Effect of Acetazolamide on Acute Mountain Sickness in Women Compared to Men

HighCycle Study: Effect of Acetazolamide on Acute Mountain Sickness in Women Compared to Men: A Randomized, Placebo-Controlled, Double-Blind Parallel Trial

Phase 4 Interventional University of Zurich · NCT06499727

This study tests if acetazolamide can help prevent acute mountain sickness in women compared to men when they are exposed to high altitudes.

Quick facts

PhasePhase 4
Study typeInterventional
Enrollment270 (estimated)
Ages18 Years to 44 Years
SexAll
SponsorUniversity of Zurich Academic / other
Locations1 site (Bishkek)
Trial IDNCT06499727 on ClinicalTrials.gov

What this trial studies

This study investigates the effectiveness of acetazolamide in preventing acute mountain sickness (AMS) among healthy men and women, with a specific focus on the differences between sexes. It aims to address the underrepresentation of women in altitude studies by controlling for factors such as sex hormones and menstrual cycle phases. Participants will be given either acetazolamide or a placebo while exposed to high altitudes, and their symptoms of AMS will be monitored. The study seeks to provide a clearer understanding of how gender influences susceptibility to AMS and the efficacy of preventive treatments.

Who should consider this trial

Good fit: Ideal candidates for this study are healthy, non-smoking men and women aged 18-44 who live at low altitudes and are premenopausal with regular menstrual cycles.

Not a fit: Patients who are pregnant, nursing, or using certain forms of hormonal contraception may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to improved prevention strategies for acute mountain sickness, particularly for women.

How similar studies have performed: While studies on acute mountain sickness exist, this specific focus on gender differences and hormonal influences is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Healthy, non-smoking men and women, age 18-44 years, without any disease and need of regular medication (including oral contraceptives).
* BMI \>18 kg/m2 and \<30 kg/m2
* Born, raised and currently living at altitudes \<1000 m
* Written informed consent
* Premenopausal women with an eumenorrheic cycle

Exclusion Criteria:

* Other types of contraceptvies (contraceptives (hormonal intrauterine device, vaginal ring, subcutaneous injections or implants, among others)
* Pregnancy or nursing
* Anaemic (haemoglobin concentration \<10g/dl)
* Any altitude trip \<4 weks before the study
* Allergy to acetazolamide and other sulfonamides

Where this trial is running

Bishkek

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Acute Mountain SicknessWomenHypoxiaPreventionAcetazolamideAltitude
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.