Pifen 0.5 mg is indicated for the prophylactic treatment of migraine-related vascular headaches, including classical migraine, common migraine, and cluster headache. It is used to prevent migraine attacks but is not effective for relieving an ongoing migraine attack.

Pizotifen is a tricyclic compound. It acts as a competitive antagonist of serotonin receptors. It also has antihistamine, antibradykinin, and mild anticholinergic properties. In addition, it has appetite-stimulating effects.

Pizotifen works by blocking the peripheral effects of serotonin and histamine that increase the membrane permeability of cranial blood vessels and promote plasmakinin transudation, which are involved in migraine pain. It also helps modify pain thresholds in migraine. By blocking 5-HT receptors, Pizotifen reduces serotonin-mediated cranial vasoconstriction and decreases serotonin-induced platelet aggregation and function. There is also evidence that it inhibits the peripheral effects of bradykinin. Pizotifen may also inhibit serotonin reuptake by blood platelets, which helps regulate vascular tone and reduces passive distension of extracranial arteries. Its appetite-stimulating effect is believed to result from metabolic actions rather than direct stimulation of the appetite center.

Adults: Usually 1.5 mg daily. This may be taken as a single dose at night or in three divided doses. Dosage should be adjusted to the individual patient requirements up to a maximum of 4.5 mg daily. Up to 3 mg may be given as a single dose.

Children (aged over 2 years): Up to 1.5 mg daily, usually as a divided dose, although up to 1 mg has been given as a single dose at night.

Pizotifen is contraindicated in patients with known hypersensitivity to Pizotifen or any of its components.

The most commonly reported side effects are increased appetite, weight gain, and drowsiness.

Information regarding the use of Pizotifen during pregnancy is limited, although no harmful effects have been clearly reported. It should be used during pregnancy only if the expected benefit to the mother outweighs the possible risk to the fetus. The safety of Pizotifen during breastfeeding has not been established. Therefore, mothers should avoid using it while breastfeeding.

Caution should be taken in patients with urinary retention or renal impairment. Drowsiness caused by Pizotifen may affect the ability to drive vehicles or operate machinery. Alcohol may enhance the sedative effect of Pizotifen.

Antihistamine preparations, other drugs for migraine

Store in a dry place away from heat and light. Keep out of reach of children.