUL SUBSTANCES IN CIGARETTE SMOKE Smoking produces more than 4000 chemicals. The main products are: Gases (or vapours) Carbon dioxide Carbon monoxide Polycyclic aromatic hydrocarbons (PAHs) 35.5 HAZARDS OF CIGARETTE SMOKING
43 Tar Nicotine Particulates 35.5 HAZARDS OF CIGARETTE SMOKING
45 A35.4 Tar. A35.5 6 35.5 HAZARDS OF CIGARETTE SMOKING
46 Activity 6 Discussion could be based on the following points: (1)Why do people smoke? (2)Should smoking be banned completely? Why? (3)Should smoking be restricted (e.g. in public areas)? (4)If smoking is to be restricted, how should this be done? (5)Should cigarette advertising be restricted? Why? (6)Is restriction on cigarette advertising a violation of freedom of speech? 35.5 HAZARDS OF CIGARETTE SMOKING
47 (7)Should sponsorship for entertainments from cigarette companies be forbidden? (8)Do you think that the health hazard warnings on cigarette smoking mentioned on cigarette packets and advertisements are effective? 35.5 HAZARDS OF CIGARETTE SMOKING
48 SUMMARY 1.A drug is a substance which changes the state or function of the human body. 2.Anti-acids are drugs that can relieve stomach trouble caused by excess acid in the stomach. Milk of magnesia, with magnesium hydroxide as the active ingredient, is a common anti-acid. 3.Aspirin is a common painkiller, with acetylsalicylic acid as the active ingredient. Panadol is another common painkiller, with paracetamol as the active ingredient. 4.Drugs may have adverse side effects. SUMMARY
49 SUMMARY 5.Drug abuse is very dangerous. 6.There are two types of drug dependence — physical dependence and psychological dependence. 7.Smoking of cigarettes releases many harmful substances, including: Carbon monoxide Polycyclic aromatic hydrocarbons Tar Nicotine Particulates