Pizotifen is chiefly indicated for the prophylactic treatment of vascular headaches of the migraine type such as classical migraine, common migraine and cluster headache.
Anti-histamine Preparations, Other drugs for migraine
Pizotifen is a tri-cyclic compound possessing structural similarities to cyproheptadine and tri-cyclic antidepressants. It is given orally for the prophylaxis of migraine and for the prevention of headache attacks during cluster periods. It is not effective in acute attacks of migraine.
The prophylactic effect of Pizotifen is associated with its ability to modify the humoral mechanisms of headache. It inhibits the permeability increasing effect of serotonin and histamine on the affected cranial vessels, thereby checking the transudation of plasmakinin so that the pain threshold of the receptor is maintained at “normal” levels. In the sequence of events leading to migraine attack, depletion of plasma serotonin contributes to loss of tone of extracranial vessels. Pizotifen inhibits serotonin re-uptake by the platelets, thus maintaining plasma serotonin and preventing the loss of tone and passive diffusion of the extracranial arteries.
Adults: The initial adult dose is 1.5 mg daily, this may be taken at bed time as a single dose or in three divided doses. Dosage can be adjusted according to individual patients’ requirements up to a maximum of 4.5 mg daily. Up to 3 mg may be given as a single daily dose.
Children: Up to 1.5 mg daily, usually as a divided dose. Use of 1.5 mg at a time is not recommended, but up to 1 mg has been given as a single daily dose at night.
Patients should be warned that their tolerance to alcohol may be lowered. Pizotifen may increase and prolong the drowsiness that occurs as an adverse effect of concurrently used tranquilizers, hypnotics and antidepressants. It should not be used in patients receiving monoamine oxidase inhibitors.
Although its anticholinergic activity is relatively weak, Pizotifen should probably not be administered in presence of narrow angle glaucoma or prostate hypertrophy. It should not be given in patients with hypersensitivity to this drug.
Drowsiness is the most common side effect and also increased appetite, which may lead to increase in body weight. Other side effects are, dizziness, dry mouth, nausea, constipation, which are rare. In children central nervous system (CNS) stimulation may occur.
Information of using Pizotifen in pregnancy is limited, so it should only be used during pregnancy under compelling circumstances and it is not recommended to the nursing mother.
Patients should be cautioned about the possibility of drowsiness and informed of its significance in driving vehicles and operation of machineries. Pizotifen may enhance the central effects of sedatives, hypnotic, antihistamines and alcohol. Dose adjustment may be required in patients with renal insufficiency.
Store at or below 25˚C , protect from direct light. Keep all medicine out of the reach of children.