A Trial of Acetazolamide Versus Placebo in Preventing Mountain Sickness During Rapid Ascent

Double Blind, Placebo Controlled Randomised Trial of Acetazolamide Versus Placebo in the Prevention of Acute Mountain Sickness During Rapid Ascent

Acute mountain sickness is a common ailment in people venturing over 2500 m altitude. Pilgrims to high altitudes are at an added risk since they are unaware and they gain height faster than the recommendations. Acetazolamide is the standard treatment and prophylaxis of acute mountain sickness. There are no randomized controlled trials that have studied protective effects of Acetazolamide in rapid ascent, and there are few conflicting studies regarding this matter.

This study is a randomized, double blinded, placebo controlled trial of Acetazolamide versus placebo in 380 healthy individuals travelling to Gosaikunda Lake of Nepal in rates of ascent that are faster than the recommendations. Acetazolamide 125 mg twice daily and a placebo will be randomly assigned for 3 days and participants will be assessed at 3 stations.

This study will undertake to establish the role of Acetazolamide in Rapid Ascent and will be the first RCT done in this issue.

The investigators hypothesize that Acetazolamide 125mg twice daily given before rapid ascent to high altitude in Nepalese pilgrims will not be superior to placebo in decreasing both the incidence and severity of acute mountain sickness.

Inclusion Criteria:

• Nepalese national
• Aged 18 to 65
• Travelling directly from Dhunche to Gosainkunda
• Rapid ascent as defined by ascent within 3 days

Exclusion Criteria:

• Use of any drugs for the prevention of altitude sickness or headache
• Current illness
• Current altitude sickness (more than one mild symptom on the Lake Louise Questionnaire (LLQ), or oxygen saturation less than 75%
• Known to be pregnant or cannot exclude the possibility of being pregnant, or have missed menses by over 7 days
• One night within the last 30 days spent at an altitude of 4500 metres or above
• Residents of altitude more than 2500m
• A known drug allergy to sulfonamides.
• Treatment with any of the following in the last 2 days: acetazolamide (Diamox®), steroids (dexamethasone/decadron, prednisone), theophylline or diuretics (Lasix®), ibuprofen/motrin, naprosyn/naproxen, aspirin or acetaminophen.
• Any serious intracranial abnormalities such as history of brain tumours or pseudotumour cerebri
• Known severe uncontrolled headache syndrome
• Diagnosed renal function impairment, diabetes, cirrhosis of liver or liver dysfunction