betahistine dihydrochloride: clinical use

Prescribing considerations

• Confirm symptoms are consistent with Ménière’s syndrome; the selected generic product information states that betahistine is inappropriate for benign paroxysmal positional vertigo or dizziness caused by central nervous system disease.
• Not recommended below 18 years because safety and efficacy data are insufficient.
• Limited trial data exist in older people and renal or hepatic impairment; post-marketing experience does not suggest an adjustment is needed.
• Use caution with severe hypotension and where urticaria, rash or allergic rhinitis might be aggravated.

Contraindications and cautions

• Phaeochromocytoma
• Hypersensitivity to betahistine or any product excipient

Monitoring

• Monitor people with bronchial asthma carefully for clinical intolerance.
• Monitor those with active or previous peptic ulcer disease for gastrointestinal intolerance.
• Review symptom response, adverse effects and whether the diagnosis remains appropriate.

Clinical pharmacology

Betahistine is a partial H1-receptor agonist and H3-receptor antagonist with negligible H2 activity. It is readily absorbed, rapidly converted to inactive 2-pyridylacetic acid and eliminated mainly through urinary excretion of that metabolite. Food slows peak absorption without materially changing total absorption.

Formulation and product differences

• Both selected products are white, scored tablets, but only the selected generic product information explicitly states that its tablet can be divided into equal portions.
• Excipient combinations differ: the branded product includes propyl gallate and L-cysteine hydrochloride monohydrate, while the selected generic includes povidone and crospovidone.
• Storage instructions differ: the selected generic requires no special storage conditions, while the branded product specifies storage below 25°C in the original package.

Tablet

Route: Oral

Strengths: 8 mg, 16 mg