Prophylaxis of Acute Mountain SicknessPhase 4NCT01993667
Acetazolamide for the Prevention of High Altitude Illness: a Comparison of Dosing
A Phase 4 study testing Low Dose Acetazolamide and Normal Dose Acetazolamide in people with Prophylaxis of Acute Mountain Sickness, run by University of Utah at 1 site in United States.
Trial summary
This is a phase 4, randomized, double-blinded interventional trial comparing alternative doses of Acetazolamide for the prevention of High Altitude Illness. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Prophylaxis of Acute Mountain Sickness
- What is being tested?
- Low Dose Acetazolamide and Normal Dose Acetazolamide
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 130 participants
- Where
- 1 siteUnited States
- Study dates
- Mar 2012to Nov 2016
- Phase
- Phase 4
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- 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
Who cannot join
- 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
Show all 9Show fewer
- Taking high dose aspirin (over 325 mg/day)
- Any reaction to sulfa drugs or acetazolamide
- Pregnant or lactating women
Trial locations and contacts
1 site in 1 country.
United States1 site
University of Utah Health Sciences Center
Salt Lake City, Utah, 84132
About this study
This is a phase 4, randomized, double-blinded interventional trial comparing alternative doses of Acetazolamide for the prevention of High Altitude Illness.
Read the 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
- Being tested
- Low Dose Acetazolamide, Normal Dose Acetazolamide
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Low Dose AcetazolamideDrug
Also called Diamox
Administration of low dose acetazolamide
Normal Dose AcetazolamideDrug
Also called Diamox
Administration of normal dose acetazolamide
| Study group | Role | What they receive |
|---|---|---|
| Acetazolamide normal dose | Active comparator | Experimental : Acetazolamide 125 mg twice daily Receives: Drug: Normal Dose Acetazolamide |
| Acetazolamide low dose | Experimental | Experimental: Acetazolamide 62.5 mg twice daily Receives: Drug: Low Dose Acetazolamide |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of Participants With Acute Mountain Sickness as Measured by the Lake Louise Score
Lake Louise Score, A total score of 3 to 5 indicates mild AMS. A score of 6 or more signifies severe AMS. Minimum value - 0, Maximum = 15
Measured: 12 days
Secondary outcomes (1)
Number of Participants With Side Effects
The typical side effects of acetazolamide will be measured daily (paresthesias of fingers and toes, change in urination frequency, and change in taste of beverages).
The side effect questionnaire included the following questions: In the past 12 h, have you experienced the following symptoms: Tingling of toes? Tingling of fingers? Increase in urination? Taste change of beverages? Symptoms were self-reported and rated on a 0-5 scale (0=none, 5=maximum)
Measured: 12 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Nov 2013 (estimated)
- Study startMar 2012
- Primary completionNov 2016
- Study completionNov 2016
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for Prophylaxis of Acute Mountain SicknessStudies of the same condition, open and under way.
- More trials run by University of UtahThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 130 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Utah
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Scott McIntosh, University of Utah
- Investigators
- McIntosh Scott, MD, Principal investigator, University of Utah
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01993667
- Sponsor's protocol ID
- 50402
- Status last verified
- Jan 2019
- First submitted
- 12 Nov 2013
- Last updated
- 29 Jan 2019
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 29 Jan 2019. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Acetazolamide for the Prevention of High Altitude Illness: a Comparison of Dosing
- ClinicalTrials.gov ID
- NCT01993667
- Acronym / sponsor ID
- 50402
- Conditions
- Prophylaxis of Acute Mountain Sickness
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 130 participants (actual)
- Lead sponsor
- University of UtahUniversity, hospital or other
- Study start
- Mar 2012
- Primary completion
- Nov 2016 (actual)
- Study completion
- Nov 2016 (actual)
- First posted
- 25 Nov 2013 (estimated)
- Results
- Posted 29 Jan 2019
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Acetazolamide normal dose | Active comparator | Drug: Normal Dose AcetazolamideExperimental : Acetazolamide 125 mg twice daily |
| Acetazolamide low dose | Experimental | Drug: Low Dose AcetazolamideExperimental: Acetazolamide 62.5 mg twice daily |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- 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
Key exclusion criteria (9 listed)
- Low sodium and/potassium blood serum levels
- Kidney disease or dysfunction
- Liver disease, dysfunction, or cirrhosis
- Suprarenal gland failure or dysfunction
- Hyperchloremic acidosis
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Low Dose AcetazolamideAlso: DiamoxAdministration of low dose acetazolamide | Drug | Acetazolamide low dose |
| Normal Dose AcetazolamideAlso: DiamoxAdministration of normal dose acetazolamide | Drug | Acetazolamide normal dose |
Primary outcome
Number of Participants With Acute Mountain Sickness as Measured by the Lake Louise Score
Time frame: 12 days
Lake Louise Score, A total score of 3 to 5 indicates mild AMS. A score of 6 or more signifies severe AMS. Minimum value - 0, Maximum = 15
1 secondary outcome
Number of Participants With Side Effects
Time frame: 12 days
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 29 Jan 2019.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
Related trials for Prophylaxis of Acute Mountain Sickness
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
McIntosh Scott, MD principal investigator
University of Utah
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing Low Dose Acetazolamide and Normal Dose Acetazolamide in people with Prophylaxis of Acute Mountain Sickness, run by University of Utah at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 29 Jan 2019. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Yes. Results are posted in the registry (first posted 29 Jan 2019). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of Participants With Acute Mountain Sickness as Measured by the Lake Louise Score (time frame: 12 days). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 29 Jan 2019.