Flunarizine

Uses

Flunarizine is used 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.

Flunarizine is also used to associated treatment for these conditions: Severe Migraine

How Flunarizine works

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.

Dosage

Flunarizine dosage

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

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.

Toxicity

-Flunarizine should be used with care in patients with depression or those being prescribed other agents, such as phenothiazines, concurrently, which may cause extrapyramidal side-effects. -Acute overdosage has been reported and the observed symptoms were sedation, agitation and tachycardia. -Treatment of acute overdosage consists of charcoal administration, induction of emesis or gastric lavage, and supportive measures. No specific antidote is known.

Precaution

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.

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.

Elimination Route

85% following oral administration.

Half Life

18 days

Pregnancy & Breastfeeding use

Safety in pregnancy and lactation has not been established.

Contraindication

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.

Storage Condition

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

Innovators Monograph

You find simplified version here Flunarizine