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Effect of Acetazolamide on Maximal Exercise Performance in Lowlanders Older Than 40 Years at Altitude

Phase 4
Completed
Conditions
Altitude Hypoxia
Interventions
Drug: Placebo oral capsule
Registration Number
NCT03536455
Lead Sponsor
University of Zurich
Brief Summary

Randomized, placebo controlled trial evaluating the effect of acetazolamide on maximal exercise performance in lowlanders older than 40 years travelling from 760 m to 3'100 m.

Detailed Description

This is a randomized, placebo-controlled, double-blind parallel trial evaluating the effect of acetazolamide intake on the maximal exercise performance in lowlanders older than 40 years travelling to altitude. Participants living in the Bishkek area, Kyrgyzstan (760m), will be transferred by car within 4h to the Tuja Ashu high altitude clinic (3'100 m), and stay there for 2 days. Acetazolamide 375mg/day (or placebo), will be administered before departure at 760 m and during the stay at altitude. Outcomes will be assessed during the stay at 3'100 m.

An interim analysis will be carried out when 80 participants will have completed the study or after the first year. The Peto's method will be used and the trial will be stopped when pre-specified futility boundaries were crossed.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
92
Inclusion Criteria
  • Healthy men and women, age 40-75 yrs, without any disease and need of medication.
  • Born, raised and currently living at low altitude (<800m).
  • Written informed consent.
  • Kyrgyz ethnicity
Exclusion Criteria
  • Any active respiratory, cardiovascular or other disease requiring regular treatment or being otherwise relevant for tolerance of hypoxia or altitude exposure.
  • Any condition that may interfere with protocol compliance including current heavy smoking (>20 cigarettes per day or >20 pack-years with active smoking during the last 10 years), regular use of alcohol.
  • Allergy to acetazolamide and other sulfonamides.

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
ACETAZOLAMIDE oral capsuleACETAZOLAMIDE oral capsuleAcetazolamide 375mg/day (capsule @125 mg: 1 in the morning, 2 in the evening), orally. Medication starts 24 hours before ascent to 3'100m until the morning after the second night at 3'100m
PLACEBO oral capsulePlacebo oral capsulePlacebo (capsules identically looking as acetazolamide capsules: 1 in the morning, 2 in the evening), orally. Medication starts 24 hours before ascent to 3'100m until the morning after the second night at 3'100m
Primary Outcome Measures
NameTimeMethod
Change in maximal power output during exerciseDay 1 at 760m and day 1 at 3'100m

Difference in altitude-induced change in maximal power output between acetazolamide and placebo group.

Secondary Outcome Measures
NameTimeMethod
Change in muscle tissue oxygenation during exerciseDay 1 at 760m and day 1 at 3'100m

Difference in altitude-induced change in muscular tissue oxygenation between acetazolamide and placebo, measured by near-infrared spectroscopy during cycle spiroergometry

Change in peak oxygen uptake during exerciseDay 1 at 760m and day 1 at 3'100m

Difference in altitude-induced change in peak oxygen uptake between acetazolamide and placebo group.

Change in arterial blood gasses at rest and peak exerciseDay 1 at 760m and day 1 at 3'100m

Difference in altitude-induced change in arterial blood gases between acetazolamide and placebo measured before and at peak exercise.

Change in cerebral tissue oxygenation during exerciseDay 1 at 760m and day 1 at 3'100m

Difference in altitude-induced change in cerebral tissue oxygenation between acetazolamide and placebo, measured by near-infrared spectroscopy during cycle spiroergometry

Trial Locations

Locations (1)

National Center of Cardiology and Internal Medicine

🇰🇬

Bishkek, Kyrgyzstan

National Center of Cardiology and Internal Medicine
🇰🇬Bishkek, Kyrgyzstan

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