Flunarizine

Indications
Flunarizine is indicated for
Prophylaxis of classic (with aura) or common (without aura) migraine
Symptomatic treatment of vestibular vertigo (due to a diagnosed functional disorder of the vestibular system).
Peripheral Vascular Disease (PVD)
Motion sickness
Refractory epilepsy resistant to conventional antiepileptic therapy.

Therapeutic Class
Miscellaneous prophylactic migraine preparations

Pharmacology
Flunarizine is the difluorinated derivative of cinnarizine. It is a seletive calcium channel antagonist and has H1-receptor blocking action. By reducing excessive transmembrane influx of calcium Flunarizine prevents cellular calcium overlod. It does not interfere with normal cellular calcium homeostasis. Flunarizine also has some antihistaminic and sedative properties.

Dosage & Administration
Migraine Prophylaxis:
Starting Dose: 10 mg at night in patients less than 65 years of age and 5 mg daily in patients older than 65 years. If, during this treatment depressive, extrapyramidal or other unacceptable symptoms occur, administration should be discontinued. If, after 2 months of this initial treatment, no significant improvement is observed, the patient should be considered a non-responder and administration should be discontinued.
Maintenance Treatment: If a patient is responding satisfactorily and if a maintenance treatment is needed, the dose should be decreased to 5 days treatment at the same daily dose with two successive medicine free days every week. Even if the prophylactic maintenance treatment is successful and well tolerated, it should be interrupted after 6 months and it should be re-initiated only if the patient relapses.
Peripheral Vascular disease: 10 mg twice daily, up to 30 mg per day if required.
Vertigo & motion sickness: 10-20 mg daily for adults and 5 mg daily for children (> 40 kg).
Epileptic seizure: 15-20 mg daily in adults and 5 to 10 mg daily for children as an add-on therapy

Interaction
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.

Contraindications
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.

Side Effects
Flunarizine is well tolerated and seldom causes serious side effects. The main adverse effects experienced by the patients are as follows:
Central nervous system: Depression, drowsiness, sedation, and anxiety.
Gastrointestinal: Heart burn, nausea, emesis, dry mouth, gastralgia.
Miscellaneous: Weight gain, and/or increased appetite, asthenia, muscle aches, skin rash, and galactorrhea in female patients on oral contraceptives.

Pregnancy & Lactation
Safety in pregnancy and lactation has not been established.

Precautions & Warnings
Since sedation or drowsiness occur in some patients during treatment with flunarizine hydrochloride, patients should be cautioned against activities which require alertness or rapid, precise responses (e.g. operating machinery or a motor vehicle) until the response to the drug has been determined.

Storage Conditions
Store at a cool & dry place, protected from light and moisture. Keep out of reach of the children.