Diamox (Acetazolamide)

Vad är Diamox?

Diamox is the brand name for Acetazolamide, a carbonic anhydrase inhibitor that has been used in clinical medicine since the 1950s. In the context of travel health, Diamox is the best-evidenced pharmacological option for the prevention and treatment of acute mountain sickness (AMS) — an illness that can affect travellers, trekkers, and climbers who ascend rapidly to high altitudes.

Acute mountain sickness is caused by the physiological stress of reduced atmospheric oxygen pressure (hypoxia) at altitude. Symptoms typically begin within hours of arriving at high altitude and can include headache, nausea, dizziness, fatigue, and difficulty sleeping. In severe cases, AMS can progress to the potentially life-threatening conditions of high-altitude cerebral oedema (HACE) or high-altitude pulmonary oedema (HAPE).

Hur fungerar Diamox work?

Diamox inhibits the enzyme carbonic anhydrase, which plays a key role in acid-base regulation in the body. By inhibiting this enzyme, Diamox causes the kidneys to excrete bicarbonate into the urine, producing a mild metabolic acidosis (a slight decrease in blood pH).

This mild acidosis stimulates breathing — specifically, it increases ventilatory rate and depth. More frequent and deeper breathing raises blood oxygen saturation, which is the primary mechanism by which Diamox prevents and treats altitude sickness. In effect, Diamox helps the body adapt (acclimatise) to altitude more rapidly than it would otherwise.

The diuretic effect of Diamox (increased urine production) is a side effect of this mechanism rather than the primary therapeutic action.

Vem är Diamox for?

Diamox may be appropriate for travellers who:

• Plan to ascend to altitudes above 2,500–3,000 metres, particularly if rapid ascent is planned
• Have a history of previous altitude sickness
• Cannot follow a gradual ascent schedule due to time constraints (e.g., flying directly to a high-altitude destination)
• Are considering high-altitude trekking in regions such as Nepal, the Andes, Kilimanjaro, or high-altitude parts of the Tibetan Plateau

Diamox is not a substitute for gradual acclimatisation. The WHO and travel medicine guidelines consistently recommend that where feasible, a slow ascent profile — ascending no more than 300–500 metres per day above 3,000 metres, with rest days built in — remains the most effective strategy for preventing altitude sickness. Diamox is a complement to, not a replacement for, sensible ascent planning.

Diamox is not recommended for:

• Patients with known hypersensitivity to sulfonamides
• Patients with severe liver or kidney disease
• Patients with low blood sodium or potassium levels
• Pregnant women (discuss with a doctor if travel to altitude is unavoidable)

Dosering

For altitude sickness prevention in adults, typical guidance based on WHO and European travel medicine recommendations is:

Phase	Dose	Timing
Prevention	125–250 mg twice daily	Start 1–2 days before ascent
During ascent	Continue twice daily	Throughout ascent period
Post-arrival	Continue for 2 days at maximum altitude	Then taper as directed

Some travel medicine guidelines use 250 mg twice daily; others use 125 mg twice daily for improved tolerability. An independent doctor will advise on the appropriate dose for your circumstances.

For treatment of established AMS, Diamox may be used at higher doses alongside immediate descent — descent remains the definitive treatment. This page does not constitute prescribing guidance; all dosing decisions must be made by a qualified medical professional.

Biverkningar

Vanliga biverkningar (pharmacological, not allergic)

• Increased urination: Diamox is a mild diuretic. Adequate hydration is important.
• Paraesthesia: Tingling or numbness in the fingers, toes, and around the mouth. This is the most commonly reported side effect and is harmless but can be uncomfortable.
• Altered taste of carbonated drinks: Fizzy drinks may taste flat or unpleasant.
• Fatigue: Some patients report mild tiredness.
• Nausea: Particularly at higher doses.

Mindre vanliga side effects

• Reduced appetite
• Headache (may overlap with altitude sickness symptoms)
• Blurred vision
• Rash

Serious but rare side effects

• Severe allergic reactions (including Stevens-Johnson syndrome): Patients with sulfonamide hypersensitivity are at higher risk.
• Haematological changes: Including rare cases of aplastic anaemia and thrombocytopenia.
• Electrolyte disturbances: Particularly low potassium (hypokalaemia) with prolonged use.

Diamox jämfört med alternativ altitude sickness strategies

Approach	Type	Mechanism	Notes
Diamox (Acetazolamide)	Pharmacological	Stimulates breathing, accelerates acclimatisation	Best evidence base for AMS prevention
Gradual ascent	Non-pharmacological	Natural acclimatisation	Most effective strategy where time permits
Dexamethasone	Pharmacological (steroid)	Reduces cerebral oedema	Used for treatment of HACE, not routine prevention
Supplemental oxygen	Non-pharmacological	Raises blood oxygen	Used at altitude camps; impractical for most trekkers
Ibuprofen	Pharmacological	Reduces AMS-associated headache	Limited evidence for prevention; used for symptom relief

Hur får man Diamox online i Europa

Diamox (Acetazolamide) is a receptbelagt läkemedel in most EU-medlemsländer. Prescrivia operates as a technology intermediary — we do not prescribe medicines, employ doctors, or sell medicines. Our platform connects patients with independent EU-registered doctors who can conduct online travel health assessments.

The process is as follows:

1. Complete a travel health assessment: Provide details about your planned altitude, ascent schedule, travel dates, and full medical history.
2. Läkarbedömning: An independent EU-registered doctor reviews your assessment. If Diamox is clinically appropriate, they may issue a prescription.
3. Recept och leverans: If a prescription is issued, it is forwarded to a licensed EU pharmacy partner for dispensing and delivery.

Important: Prescrivia garanterar inte that a prescription will be issued. All prescribing decisions are made independently by qualified medical professionals based on your individual clinical circumstances.

Viktig säkerhetsinformation

Do not take Diamox if you:

• Have a known allergy to sulfonamides, sulfa drugs, or Acetazolamide
• Have severe liver or kidney disease
• Have Addison’s disease or adrenal insufficiency
• Have low blood sodium or potassium (hyponatraemia or hypokalaemia)
• Are in the first trimester of pregnancy

Berätta för din läkare if you:

• Have kidney stones (Diamox increases the risk)
• Are taking other diuretics, aspirin, or lithium
• Have diabetes (Diamox may affect blood glucose)
• Are breastfeeding

Descent is always the definitive treatment: If symptoms of altitude sickness are severe or worsening, the most important action is immediate descent to a lower altitude. Diamox is an adjunct, not a substitute for descent in serious cases.

Källor

Medical information on this page is based on the following sources:

• Världshälsoorganisationen (WHO). International Travel and Health. who.int
• Luks AM, et al. Wilderness Medical Society Clinical Practice Guidelines for the Prevention and Treatment of Acute Altitude Illness: 2019 Update. Wilderness Environ Med. 2019.
• Europeiska läkemedelsmyndigheten (EMA). Product information for Acetazolamide-containing medicines. ema.europa.eu
• Bartsch P, Swenson ER. Acute High-Altitude Illnesses. N Engl J Med. 2013;368:2294-2302.

This content is provided for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before travelling to high altitude.