Altitude Sickness and Side Effects of Diamox

By Courtney S. Ries

Travelers who take on popular treks like the Annapurna Circuit, Mt. Kilimanjaro and Machu Picchu/Inca Trail should be well versed in altitude sickness before their trip. Altitude sickness, also called mountain sickness, is the name given to the negative effects of altitude experienced by those at high elevation. Anyone can get altitude sickness, no matter the age or level of fitness. Trekkers should be on the lookout for symptoms anywhere above 8,000 feet. They can show up 8-36 hours after ascent and include:

Headache
Nausea or vomiting
Insomnia
Lack of appetite

At its mildest form, altitude sickness is referred to as acute altitude sickness. Symptoms of illness usually disappear after descending around 3000 feet. People who show signs of altitude sickness should NOT continue to climb. Further ascent can lead to HAPE (High Altitude Pulmonary Edema) or HACE (High Altitude Cerebral Edema), both of which have been known to result in death.

Symptoms of HAPE and HACE include:

Difficulty breathing
Lethargy
Confusion
Unsteady gait

The best way to avoid altitude sickness is to take as much time as possible to allow yourself to acclimatize. According to this excellent article, when you climb above 10,000 feet (3,000 meters), your sleeping elevation should not increase any more than 1,000 feet (300 meters) per night. For every 3000 feet (1000 meters), spend a second night at the same elevation.

There are a few other things you can do to help your body cope with the lower levels of oxygen - avoid alcohol, drink plenty of water and make sure you are keeping your body properly fueled with light meals. Many trekkers also give themselves a boost with prescriptions such as Diamox.

Traditionally, Diamox has been prescribed to treat glaucoma, epilepsy, and fluid retention. However, researchers also discovered that it can be used to treat the symptoms of mountain sickness, especially for those with a rapid ascent. Because many climbers who attempt to summit Kili are doing so in as little time as possible, it is a common prescription on the mountain.

The medicine is usually taken twice a day, 12 hours apart. Prescribed treatment should start 24 to 48 hours before ascent, however, many people in my group did not start taking the medicine until they started to feel ill. If you decide to hold off on treatment, know that it requires time to get into your bloodstream, so you are taking a chance of not feeling well soon enough. I began taking Diamox 24 hours before the start of my climb up Mt. Kilimanjaro. My dosage was 500 mg. twice a day, although others were as low as 175 mg. Medical websites suggest 500-1,000 mg. a day when used for altitude sickness.

Please note that you cannot take high doses of aspirin with Diamox, and that you must descend if you experience symptoms of acute altitude sickness. Diamox does not ensure that you will be able to appropriately adjust to altitude - it is only an aid that allows your body to acclimatize faster.

Diamox has a number of side effects, the most common of which are listed below. Most issues occur within the first few days of taking the drug. I experienced most of them.

Diamox Side Effects

Frequent Urination: Like coffee, Diamox is a diuretic. As it is prescribed for those with fluid retention, it's no wonder that you have to go to the bathroom every 30 minutes.

Tingly hands/feet (parethesias): Occasionally, my hands would get the 'pins and needles' feeling. Even more disquieting were the 'hot spots' that I felt on my feet.

Loss of Appetite: I was always hungry, but others had an strong disinterest in food.

Taste Alteration: Sodas and other foods can taste differently due to Diamox. I did not experience this.

Internal Distress: This includes nausea, vomiting and diarrhea. These are also side effects of altitude sickness, so it can be difficult to pinpoint the culprit.

Drowsiness and Confusion: Perhaps the oddest side affect I experienced - on the first day of the climb, I felt, at points, as if I was hiking after having a few drinks. Things seemed out of place and it would have been very difficult to continue climbing had this side effect endured.

When climbing to high altitudes, the most important thing to remember is that no climb is worth compromising your life. Watch for signs of altitude sickness, ascend slowly and enjoy the trek!