First-line pharmacologic prophylaxis for cluster headaches is:

• A. Lithium
• B. Sumatriptan
• C. Topiramate
• D. Verapamil

Answer: (D)

Verapamil is used as the first-line preventive treatment for cluster headaches because calcium-channel blockade reliably lowers how often and how long the attacks occur. It likely works by dampening the neural and vascular excitability in the pain pathways activated during a cluster period, offering the strongest evidence among preventive options for both episodic and chronic forms. Treatment requires slow dose escalation with regular ECG monitoring because high doses can affect conduction andcause heart block, so clinicians titrate up while watching the rhythm. Common side effects include constipation, bradycardia, and lightheadedness. If verapamil isn’t suitable, alternatives like lithium can be considered for chronic clusters, but they’re not as consistently effective or as well tolerated; sumatriptan is used for abortive treatment during a cluster bout, and topiramate’s role as a preventive is less well established.