Acetazolamide 250mg Tablets – Altitude Sickness Prevention (14 or 28 Tablets)

Acetazolamide is a prescription-only medicine that can reduce the risk of acute mountain sickness (altitude sickness) for adults travelling to 2,500 metres or higher. It is taken as half a 250mg tablet (125mg) twice a day, alongside a gradual ascent. At Ways Pharmacy it is supplied only after a pharmacist has reviewed your route, ascent plan and health and confirmed that it is suitable for you.

How to access this medicine

1. Start your free online assessment. Answer the health questions online about your destination, highest altitude, planned rate of ascent, health and current medicines, and confirm your identity (upload photo ID, or show it on a video call).
2. Pharmacist reviews and speaks with you. A GPhC-registered pharmacist contacts you by phone or video to confirm whether the medicine is suitable.
3. If suitable, order and pay on this page. Once the pharmacist confirms the medicine is suitable, you order and pay on this page, or call 020 8106 7084. If it is not suitable — including when the pharmacist gives advice only — you pay nothing, and the pharmacist explains your other options. If you have already paid and the pharmacist finds the medicine is not suitable, you receive a full refund.
4. We post your medicine or you collect it. Orders placed by 3pm on a weekday are posted the same day (see our shipping policy), or you can collect from Holborn.

There is no separate consultation fee. If the medicine you chose is not suitable, the pharmacist may suggest another option.

About this medicine

The pharmacist works out how many days you need from your itinerary and supplies the pack that covers your trip, avoiding more than you need. If you ordered 28 tablets but your trip needs only 14, you receive 14 and we refund the difference.

Dosage

• Adults aged 18 and over: 125mg (half a 250mg tablet) twice a day, morning and evening, swallowed with water, with or without food
• Start 1–2 days before you begin to ascend, continue during the ascent, and keep taking it for at least 48 hours after you reach your highest altitude
• If you miss a dose, take it when you remember, but do not take two doses together

Acetazolamide is licensed in the UK for other conditions. Using it to prevent altitude sickness is outside its product licence (off-label) but is accepted travel-medicine practice; the pharmacist will explain this to you before supply. It reduces the risk of altitude sickness but does not remove it, and it does not replace acclimatisation: ascend gradually where you can, and if symptoms develop, do not go higher.

Warnings and who should not take this medicine

• Anyone allergic to acetazolamide or to sulfonamide ("sulfa") medicines
• People with severe kidney or liver disease, a low sodium or potassium level, or Addison's disease
• Anyone who is pregnant or breastfeeding
• Anyone who has had a serious reaction to acetazolamide before
• People under 18 — please ask your GP or a travel medicine specialist
• Kidney stones, diabetes, lung disease, glaucoma or epilepsy, and older age, need individual assessment and may mean you should see your GP first
• Tell the pharmacist about all your medicines, especially diuretics, lithium, high-dose aspirin or epilepsy medicines

At altitude: a severe headache, repeated vomiting, breathlessness at rest, a cough, confusion or difficulty walking in a straight line can be signs of high altitude cerebral or pulmonary oedema. Descend immediately and get emergency medical help. This medicine is for prevention only and does not treat altitude sickness.

Possible side effects

Common side effects are tingling or pins and needles in the hands, feet or face, passing more urine, a change in taste (especially fizzy drinks) and tiredness. Nausea and dizziness are less common. Stop taking it and get urgent medical help if you develop a rash, difficulty breathing or signs of an allergic reaction.

See our altitude sickness service in Holborn for ascent advice and frequently asked questions.

Regulatory information

• Legal status: Prescription-only medicine (POM), supplied under a Patient Group Direction after pharmacist assessment
• Pharmacy: Ways Pharmacy, 77 Southampton Row, London WC1B 4ET · GPhC-registered premises 9012227
• Patient information leaflet: electronic Medicines Compendium (emc)
• Report suspected side effects through the MHRA Yellow Card Scheme

This page gives factual information about a prescription-only medicine and is not an advertisement to the public. It is supplied only after a pharmacist has assessed that it is suitable for you.