Acetazolamide

Acetazolamide is a prescription medication used to treat glaucoma and symptoms of acute mountain sickness. Acetazolamide is used with other medicines to reduce edema (excess fluid retention) and to help control seizures in certain types of epilepsy. Acetazolamide belongs to a group of drugs called carbonic anhydrase inhibitors, which help to reduce amount of fluid in the eye and to reduce adverse symptoms when at high altitudes.

This medication comes in tablet and an extended release capsule form, and is taken with or without food.

Acetazolamide also available in an injectable form to be given directly into a vein (IV) by a healthcare professional.

Common side effects of acetazolamide include rash, fever, and reduced field of vision. Acetazolamide may cause dizziness, drowsiness, or blurred vision. Do not drive or operate heavy machinery until you know how acetazolamide affect you.

Acetazolamide is a prescription medication used to treat glaucoma. Acetazolamide is used to reduce the severity and duration of symptoms (upset stomach, headache, shortness of breath, dizziness, drowsiness, and fatigue) of altitude (mountain) sickness. Acetazolamide is used with other medicines to reduce edema (excess fluid retention) and to help control seizures in certain types of epilepsy.

This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.

Acetazolamide may be found in some form under the following brand names:

• Diamox

Serious side effects have been reported with acetazolamide. See the “Drug Precautions” section.

Common side effects of acetazolamide are:

• rash
• fever
• reduced field of vision
• upset stomach
• vomiting
• loss of appetite
• change in taste

This is not a complete list of acetazolamide side effects. Ask your doctor or pharmacist for more information.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Tell your doctor about all the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements. Especially tell your doctor if you take:

• aspirin (Ecotrin)
• phenytoin (Dilantin)
• primidone (Mysoline, Desoxyphenobarbital, Primaclone)
• other carbonic anhydrase inhibitors such as methazolamide (Neptazene), dorzolamide (Trusopt), and topiramate (Topamax)
• folic acid antagonists such as methotrexate (Trexall, Rheumatrex), trimethoprim (Bactrim, Septra, Primsol, Proloprim, Trimpex), pyrimethamine (Daraprim), pemetrexed (Alimtra), and raltitrexed (Tomudex)
• dexamphetamine/amphetamine salts (Adderall)
• quinidine (Duraquin, Quinalan, Quinact)
• methenamine (Hiprex, Urex, Mandelamine)
• lithium (Eskalith, Lithobid)
• cyclosporine (Gengraf, Neoral, Sandimmune)
• sodium bicarbonate

This is not a complete list of acetazolamide drug interactions. Ask your doctor or pharmacist for more information.

Serious side effects have been reported with acetazolamide including:

• paresthesias, particularly a “tingling” feeling in the extremities. Occurs most often early in therapy.
• tinnitus (noise or ringing in the ears)
• hypersensitivity (severe allergic reaction). Signs of a hypersensitivity reaction, which include the following:
  • chest pain
  • swelling of the face, eyes, lips, tongue, arms, or legs
  • difficulty breathing or swallowing
  • fainting
  • rash
• loss of blood sugar control. Caution is advised in those with impaired glucose (blood sugar) tolerance or in those with diabetes.
• electrolyte imbalances. Electrolytes are minerals in your body that help your body function normally. An imbalance could lead to abnormalities such as arrhythmias (with low or high levels of potassium), a change in body fluid (due to low or high levels of sodium), and altered acidity levels of your blood.
• anaphylaxis, fever, rash (including erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis)
• decrease in blood counts

Acetazolamide may cause dizziness, drowsiness, or blurred vision. Do not drive or operate heavy machinery until you know how acetazolamide affect you.

Do not take acetazolamide if you:

• have an allergic reaction to acetazolamide or any of its ingredients
• have a history of an allergic reaction to sulfonamides
• have lowered levels of sodium and/or potassium blood levels in cases of kidney and liver disease or dysfunction, in suprarenal gland failure, and in hyperchloremic acidosis
• have a history of cirrhosis because of the risk of development of hepatic encephalopathy
• are using acetazolamide for a prolonged duration and also have chronic non-congestive angle-closure glaucoma

Medications can interact with certain foods. In some cases, this may be harmful and your doctor may advise you to avoid certain foods. In the case of acetazolamide, there are no specific foods that you must exclude from your diet when receiving this medication.

Before taking acetazolamide, tell your doctor about all of your medical conditions. Especially tell your doctor if you:

• are allergic to acetazolamide or to any ingredient in acetazolamide
• have a sulfonamide allergy
• have liver problems
• have kidney problems
• have lung problems
• have adrenal gland problems
• have chronic non-congestive angle-closure glaucoma
• are pregnant or breastfeeding

Tell your doctor about all the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements.

Tell your doctor if you are pregnant or plan to become pregnant.

The FDA categorizes medications based on safety for use during pregnancy. Five categories - A, B, C, D, and X, are used to classify the possible risks to an unborn baby when a medication is taken during pregnancy.

Acetazolamide fall into category C. There are no well-controlled studies that have been done in pregnant women. Acetazolamide  should be used during pregnancy only if the possible benefit outweighs the possible risk to the unborn baby.

Tell your doctor if you are breastfeeding or plan to breastfeed.

Because of the possibility for serious negative reactions in nursing infants from acetazolamide, a decision should be made whether to stop nursing or to stop the drug. Acetazolamide should only be used by nursing women if the benefit outweighs the risk to the child.

Take acetazolamide exactly as prescribed.

This medication comes in a tablet form and can be given up to four times a day.

This medication comes in an extended release capsule form and is taken up to two times a day, with or without food.

• Do not chew, divide, or break acetazolamide capsules. Swallow capsules whole.

Acetazolamide also available in an injectable form to be given directly into a vein (IV) by a healthcare professional.

If you miss a dose, take the missed dose as soon as you remember. If it is almost time for the next dose, skip the missed dose and take your next dose at the regular time. Do not take two doses of acetazolamide at the same time.

Take acetazolamide exactly as prescribed by your doctor. Follow the directions on your prescription label carefully.

The acetazolamide dose your doctor recommends will be based on the following:

• the condition being treated
• other medical conditions you have
• other medications you are taking
• how you respond to this medication
• weight

Glaucoma

The recommended dose range for acetazolamide is 250 mg-1000mg/day. The number of times acetazolamide will be given will depend on the formulation being given.

Acute Mountain Sickness

The recommended dose range for acetazolamide is 500 mg-1000mg/day. The number of times acetazolamide will be given will depend on the formulation being given.

Edema

Recommended dosage is 250 to 375 mg of acetazolamide once a day for one or two days, alternating with a day of rest.

Diuresis in Congestive Heart Failure

The starting dose is usually 250 to 375 mg once daily in the morning.

Epilepsy

The recommended dose range for acetazolamide is 375 to 1000 mg daily.

If you take too much of this medication, call your healthcare provider or local Poison Control Center, or seek emergency medical attention right away.

If acetazolamide is administered by a healthcare provider in a medical setting, it is unlikely that an overdose will occur. However, if overdose is suspected, seek emergency medical attention.

• Store acetazolamide capsules and tablets at room temperature between 20° to 25°C (68° to 77°F).
• Keep this and all medicines out of the reach of children.

Warning:

Fatalities have occurred, although rarely, due to severe reactions to sulfonamides including Stevens-Johnson syndrome, toxic epidermal necrolysis, fulminant hepatic necrosis, agranulocytosis, aplastic anemia, and other blood dyscrasias. Sensitizations may recur when a sulfonamide is readministered irrespective of the route of administration. If signs of hypersensitivity or other serious reactions occur, discontinue use of this drug.

Caution is advised for patients receiving concomitant high-dose aspirin and acetazolamide, as anorexia, tachypnea, lethargy, coma and death have been reported.