Migraine calcium channel blockers

Calcium Channel Blockers. The calcium channel blockers work by blocking the influx of calcium, an excitatory ion, into the cell. The first calcium channel blocker, verapamil (Calan), was introduced in the 1960s. Others, including diltiazem, nifedipine, and nimodipine, are now available. The calcium channel blockers have been used to treat a variety of medical conditions including high blood pressure, cardiac pain (angina) and arrhythmias, migraines, seizure disorders, and premature labor. 

Drugs useful in prophylaxis of migraine are P-adrenergic blockers (usually propranolol), methysergide, calcium channel blockers. 

In addition to angina, calcium channel blockers have well-documented efficacy in hypertension (see Chapter 11) and supraventricular tachyarrhythmias (see Chapter 14). They also show moderate efficacy in a variety of other conditions, including hypertrophic cardiomyopathy, migraine, and Raynaud s phenomenon. Nifedipine has some efficacy in preterm labor but is more toxic and not as effective as atosiban, an investigational oxytocin antagonist (see Chapter 17). 

Propranolol, amitriptyline, and some calcium channel blockers have been found to be effective for the prophylaxis of migraine in some patients. They are of no value in the treatment of acute migraine. The anticonvulsants valproic acid and topiramate (see Chapter 24) have... 

Calcium channel blockers, such as verapamil (Calan , Covera , Isoptin , Verelan), diltiazem (Cardizem , Dilacor , Tiazac ), and nimodipine (Nimotop ), inhibit the flow of calcium ions into the cells that line blood vessel walls. This changes the way the blood vessels surrounding the brain dilate and constrict and provides relief from migraines. 

Diphenylalkylamines Verapamil [ver AP a mill] is the only member of this class that is currently approved in the United States. Verapamil is the least selective of any calcium channel blocker, and has significant effects on both cardiac and vascular smooth-muscle cells. It is used to treat angina, supraventricular tachyarrhythmias, and migraine headache. 

A 25-year-old woman with a history of migraine headaches was started on a calcium channel blocker 6 months ago for prophylaxis therapy. She now reveals that she has been having problems with constipation since starting therapy. In addition, she says that her gums are "overgrowing." PMH Depression and diabetes. Which calcium channel blocker is the most likely cause of her side effects ... 

Verapamil, proprietaiy name Calan, is a calcium channel blocker that is effective in the treatment of various cardiovascular disorders, including angina (classical and variant), arrhythmias (paroxysmal supraventricular tachycardia), atrial flutter, atrial fibrillation, hypertrophic cardiomyopathy (idiopathic hypertrophic subaortic stenosis), hypertension, congestive heart failure, and Raynaud s phenomenon, along with the preservation of ischemic myocardium and the treatment of migraine headaches. 

The P-blockers propranolol and timolol are FDA-approved for migraine prophylaxis, but other drugs in the class are also as effective.46 Cautious dosage titration is advised for those patients who do not have other indications for P-blocker use. Rizatriptan interacts with propranolol and thus dosages must be titrated downward, or another triptan chosen for abortive therapy.36 Comorbid reactive airway disease is a relative contraindication to P-blocker prophylaxis, and patients with cardiac conduction disturbances should be closely monitored. Calcium channel antagonists are often used when patients cannot tolerate P-blockers. They are purported to beneficially... 

---