Acetazolamide, a drug commonly used to prevent acute mountain sickness, may reduce symptoms for some people who use it, a review of studies indicates.
However, herbal supplements were not effective treatments for the condition, found the researchers from Indiana University School of Medicine.
Acute mountain sickness, also called altitude sickness, "feels exactly like a hangover but can last a day or two," Dr Peter Hackett, director of the Institute for Altitude Medicine in Telluride, Colorado told Reuters Health.
According to Hackett, upon arriving to Colorado mountain ski resorts, as many as 40% of tourists experience symptoms of headache, nausea and fatigue.
Aim to determine effective meds
"Our aim was to determine which medications or supplements most effectively prevented acute mountain sickness with the fewest side effects in adults travelling to high elevations," lead author Dr Rawle Seupaul told Reuters Health.
Seupaul and his team reviewed seven studies that compared several drugs and supplements for treating the symptoms of acute mountain sickness, and published the review this month in the Annals of Emergency Medicine.
Three trials studied acetazolamide, marketed as Diamox and approved by the Food and Drug Administration to prevent acute mountain sickness.
Acetazolamide speeds up the body's natural acclimation to altitude by stimulating breathing, which in turn increases the amount of oxygen in the blood.
Acetazolamide symptoms include numbness
The other studies looked at the effects of gabapentin (marketed as Neurontin), used to treat seizures and chronic pain, sumatriptan (Imitrex), used to treat migraine headaches, antioxidants, magnesium and Ginkgo biloba.
All trials were published after 2000 and had at least 50 participants.
Acetazolamide, which costs about R50 per 500 milligram pill, prevented symptoms in as many as one of every three people taking the drug, at doses ranging from 125 milligrams twice per day to 750 milligrams once a day.
Lower doses, though slightly less effective, were also associated with fewer side effects. The most common side effects reported by people using acetazolamide included numbness and tingling, or a pins-and-needles sensation, frequent urination and an alteration in the way things taste.
Enthusiasm in herbs and abtioxidants
Though gabapentin and sumatriptan are not commonly prescribed for acute mountain sickness, they each showed benefit in a single trial for one of every six people treated with gabapentin and one of every four people using sumatriptan.
People using antioxidants, magnesium and Ginkgo biloba experienced acute mountain sickness at similar rates as those given a placebo.
"There's a lot of enthusiasm for antioxidants and herbals, but no evidence to back it up," said Seupaul.
The review did not include trials studying the use of dexamethasone, a medication given to treat severe cases of altitude sickness, but rarely prescribed preventatively, according to Hackett.
Sickness clears up after two days
Acute mountain sickness occurs most frequently in people who travel rapidly to elevations above 8,000 feet. Anyone can get acute mountain sickness, although some people appear more genetically prone to it.
A slow ascent to altitude is considered the best way to prevent acute mountain sickness, but often isn't an option for people flying directly from sea level to a mountain resort.
It's helpful to stay overnight at an intermediate altitude if possible, suggested Hackett, for example staying a night in Denver before travelling to your resort.
It's also a good idea to avoid alcohol the first night you arrive and take care not to overexert yourself the first day, he said.
While acute mountain sickness can leave you feeling crummy, it usually clears up within a day or two on its own. Ibuprofen, rest and drinking plenty of water can help said Dr Hackett, but do seek medical care if you are short of breath, you feel dizzy or your headache worsens.
(Reuters Health, December 2011)