Which medication is contraindicated for migraine prophylaxis?

Verapamil is primarily known as a calcium channel blocker and is typically used to manage hypertension and certain types of angina. While it has some applications in migraine treatment, it is not commonly indicated or employed for migraine prophylaxis. The other medications listed—topiramate, propranolol, and gabapentin—are more established in their roles for preventing migraine attacks.

Topiramate is an anticonvulsant that has shown efficacy in reducing the frequency of migraine attacks. Propranolol is a beta-blocker that is frequently used as a first-line medication for migraine prophylaxis due to its success in decreasing the frequency and severity of these headaches. Gabapentin, while less commonly used compared to the others, has shown some effectiveness in migraine prevention as well, especially in patients who also experience neuropathic pain.

In summary, while verapamil might have some role in specific migraine cases, it is not a standard choice for prophylaxis, making it the correct answer for this question regarding contraindications for migraine prophylaxis.