American Board of Internal Medicine (ABIM) Certification Practice Exam

What is the drug of choice for preventing cluster headaches?

1. Topiramate

2. Verapamil

3. Beta Blocker

4. Carbamazepine

The correct answer is: Verapamil

Verapamil is recognized as the drug of choice for the prevention of cluster headaches. This classification of headaches is characterized by severe, unilateral pain that occurs in clusters or episodes, often with periods of remission. Verapamil, a calcium channel blocker, has established efficacy in reducing the frequency and severity of these headache attacks. Its effectiveness in cluster headache prophylaxis is attributed to its ability to stabilize vascular tone and decrease the activity of the hypothalamus, which is implicated in cluster headaches. In clinical practice, it is frequently used as the first-line agent for chronic cluster headaches, often in a higher dosage than typically utilized for cardiovascular indications. Topiramate is also effective for migraine prevention and can sometimes be used for cluster headaches, but verapamil remains the more established first-line choice based on current guidelines. Beta blockers, while useful in migraine prophylaxis, do not have the same level of evidence supporting their use for cluster headaches. Carbamazepine, primarily indicated for trigeminal neuralgia and certain seizure disorders, is not typically utilized for cluster headaches and lacks supporting evidence for this indication.