acetazolamide

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 drug is also used with other medications to treat a certain type of eye problem (open-angle glaucoma). Acetazolamide is a "water pill" (diuretic). It decreases the amount of fluid that can build up in the eye. It is also used to decrease a buildup of body fluids (edema) caused by congestive 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).

If you miss a dose, take it as soon as you remember. If it is near the time for your next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.

If you are taking the tablets, take this medication by mouth, usually 1 to 4 times daily or as directed by your doctor. If you are taking the long-acting capsules, take this medication by mouth, usually 1 or 2 times daily or as directed by your doctor. 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. Your dosage is based on your medical condition and response to therapy. 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 (e.g., 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 or decrease your dose or stop using this medication without first consulting your doctor. Some conditions may become worse when this drug is suddenly stopped. Your dose may need to be gradually decreased. 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 (e.g., more frequent seizures). This drug may reduce the potassium levels in your blood. Your doctor may recommend that you eat foods rich in potassium (e.g., 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.

Your healthcare professionals (e.g., doctor or pharmacist) may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop or change the dosage of any medicine before checking with them first. This drug should not be used with the following medications because very serious interactions may occur: cisapride, methenamine. If you are currently using either of these medications listed above, tell your doctor or pharmacist before starting acetazolamide. Before using this medication, tell your doctor or pharmacist of all prescription and nonprescription/herbal products you may use, especially: anticonvulsants (e.g., phenytoin, primidone, phenobarbital, topiramate, zonisamide), other diuretics similar to this medication (carbonic anhydrase inhibitors such as brinzolamide, dorzolamide), cyclosporine, digoxin, drugs for diabetes (e.g., glyburide, insulin), drugs that cause loss of potassium (e.g., diuretics such as furosemide, corticosteroids such as prednisone, amphotericin B), lithium, memantine, procainamide, quinidine, salicylates (e.g., aspirin, bismuth subsalicylate), sodium bicarbonate, stimulants (e.g., amphetamines, ephedrine), tricyclic antidepressants (e.g., amitriptyline). Check all prescription and nonprescription labels carefully since they may contain medications (e.g., anti-diarrhea drugs, pain relievers/fever reducers) similar to aspirin, which can cause serious side effects when taken with acetazolamide. Low-dose aspirin, as prescribed by your doctor for specific medical reasons such as heart attack or stroke prevention (usually at dosages of 81-325 milligrams per day), should be continued. Consult your doctor or pharmacist for more details. This medication may interfere with certain laboratory tests, possibly causing false test results. Make sure laboratory personnel and your doctor know you use this drug. This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist.

Your condition can cause complications in a medical emergency. For enrollment information call MedicAlert at 1-800-854-1166 (USA), or 1-800-668-1507 (Canada).

Do not change brands or dosage forms of this medication without consulting your doctor or pharmacist. Not all forms of this medication work the same way. Do not share this medication with others. Laboratory and/or medical tests (e.g., blood count, minerals such as potassium and sodium, liver function tests) may be performed from time to time to monitor your progress and check for side effects. Consult your doctor for more details.

If overdose is suspected, contact your local poison control center or emergency room immediately. US residents can call the US national poison hotline at 1-800-222-1222. Canadian residents should call their local poison control center directly.

Before taking acetazolamide, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details. This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist if you have: adrenal gland problems (e.g., Addison's disease), low blood levels of sodium or potassium, severe kidney disease, severe liver disease (e.g., cirrhosis), certain metabolic problems (e.g., hyperchloremic acidosis). Before using this medication, tell your doctor or pharmacist your medical history, especially of: breathing problems (e.g., emphysema, chronic bronchitis), high levels of calcium, dehydration, diabetes mellitus, gout, narrow-angle glaucoma, overactive thyroid (hyperthyroidism). While this medication can help you get used to high altitudes and help you tolerate quick climbs, it cannot completely prevent serious altitude sickness. Symptoms of serious altitude sickness may include: severe shortness of breath, mental/mood changes (e.g., confusion, difficulty concentrating), lack of coordination/staggering walk, extreme tiredness, severe headache. If you develop any of these symptoms, it is very important that you descend to a lower altitude as quickly as possible to prevent serious, possibly fatal problems. This drug may make you dizzy or drowsy or cause blurred vision. Do not drive, use machinery, or do any activity that requires alertness or clear vision until you are sure you can perform such activities safely. Limit alcoholic beverages. To minimize dizziness and lightheadedness, get up slowly when rising from a seated or lying position. This drug may infrequently make your blood sugar levels rise, causing or worsening diabetes. Tell your doctor immediately if you develop symptoms of high blood sugar such as increased thirst or tiredness. If you already have diabetes, be sure to check your blood sugar levels regularly. This medication may also cause your blood sugar levels to fall. Symptoms of low blood sugar include fast/pounding heartbeat, shakiness, hunger and sweating. It is a good habit to carry glucose tablets or gel to treat low blood sugar. If you are in a situation where you don't have these reliable forms of glucose, eat a quick source of sugar such as table sugar, honey, or candy, or drink a glass of orange juice or non-diet soda to quickly raise your blood sugar level. Tell your doctor immediately about the reaction. This medication may make you more sensitive to the sun. Avoid prolonged sun exposure, tanning booths and sunlamps. Use a sunscreen and wear protective clothing when outdoors. This medication should not be used in children less than 12 because it may affect normal growth. This medication should be used with caution in the elderly because they may be more sensitive to its side effects, especially low potassium or sodium levels. This medication should be used during pregnancy only if clearly needed. Discuss the risks and benefits with your doctor. This medication passes into breast milk but is unlikely to harm a nursing infant. Consult your doctor before breast-feeding.

Store at room temperature between 68-77 degrees F (20-25 degrees C) away from moisture and sunlight. Do not store in the bathroom. Keep all medications away from children and pets. Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company for more details about how to safely discard your product.

Dizziness, lightheadedness, and an increased amount of urine may occur, especially during the first few days as your body adjusts to the medication. Blurred vision, dry mouth, drowsiness, loss of appetite, stomach upset, headache and tiredness may also occur. If any of these symptoms persist or worsen, notify your doctor or pharmacist. Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects. Tell your doctor immediately if any of these very unlikely but serious side effects occur: increased body hair, hearing loss, ringing in the ears, unusual tiredness, persistent nausea/vomiting, severe stomach/abdominal pain. Seek immediate medical attention if any of these unlikely but very serious side effects occur: easy bleeding/bruising, fast/irregular heartbeat, signs of infection (e.g., fever, persistent sore throat), mental/mood changes (e.g., confusion, difficulty concentrating), severe muscle cramps/pain, tingling of the hands/feet, blood in the urine, dark urine, painful urination, yellowing of the eyes/skin. A very serious allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of a serious allergic reaction may include: blisters/sores in the mouth, rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing. This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist. In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088. In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

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. Acetazolamide may also be used to treat periodic paralysis.