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

Summary

Millions of people travel to high altitude for work or leisure activities and are exposed to reduced inspiratory oxygen partial pressure and hypoxemia that may lead to altitude illness, among which the most common form is acute mountain sickness (AMS). The main AMS symptoms are headache, malaise, weakness, and fatigue. Prospective studies have shown that 20-60% of newcomers at 2500-4000m develop AMS requiring them to take medications, while, at very high altitudes, AMS may progress to high altitude cerebral oedema. Whether women are more susceptible to AMS remains insufficiently understood since no prospective study controlled for sex hormones, use of hormone contraception or assessed menstrual cycle phase (MCP) at altitude. Therefore, women remain underrepresented and poorly characterized in high altitude studies. In addition, the efficacy and safety of 250 mg/day acetazolamide, the standard recommendation for AMS prevention, has never been compared between sexes, although, women have presumably higher acetazolamide plasma concentration due to lower blood volume. Given the known dose-dependent preventive but also side effects of acetazolamide and equal proportion of women and men among mountain travellers, there is an urgent need to conclusively quantify the efficacy and safety of pre-ventive acetazolamide therapy against AMS in women compared to men.

Conditions

• Acute Mountain Sickness

Interventions

DRUG

Acetazolamide

Administration of 1x125mg acetazolamide in the morning, 1x125mg in the evening, starting 24 hours before departure to 3600 m.

DRUG

Placebo

Administration of equally looking placebo capsules in the morning and in the evening, starting 24 hours before departure to 3600 m.

Sponsors & Collaborators

• National Center of Cardiology and Internal Medicine named after academician M.Mirrakhimov

  collaborator OTHER_GOV

• University Hospital Heidelberg

  collaborator OTHER

• Laboratoire des Adaptations Métaboliques à l'Exercice en conditions Physiologiques et Pathologiques

  collaborator OTHER

• University of Zurich

  lead OTHER

Principal Investigators

• Michael Furian, Prof. Dr. · University of Zurich

• Talant Sooronbaev, Prof. Dr. · National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyzstan

Study Design

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

QUADRUPLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

44 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2024-07-15

Primary Completion

2025-08-31

Completion

2025-08-31

Countries

• Kyrgyzstan

Study Locations