Question
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- (a) Enumerate the various groups of Anti-thyroid Drugs used in clinical practice. Describe the mechanism of action and adverse effects of any one of these groups. Describe briefly the management of Thyroid Storm. ( 4 mark(s)
- (b) Human insulin. 2 mark(s)
Answer
a) Anti-thyroid drug groups, one group’s MOA/AE, and thyroid storm management
| Group | Examples |
|---|---|
| Thioamides | Carbimazole, Methimazole, Propylthiouracil |
| Iodides | Lugol’s iodine |
| Radioactive iodine | I-131 |
| Beta-blockers | Propranolol |
Thioamides — MOA and adverse effects: inhibit thyroid peroxidase, blocking oxidation/organification of iodide and coupling of iodotyrosines, reducing T3/T4 synthesis. Adverse effects: hepatotoxicity, agranulocytosis, rash.
Thyroid storm management: high-dose propranolol (adrenergic symptom control), propylthiouracil (blocks synthesis, plus peripheral T4-to-T3 conversion), iodide solution (given after the thioamide, Wolff-Chaikoff effect), corticosteroids (blocks peripheral conversion, covers relative adrenal insufficiency), and supportive care.
b) Human insulin Recombinant DNA-derived insulin, structurally identical to endogenous human insulin, avoiding the immunogenicity of older animal-derived insulins. Available as regular (soluble, short-acting) and NPH (isophane, intermediate-acting) formulations, now largely supplemented by newer insulin analogs for better physiological mimicry, but still widely used and effective.