Acetazolamide (Ménière's Disease)

How it works

By inhibiting carbonic anhydrase it reduces bicarbonate formation, producing a weak diuresis, lowering aqueous humour and cerebrospinal fluid production, and causing a mild metabolic acidosis that underlies its benefit in altitude sickness.

Prescribing in practice

• It is a sulfonamide, so use caution in sulfonamide allergy and watch for the associated serious skin and blood reactions.
• It predictably causes metabolic acidosis, paraesthesia, taste disturbance and hypokalaemia, and increases the risk of renal stones; monitor electrolytes and avoid in significant renal or hepatic impairment.
• Use caution alongside other drugs that lower potassium and in conditions where acidosis or electrolyte shifts would be harmful.

Monitoring

Monitor serum electrolytes (particularly potassium and bicarbonate) and renal function, especially with prolonged use or in those at risk of acidosis or stones.

Counselling the patient

• Tingling of the hands, feet or face and an altered taste (for example of fizzy drinks) are common and usually harmless.
• Drink adequate fluids, and report any rash, severe sore throat, loin pain or blood in the urine.

Evidence & guidelines

Used across several specialties (ophthalmology, neurology, ENT and altitude medicine); for acute mountain sickness prevention its benefit is supported by trial evidence and travel-medicine guidance.