Pharmacology · single question
DAY 2 — CASE 5: What is the mechanism of action of carbamazepine (used for trigeminal neuralgia)?
Show answer and explanation
Correct answer: C. Sodium channel blocker
- A. GABA receptor agonism (like benzodiazepines) is a different anticonvulsant mechanism.
- B. Potassium channel blockers (like 4-aminopyridine) are used for MS — not carbamazepine's mechanism.
- C. Carbamazepine (Tegretol) works by BLOCKING VOLTAGE-GATED SODIUM CHANNELS in neuronal membranes, stabilizing the membrane and reducing repetitive high-frequency firing of action potentials. This is the mechanism by which it controls trigeminal neuralgia (and seizures). It is the DRUG OF CHOICE for trigeminal neuralgia.
- D. Calcium channel blockers (nifedipine, verapamil) are used for hypertension/angina — not carbamazepine's mechanism.