Medication to prevent altitude sickness

Acetazolamide is commonly prescribed when rapid ascent cannot be avoided or a traveller has a relevant history. It helps the body acclimatise by changing acid balance and stimulating breathing. It does not hide every symptom, replace descent, or make an aggressive itinerary safe.

The decision depends on sleeping elevation, how quickly the route rises, opportunity for acclimatisation, previous reactions at a similar ascent rate, and how hard evacuation would be. Fitness does not reliably protect against altitude sickness. A clinician may also consider heart or lung disease, kidney problems, pregnancy, sleep apnoea, and current medicines.

Other prescription medicines have specialised roles, including emergency treatment or prevention for people with a history of severe altitude illness. They require individual instructions because side effects, interactions, and rebound symptoms can affect safe use.

Obtain the medicine before travel and follow the prescribed timing rather than improvising on the mountain. Review allergies, kidney conditions, pregnancy or breastfeeding, and all regular or occasional medicines with the prescriber. Ask what common effects to expect and which reaction means you should stop and seek help.

Build acclimatisation time into the trip, keep early exertion gentle, and avoid climbing to sleep higher while unwell. Agree beforehand who will monitor symptoms and how the group will descend. A tablet is one layer of preparation; route flexibility and honest symptom reporting are equally important.

Stop ascending when headache occurs with nausea, dizziness, fatigue, or poor appetite. Rest at the same elevation and descend if symptoms worsen or do not settle. Do not take extra doses unless your clinician's plan specifically directs this.

Confusion, unusual behaviour, difficulty walking straight, breathlessness at rest, chest tightness, or a wet cough requires emergency descent and medical care. Give supplemental oxygen if it is available and someone knows how to use it, while arranging evacuation. Medication must not delay these actions.

Bring your route and sleeping elevations. Ask whether prevention suits your risk, when to start and stop it, what to do after a missed dose, and whether tingling, altered taste, frequent urination, or stomach upset would change the plan. Clarify which rescue medicines require training and which symptoms mandate descent regardless of treatment.