Chapter 16 - The Use and Abuse of Drugs 

Drug

• Drug is an externally administered substance that alters the metabolism

  • Stimulants: Drugs which reduce the reaction time. (e.g. nicotine)

  • Depressants: increase the reaction time.

  • Narcotics: Addictive drugs

Addiction:

A state if the drug is not taken, the body shows physical dependence i.e. some signs and symptoms like muscle pain, vomiting and diarrhea called withdrawal symptoms.

Antibiotics:

A substance extracted from micro organisms to control bacterial infections.

1. Penicillin:

   It is extracted from the fungus called penicillium. Acts against a wide range of bacterial infections. Many bacterial have become resistant to penicillin today so the new derivatives of penicillin are being used against bacteria.

2. Streptomycin:

It is obtained from a bacterium called streptomycin.

• Antibiotics work by inferring the enzymes of bacteria involved in protein synthesis.

• They interfere the cell division

• They break down the bacterial cell walls

• Antibiotics do not work against viruses

• Overdose of antibiotic can have side effects

• If antibiotics are taken less than the recommended dose, bacteria develop resistance against them.

Types of Drugs:

1. HEROIN:

   • Strongly depressant

   • Reduces hunger, so malnutrition can occur

   • Sharing needles can spread infections like aids, hepatitis, etc.

   • It is an expensive drug and user develops tolerance against it.

   • The addict person ignores family and job, so many have limited sources of income, thus they get involved in theft.

   • Initially dulls the senses and produces feelings of well being.

   • Withdrawal symptoms include : watery eyes, stomach upset, muscular pain, vomiting, diarrhea and hallucinations.

2. ALCOHOL:

   • Depressant drug

   • Slows down the conduction of nerve impulses so increases reaction time.

   • It effects cerebrum causing loss of speech, or a person may become unconscious.

   • It effects medulla, it may cause death.

   • Increases acidity in stomach.

   • Can lead to stomach ulcers

   • If an alcoholic is smoker too, it increases chances of oral cancer.

   • It reduces sperm count, so leads to male sterility.

   • It causes vasodilation in the skin.

   • It reduces water potential of blood, a person feels thirsty and drinks more water, it can cause kidney failure.

   • It causes liver cirrhosis

   • For pregnant women, alcohol consumption leads to an underweight baby

   • Withdrawal symptoms of alcohol include: Tremors, high pulse rate, sweating, visual hallucinations and restlessness.

3. TOBACCO SMOKE:

   • Carbon Monoxide:

     - combines irreversibly with the hemoglobin to make carboxyhemoglobin. It reduces oxygen carrying capacity of blood causing tiredness and breathlessness.

   • Irritants:

     - stimulate the release of excessive mucus. It blocks the bronchioles and produces a state of difficult breathing called bronchitis.

   • Tar:

     - deposits on inner lining of alveoli and breaks the elastin surrounding alveoli. This state is called emphysema.

   • Nicotine:

     (i) stimulant

     (ii) narrows blood vessels

     (iii) makes blood cells sticky

     (iv) increases heart beat

     (v) cardiovascular diseases