Flunarizine

Mechanism :

Flunarizine is classified as a calcium channel blocker. Flunarizine is a selective calcium entry blocker with calmodulin binding properties and histamine H1 blocking activity.
Flunarizine inhibits the influx of extracellular calcium through myocardial and vascular membrane pores by physically plugging the channel. The decrease in intracellular calcium inhibits the contractile processes of smooth muscle cells, causing dilation of the coronary and systemic arteries, increased oxygen delivery to the myocardial tissue, decreased total peripheral resistance, decreased systemic blood pressure, and decreased afterload.

Indication :

• Migraine prophylaxis
• Occlusive peripheral vascular disease
• Vertigo of central and peripheral origin

Contraindications :

Known hypersensitivity to flunarizine is a contraindication for its use. Also contraindicated in patients with a history of depressive illness, with pre-existing symptoms of Parkinson disease or other extrapyramidal disorders and hepatic impairment.

Dosing :

Adverse Effect :

Weight gain, drowsiness, fatigue, increased appetite, depression, extrapyramidal symptoms, heartburn, insomnia, nausea, galactorrhoea, anxiety, dry mouth and skin rash.

Interaction :

Oral contraceptives: Galactorrhoea has been reported in few women on oral contraceptives
Carbamazepine and Phenytoin: Hepatic enzyme inducers such as carbamazepine and phenytoin may interact with flunarizine by increasing its metabolism.
CNS depressants, Triprolidine and Flunarizine: May increase adverse/toxic effects due to additivity. Monitor for increased CNS depressant effects during concomitant therapy.

Hepatic Dose :