Description

Flunarizine is the difluorinated derivative of cinnarizine. It is a selective calcium channel antagonist. By reducing excessive transmembrane influx of calcium Flunarizine prevents cellular calcium overload. It does not interfere with normal cellular calcium homeostasis. Flunarizine also has some antihistaminic and sedative properties. It binds at an affinity of 99% to plasma protein.

Galactorrhoea has been reported in few women on oral contraceptives within the first two months of Flunarizine treatment. Hepatic enzyme inducers such as Carbamazepine and Phenytoin may interact with flunarizine by increasing its metabolism. So an increase in dosage of flunarizine may be required.

Hypersensitivity to Flunarizine. Flunarizine is contra-indicated in patients with a history of depressive illness, or with pre-existing symptoms of Parkinson's disease or other extrapyramidal disorders.

Drowsiness and/or fatigue, as well as weight gain and/or increased appetite may occur. The following adverse experiences have been reported during chronic treatment with Flunarizine: depression, of which female patients with a history of depressive illness may be particularly at risk; extrapyramidal symptoms (such as bradykinesia, rigidity, akathisia, orofacial dyskinesia, tremor), of which elderly patients seem particularly at risk. Infrequently reported adverse reaction are: heartburn; nausea; gastralgia; insomnia; anxiety; galactorrhoea; dry mouth; muscle ache; skin rash.

Safety in pregnancy and lactation has not been established.

Flunarizine may lead to drowsiness which is aggravated by the simultaneous intake of alcohol or other central nervous system depressants. Patients should be cautioned against driving motor vehicles or performing other potentially hazardous tasks where a loss of mental alertness may lead to accidents. Flunarizine is not suited for aborting a migraine attack. The possible occurrence of an attack is therefore no reason to increase the dose of Flunarizine. This treatment may give rise to extrapyramidal and depressive symptoms and reveal Parkinsonism, especially in predisposed patients such as the elderly. Flunarizine should therefore be used with caution in such patients.

Miscellaneous prophylactic migraine preparations