Paper I
Question
(
- (a) Alpha blockers ( 4 mark(s)
- (b) Enumerate the uses of prostaglandins 4 mark(s)
Answer
a) Alpha blockers Examples: Prazosin, Terazosin, Doxazosin (alpha-1 selective); Phenoxybenzamine (non-selective, irreversible); Tamsulosin (alpha-1A selective, uroselective).
MOA: block alpha-1 adrenergic receptors on vascular/prostatic smooth muscle, preventing catecholamine-mediated vasoconstriction/smooth muscle contraction.
Uses: hypertension (Prazosin), benign prostatic hyperplasia (Tamsulosin — relieves bladder neck/prostatic smooth muscle obstruction), pheochromocytoma (Phenoxybenzamine, pre-operative).
Adverse effects: first-dose hypotension/syncope, dizziness, reflex tachycardia, nasal congestion.
b) Uses of prostaglandins
- Obstetric: Dinoprostone/Misoprostol for cervical ripening and labour induction; Carboprost for postpartum hemorrhage.
- Cardiovascular: Alprostadil to maintain ductal patency in ductus-dependent congenital heart disease.
- Gastric protection: Misoprostol, co-prescribed with NSAIDs.
- Ophthalmic: Latanoprost for open-angle glaucoma.
- Erectile dysfunction: Alprostadil.

