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

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Brief Title

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

Official Title

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

Brief Summary

      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.

Study Phase

Phase 4

Study Type


Primary Outcome

Diagnosis of acute mountain sickness

Secondary Outcome

 Blood oxygen saturation


Acute Mountain Sickness



Study Arms / Comparison Groups



* Includes publications given by the data provider as well as publications identified by National Clinical Trials Identifier (NCT ID) in Medline.

Recruitment Information

Recruitment Status


Estimated Enrollment


Start Date

August 2011

Completion Date

October 2011

Primary Completion Date

October 2011

Eligibility Criteria

        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




18 Years - 65 Years

Accepts Healthy Volunteers

Accepts Healthy Volunteers


Buddha Basnyat, MD PhD, , 

Location Countries


Location Countries


Administrative Informations



Organization ID


Responsible Party


Study Sponsor

Oxford University Clinical Research Unit, Vietnam


 University of Oxford

Study Sponsor

Buddha Basnyat, MD PhD, Principal Investigator, University of Oxford

Verification Date

June 2013