Acetazolamide for the Prevention of High Altitude Illness: a Comparison of Dosing
Information source: University of Utah
ClinicalTrials.gov processed this data on August 20, 2015
Link to the current ClinicalTrials.gov record.
Condition(s) targeted: Prophylaxis of Acute Mountain Sickness
Intervention: Acetazolamide (Drug)
Phase: Phase 4
Status: Recruiting
Sponsored by: University of Utah Official(s) and/or principal investigator(s):
McIntosh Scott, MD, Principal Investigator, Affiliation: University of Utah
Summary
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.
Clinical Details
Official title: Acetazolamide for the Prevention of High Altitude Illness: a Comparison of Dosing
Study design: Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Investigator), Primary Purpose: Treatment
Primary outcome: Prevention of acute mountain sickness as measured by the Lake Louise Score
Secondary outcome: Side effect profile of acetazolamide
Eligibility
Minimum age: 18 Years.
Maximum age: N/A.
Gender(s): Both.
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
Locations and Contacts
University of Utah Health Sciences Center, Salt Lake City, Utah 84132, United States; Recruiting
Scott McIntosh, MD, Email: scott.mcintosh@hsc.utah.edu
Scott McIntosh, MD, Principal Investigator
Additional Information
Starting date: March 2012
Last updated: May 26, 2015
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