Altitude illness medication: what travellers should know

A clinician may prescribe acetazolamide before and during ascent to support acclimatisation, particularly when a rapid itinerary cannot be avoided or a traveller has previously developed altitude illness. It can cause tingling, increased urination, and a change in the taste of fizzy drinks. Dexamethasone may be used in selected situations, including serious illness, but it does not help the body acclimatise and symptoms can return if it is stopped while the person remains high.

The right option depends on the planned sleeping altitude, speed of ascent, medical history, pregnancy status, allergies, and other medicines. Pain relief or anti-nausea medicine may ease individual symptoms without correcting the low-oxygen stress causing the illness.

Arrange a travel health consultation before departure if your route reaches high sleeping elevations or allows little time to acclimatise. Take prescribed medicine exactly as directed, learn expected side effects, and carry enough for the planned route plus reasonable travel disruption. Do not start someone else's tablets or use medication to push higher when symptoms are developing.

At altitude, avoid further ascent if headache, nausea, unusual fatigue, dizziness, or poor sleep appears. Rest at the same elevation, stay comfortably hydrated, avoid alcohol and sedatives, and reassess. Descend if symptoms worsen or do not settle.

Confusion, inability to walk in a straight line, severe breathlessness at rest, blue or grey lips, chest tightness, collapse, or coughing frothy fluid can signal life-threatening altitude illness. Begin descent with assistance and seek emergency medical help immediately; oxygen may be needed if available. Never leave an unwell person alone or wait for tablets to take effect before descending.

Ask whether your itinerary makes preventive medicine appropriate, when to begin and stop it, which side effects should prompt advice, and whether your health conditions or regular medicines change the plan. Also clarify what to do after a missed dose and where emergency care is available along the route.