What Is Verapamil?
Verapamil is a type of calcium channel blockers, which are mostly prescribed for people with high blood pressure. They can relax blood vessels and allow more blood to flow to the heart. This effect subsequently helps reduce blood pressure. In the past, this medication was used for preventing migraine and treating cluster headaches. Nevertheless, it is currently not approved for dealing with these health issues. 
What Is a Migraine?
A migraine is a type of headache characterized by a severe pulsing or throbbing pain, often on one side of your head. It is usually followed by other problems, such as sensitivity to sound and light, vomiting, and nausea. A migraine attack may last for a few hours up to a few days. In some cases, the symptoms may become so serious that they would affect your daily life. A common warning symptom of migraine is an aura happening with or before a headache. This aura may include disturbances, such as blind spots, flashes of light, trouble speaking, or tingling sensation in the leg, arm, or face. Taking medications, along with lifestyle changes and home remedies, can help prevent a migraine attack or reduce pain.