Acetazolamide for the Prevention of High Altitude Illness: a Comparison of Dosing

NCT ID: NCT01993667

Last Updated: 2019-01-29

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: PHASE4
• Total Enrollment: 130 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2012-03-31
• Study Completion Date: 2016-11-30

Brief Summary

This is a phase 4, randomized, double-blinded interventional trial comparing alternative doses of Acetazolamide for the prevention of High Altitude Illness.

Detailed Description

Acetazolamide, or Diamox, is the standard medical prophylaxis agent for high altitude illness. The medication is effective in preventing acute mountain sickness (AMS), high altitude pulmonary edema (HAPE), and high altitude cerebral edema (HACE). Its mechanism is via inhibition of the carbonic anhydrase enzyme which counteracts the respiratory alkalosis which occurs during ascent to altitude. It facilitates the excretion of bicarbonate in the urine. As a result, acetazolamide hastens acclimatization and helps prevent high altitude disorders.

Current recommended dosing is 125 mg, orally twice daily, started 24 hours prior to ascending in elevation. Side effects include tingling of the fingers and toes and perioral numbness which may be erroneously interpreted as stroke symptoms. Since acetazolamide is a mild diuretic, frequent micturition may occur leading to interruption of daytime activities as well as broken sleep. These effects can affect safety at high altitude. Acetazolamide is normally discontinued 2 days after the user has reached their highest elevation or a plateau in elevation.

A lower dose may be just as effective in preventing high altitude illnesses while preventing the disconcerting side effects resulting from its use. A smaller dose has not been studied, however. We will compare the common dose of 125 mg twice daily with a lower dose of 62.5 mg twice daily.

Conditions

Prophylaxis of Acute Mountain Sickness

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: DOUBLE

Study Groups

Acetazolamide normal dose

Experimental : Acetazolamide 125 mg twice daily

Group Type: ACTIVE_COMPARATOR

Normal Dose Acetazolamide

Intervention Type: DRUG

Administration of normal dose acetazolamide

Acetazolamide low dose

Experimental: Acetazolamide 62.5 mg twice daily

Group Type: EXPERIMENTAL

Low Dose Acetazolamide

Intervention Type: DRUG

Administration of low dose acetazolamide

Interventions

Low Dose Acetazolamide

Administration of low dose acetazolamide

Intervention Type: DRUG

Normal Dose Acetazolamide

Administration of normal dose acetazolamide

Intervention Type: DRUG

Other Intervention Names

Diamox; Diamox

Eligibility Criteria

Inclusion Criteria

• 18 years or older
• English or Indian speaking
• Mountaineers or trekkers who plan to climb Mt. McKinley or trek to Base Camp on Mt. Everest

Exclusion Criteria

• Low sodium and/potassium blood serum levels
• Kidney disease or dysfunction
• Liver disease, dysfunction, or cirrhosis
• Suprarenal gland failure or dysfunction
• Hyperchloremic acidosis
• Angle-closure glaucoma
• Taking high dose aspirin (over 325 mg/day)
• Any reaction to sulfa drugs or acetazolamide
• Pregnant or lactating women

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

University of Utah

OTHER

Sponsor Role: lead

Responsible Party

Scott McIntosh

Associate Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

McIntosh Scott, MD

Role: PRINCIPAL_INVESTIGATOR

University of Utah

Locations

University of Utah Health Sciences Center

Salt Lake City, Utah, United States

Countries

United States

Other Identifiers

50402

Identifier Type: -

Identifier Source: org_study_id