Still, both a study author and one altitude expert not involved in the research said the approach won't help all travelers and climbers -- and isn't necessarily any better than taking prescription altitude-sickness drugs.

Even with ibuprofen, "there are still a lot of people who do have symptoms," said Robert Roach, head of the Altitude Research Center at the University of Colorado Denver School of Medicine.

Because the body's response to high altitudes varies person-by-person, there may be some people who do better with ibuprofen than with prescription drugs, including acetazolamide -- which increases the amount of oxygen in the blood -- and the steroid dexamethasone, he said.

But the opposite is also true.

"There are for sure going to be some people where ibuprofen doesn't do much," Roach told Reuters Health.

Research has suggested ibuprofen, marketed as Advil, among other brand names, helps relieve symptoms in people who already have altitude sickness -- which typically feels like a hangover, according to Roach, who wasn't part of the study team.

Researchers wanted to see if the over-the-counter drug could prevent those symptoms before they started.

For the study, volunteers were driven and hiked a few miles from an altitude of about 4,000 feet to over 12,000 feet in the White Mountains of California during the summer of 2010. Half of them were given 600 milligrams of ibuprofen three times during the day, starting six hours before the ascent. The other half took a drug-free placebo pill.

Researchers asked the participants about their altitude-related symptoms, including headaches, dizziness and nausea after they finished their trip and again in the morning after a night spent at altitude.

Out of the 86 participants in the study, 43 percent of those given ibuprofen reported symptoms of altitude sickness, compared to 69 percent of those on the placebo pills instead.

Eight of the volunteers had symptoms serious enough to warrant treatment -- six who had taken ibuprofen and two in the comparison group, the research team reported in the Annals of Emergency Medicine.

Dr. Jeffrey Gertsch from the University of California, San Diego School of Medicine and his colleagues calculated that four people would need to take ibuprofen before and during their high-altitude trip to prevent one from getting sick.

FALSE SENSE OF SECURITY?

Gertsch said one big question his team's study can't answer is whether ibuprofen is just easing altitude symptoms by providing pain relief or if it's really getting at the underlying causes of those symptoms, including inflammation and changes in blood vessels.

If it's only easing pain, he said, that could actually be worrisome for climbers.

"You could have a false sense of security… and get yourself into real trouble" at higher altitudes with low oxygen, Gertsch told Reuters Health.

Researchers will need to find objective ways to measure altitude sickness, besides patients' perceived pain and nausea, to try to answer that question, he added.

The researchers agreed that ibuprofen is an option for people who'd rather not take prescription drugs, which may cause side effects. Acetazolamide comes with a risk of nausea and fatigue -- symptoms of altitude sickness itself -- and dexamethasone may raise blood sugar levels and disturb sleep. And ibuprofen costs pennies per pill.

"People would be welcome to try it… and see how it works for them," Roach said -- assuming they realize ibuprofen can also come with side effects, including stomach problems.

"If people want to use this to prevent altitude sickness, I'm not going to say that's bad, they just need to be very careful," Gertsch added.

When it comes to high-altitude climbing, he said, "there is no substitute for careful planning, which is staged ascent, just going slow."

SOURCE: bit.ly/GU2x46 Annals of Emergency Medicine, online March 20, 2012.

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