Sickness Evaluation at Altitude With Acetazolamide at Relative Dosages

2018-02-12 17:45:11 | BioPortfolio


This double blind randomized trial will compare acetazolamide taken the morning of ascent to acetazolamide taken the evening prior to ascent for the prevention of acute mountain sickness (AMS). The day of ascent dosing has not been studied as a powered primary outcome. The study population is hikers who are ascending at their own rate under their own power in a true hiking environment at the White Mountain Research Station, Owen Valley Lab (OVL) and Bancroft Station (BAR), Bancroft Peak, White Mountain, California


The specific aim of this study is to determine whether acetazolamide started the day-of ascent is inferior to the standard night before ascent dose of acetazolamide for the prevention of acute mountain sickness (AMS) in travelers in travelers to high altitude. Acetazolamide has been examined in over 200 high altitude studies over the past 50 years, and is the most commonly used drug for AMS prevention in the high mountains of Nepal, Western Europe, and Africa. Current Wilderness Medical Society Practice Guidelines recommend a 125mg dose of acetazolamide daily started the day or evening prior to ascent. However, day of ascent dosage has recently been found to be effective prophylaxis for severe AMS compared to placebo, but efficacy of day-of ascent dosage has not be confirmed versus standard acetazolamide dosage.

While acetazolamide is commonly used as an acclimatization aid, it is traditionally started the day or evening prior to ascent to theoretically optimize diuretic effect and compensatory respiratory changes. This timing may be impractical when rapid ascent is necessary, such as in search and rescue and military operations, or for the general recreationalists, trekkers, or climbers who do not have time to start prophylaxis prior to heading into the mountains. As there are an estimated 100 million recreationalists annually who ascend to high altitude around the world, innovation on optimal timing has a potentially large impact on traveler safety.

Acetazolamide has a time of onset between 60 - 90 minutes when taken as an immediate release tablet, with peak effect between 2 - 4 hours. With these pharmacokinetics in mind, we recently found that there was an observed robust protective effect of acetazolamide on severe AMS when taken the morning of ascent, and this was the first study to examine day-of dosing. This novel finding has not been otherwise investigated, and confirmation of this unique observation has the potential to increase acetazolamide'sits usage in "high risk" populations maximizing safety, while minimizing discomfort and poor sleep from pre-ascent nocturia., such as trekkers, skiers, climbers, and tactical missions requiring rapid ascents in the mountains of North America and Europe.

Study Design


Acute Mountain Sickness




Not yet recruiting


Stanford University

Results (where available)

View Results


Published on BioPortfolio: 2018-02-12T17:45:11-0500

Clinical Trials [235 Associated Clinical Trials listed on BioPortfolio]

Sickness Evaluation at Altitude With Acetazolamide at Relative Doses

The specific aim of this study is to evaluate whether acetazolamide 125mg daily is no worse than acetazolamide 250mg daily in decreasing the incidence of acute mountain sickness (AMS) in t...

Tadalafil and Acetazolamide Versus Acetazolamide in Acute Mountain Sickness Prevention

To evaluate the additive value of tadalafil given together with Diamox (acetazolamide) in preventing acute mountain sickness in travelers to high altitude areas.

Effect of Acetazolamide on Acute Mountain Sickness in Lowlanders Older Than 40 Years

Randomized, placebo controlled trial evaluating efficacy of acetazolamide in preventing acute mountain sickness in lowlanders older than 40 years travelling from 760 m to 3'100 m.

Controlled Hyperventilation as Prophylaxis for Acute Mountain Sickness

This study evaluates the safety and efficacy of the voluntary ventilatory response as prophylaxis for acute mountain sickness, measured by the Lake Louise Self-Report Score, comparing to a...

Altitude Sickness Prevention and Efficacy of Comparative Treatments

This study is designed to be the first to examine the novel drug budesonide for prevention of acute mountain sickness in comparison to acetazolamide and in the context of rapid ascent to h...

PubMed Articles [6130 Associated PubMed Articles listed on BioPortfolio]

Relationship of Activity Patterns to Acute Mountain Sickness in South Pole Workers.

This study aimed to evaluate the influence of physical activity on incidence of acute mountain sickness (AMS) by continuous activity monitoring in a free-living sample of South Pole workers over the i...

Mountain neurology.

Mountain climbers may develop specific illnesses that largely depend on the altitude reached and the rate of ascent. The popularity of travel to high altitude destinations, extreme tourist activities ...

Physiological Responses in Humans Acutely Exposed to High Altitude (3480 m): Minute Ventilation and Oxygenation Are Predictive for the Development of Acute Mountain Sickness.

Burtscher, Martin, Michael Philadelphy, Hannes Gatterer, Johannes Burtscher, Martin Faulhaber, Werner Nachbauer, and Rudolf Likar. Physiological responses in humans acutely exposed to high altitude (3...

Are Pre-ascent Low-Altitude Saliva Cortisol Levels Related to the Subsequent Acute Mountain Sickness Score? Observations from a Field Study.

The associations among cortisol levels, body water status, and acute mountain sickness (AMS) remain unclear. We investigated associations between AMS prevalence and severity with resting saliva cortis...

Swiss Mountain Guides: Medical Education, Knowledge, and Practice.

Mountain guides work daily in remote areas and high-altitude locations where specific hypoxia-related and common medical problems may occur. Arrival of rescue teams can be delayed, so mountain guides ...

Medical and Biotech [MESH] Definitions

Disorder caused by motion, as sea sickness, train sickness, car sickness, air sickness, or SPACE MOTION SICKNESS. It may include nausea, vomiting and dizziness.

A histamine H1 antagonist used in the treatment of motion sickness, vertigo, and nausea during pregnancy and radiation sickness.

Immune complex disease caused by the administration of foreign serum or serum proteins and characterized by fever, lymphadenopathy, arthralgia, and urticaria. When they are complexed to protein carriers, some drugs can also cause serum sickness when they act as haptens inducing antibody responses.

An acute febrile illness caused by RICKETTSIA RICKETTSII. It is transmitted to humans by bites of infected ticks and occurs only in North and South America. Characteristics include a sudden onset with headache and chills and fever lasting about two to three weeks. A cutaneous rash commonly appears on the extremities and trunk about the fourth day of illness.

An acute, often fatal disease caused by the ingestion of milk, milk products, or the flesh of cattle or sheep which have a disease known as trembles. It is marked by weakness, anorexia, vomiting, constipation, and sometimes muscular tremors. It is caused by poisoning by white snakeroot (Eupatorium rugosum) and the rayless goldenrod (Haplopappus heterophyllus). (From Dorland, 27th ed)

More From BioPortfolio on "Sickness Evaluation at Altitude With Acetazolamide at Relative Dosages"

Quick Search

Relevant Topics

Drug Discovery
Clinical Approvals Clinical Trials Drug Approvals Drug Delivery Drug Discovery Generics Drugs Prescription Drugs In the fields of medicine, biotechnology and pharmacology, drug discovery is the process by which drugs are dis...

Asthma COPD Cystic Fibrosis Pneumonia Pulmonary Medicine Respiratory Respiratory tract infections (RTIs) are any infection of the sinuses, throat, airways or lungs.  They're usually caused by viruses, but they can also ...

Searches Linking to this Trial