Betahistine Dihydrochloride

Indications
Betahistine is indicated for the treatment of Meniere’s syndrome, symptoms of which may include vertigo, tinnitus, hearing loss and nausea.

Therapeutic Class
Drugs used in meniere's diseases

Pharmacology
Betahistine acts as both partial histamine H1-receptor agonist and histamine H3-receptor antagonist in neuronal tissue. It improves the microcirculation in the labyrinth, thus reducing endolymphatic pressure.

Dosage & Administration
The usual initial dose: 8 mg to 16 mg three time's daily taken preferably with meals.
Maintenance dosage: Up to 48 mg daily have been recommended.
Betahistine is not recommended for use in children and adolescents below age 18 due to lack of data on safety and efficacy .

Interaction
There are no proven cases of hazardous interactions. There is a case report of an interaction with ethanol and a compound containing pyrimethamine with dapsone and another of potentiation of betahistine with salbutamol. Betahistine is a histamine analogue, concurrent administration of H1 antagonists may cause a mutual attenuation of effect of the active agents.

Contraindications
Betahistine is contraindicated in pheochromocytoma.

Side Effects
Betahistine is generally well tolerated and there is no known serious adverse effects. In some circumstances gastrointestinal disturbances, headache, rashes and pruritus have been reported.

Pregnancy & Lactation
Pregnancy: There is a very limited amount of data from the use of betahistine in pregnant women. Animal studies, though insufficient do not indicate direct or indirect harmful effects with respect to reproductive toxicity . As a precautionary measure, it is preferable to avoid the use of Betahistine during pregnancy.
Lactation: There is insufficient information on the excretion of betahistine in human milk. Betahistine should not be used during breast-feeding.

Precautions & Warnings
Caution should be exercised in patients with bronchial asthma and peptic ulceration.

Overdose Effects
Symptoms: Nausea, somnolence, abdominal pain, convulsion, pulmonary or cardiac complications.
Management: Supportive treatment.

Storage Conditions
Store in a cool and dry place, protected from light.