Pizotifen

Pizotifen (INN) or pizotyline (USAN), trade name Sandomigran, is a benzocycloheptene based drug used as a medicine, primarily as a preventative to reduce the frequency of recurrent migraine headaches.

Uses
The main medical use for pizotifen is for the prevention of vascular headache including migraine and cluster headache. Pizotifen is one of a range of medications used for this purpose, other options include propranolol, topiramate, valproic acid and amitriptyline. While pizotifen is reasonably effective, its use is limited by side effects, principally drowsiness and weight gain, and it is usually not the first choice medicine for preventing migraines, instead being used as an alternative when other drugs have failed to be effective.

Other applications for which pizotifen may be used include as an antidepressant, or for the treatment of anxiety or social phobia. Animal studies also suggest that pizotyline could be used in the treatment of serotonin syndrome or MDMA overdose in a similar manner to the closely related antihistamine/antiserotonin drug cyproheptadine.

Adverse effects
Side effects include sedation, dry mouth, drowsiness, increased appetite and weight gain. Occasionally it may cause nausea, headaches, or dizziness. In rare cases, anxiety, aggression and depression may also occur.

Contraindications
Pizotifen is contraindicated in patients who suffer from hypersensitivity to any of its components, also Pizotifen is contraindicated in gastric outlet obstruction, pregnancy, angle-closure glaucoma and difficulty urinating.

Mechanism
Pizotifen is a serotonin antagonist acting mainly at the 5-HT2A and 5HT2C receptors. It also has some activity as an antihistamine as well as some anticholinergic activity.