Chemistry in Medicine — Analgesics, Antipyretics, Antibiotics, Antiseptics, Disinfectants and Antacids

Why Medicines Are a Chemistry Topic

Every medicine is a chemical chosen for what it does to the body, so exams classify drugs by action, not by brand: does it relieve pain, lower fever, kill bacteria, protect a wound or neutralise acid? Learn the classes and their standard examples, and most questions answer themselves.

Two ideas cause most mistakes. First, one drug can belong to several classes — aspirin relieves pain, lowers fever, reduces inflammation and thins the blood. Second, the same substance can change class with concentration: a 0.2% phenol solution is an antiseptic, while a 1% solution is a disinfectant.

This topic covers the six classes papers ask about most — analgesics, antipyretics, antibiotics, antiseptics, disinfectants and antacids — plus the few names from tranquillisers and antihistamines that keep reappearing.

1. A 0.2% solution of phenol is used as:

2. Who discovered penicillin?

3. Chemically, milk of magnesia is:

4. Which of the following is a narcotic analgesic?

5. Aspirin is chemically known as:

6. Antibiotics are NOT effective against which of the following?

7. The antiseptic Dettol is a mixture of:

8. Which of the following antibiotics is bacteriostatic rather than bactericidal?