Pizotifen(BC-105): A Review of its Pharmacological Properties and its Therapeutic Efficacy in Vascular Headaches

Abstract

Synopsis: Pizotifen2 is a benzocycloheptathiophene derivative possessing a strong antagonistic action against certain biogenic amines. It is indicated in the prophylactic treatment of severe and recurrent vascular headaches, but is of no value in the treatment of acute attacks. Pizotifen is structurally similar to cyproheptadine and the tricyclic antidepressants, and has been shown to exert strong antiserotonin and antihistaminic effects, together with a weak anticholinergic activity. These antagonistic effects are evidently related to the drug’s mode of action in reducing the occurrence of migrainous attacks, as it is now considered that the pathogenesis of migraine involves the action of a number of vasoactive substances (including serotonin, histamine, noradrenaline, acetylcholine and bradykinin) on the microcirculation. Most, but not all, therapeutic trials have obtained reasonably good results in patients suffering from either classic or common migraine and also in patients with cluster headache (migrainous neuralgia). Controlled studies have in general shown pizotifen to be significantly more effective than a placebo, but usually less effective than methysergide. In some cases however, patients who have failed to respond to methysergide have responded to pizotifen. In other forms of headache, such as tension or muscle contraction headache, post-traumatic headache, inflammatory headache and trigeminal neuralgia, pizotifen has generally had little effect. With usual therapeutic doses (1.5 to 3 mg daily) drowsiness and increased appetite (with weight gain) frequently occur. In the majority of patients, these symptoms usually prove mild and tend to diminish during prolonged therapy. © 1972, Adis Press. All rights reserved.