Acetazolamide is used to prevent and reduce the symptoms of altitude sickness. This medication can decrease headache, tiredness, nausea, dizziness, and shortness of breath that can occur when you climb quickly to high altitudes (generally above 10,000 feet/3,048 meters). It is particularly useful in situations when you cannot make a slow ascent. The best ways to prevent altitude sickness are climbing slowly, stopping for 24 hours during the climb to allow the body to adjust to the new height, and taking it easy the first 1 to 2 days.
This medication is also used with other medications to treat high pressure inside the eye due to certain types of glaucoma. Acetazolamide belongs to a class of drugs known as carbonic anhydrase inhibitors. It works by decreasing the production of fluid inside the eye. It is also used to decrease a buildup of body fluids (edema) caused by heart failure or certain medications. Acetazolamide can work less well over time, so it is usually used only for a short period.
It has also been used with other medications to treat certain types of seizures (petit mal and unlocalized seizures).
This section contains uses of this drug that are not listed in the approved professional labeling for the drug but that may be prescribed by your health care professional. Use this drug for a condition that is listed in this section only if it has been so prescribed by your health care professional.
This drug may also be used for a certain condition causing a serious increase in pressure inside the skull (intracranial hypertension).
How to Use This Medication
If you are taking the tablets, take this medication by mouth as directed by your doctor, usually 1 to 4 times daily. If you are taking the long-acting capsules, take this medication by mouth as directed by your doctor, usually 1 or 2 times daily. Swallow the long-acting capsules whole. Do not open, break, or chew the capsules. Doing so can destroy the long action of the drug and may increase side effects.
Acetazolamide may be taken with or without food. Drink plenty of fluids unless otherwise directed by your doctor. The dosage is based on your medical condition and response to treatment.
To prevent altitude sickness, start taking acetazolamide 1 to 2 days before you start to climb. Continue taking it while you are climbing and for at least 48 hours after you have reached your final altitude. You may need to continue taking this medication while staying at the high altitude to control your symptoms. If you develop severe altitude sickness, it is important that you climb down as quickly as possible. Acetazolamide will not protect you from the serious effects of severe altitude sickness. (See also Precautions.)
If you are taking this drug for another condition (such as glaucoma, seizures), use this medication regularly as directed to get the most benefit from it. To help you remember, take it at the same time(s) each day. Taking your last dose in the early evening will help prevent you from having to get up in the middle of the night to urinate. Consult your doctor or pharmacist if you have questions about your dosing schedule.
Do not increase your dose or use this drug more often or for longer than prescribed. Your condition will not improve any faster, and your risk of side effects will increase.
When used for an extended period, this medication may not work as well and may require different dosing. Your doctor will be monitoring your condition. Tell your doctor if your condition does not improve or if it worsens (for example, you have more frequent seizures).
This drug may reduce the potassium levels in your blood. Your doctor may recommend that you eat foods rich in potassium (such as bananas or orange juice) while you are taking this medication. Your doctor may also prescribe a potassium supplement for you to take during treatment. Consult your doctor for more information.
Tell your doctor if your condition lasts or gets worse.