Acetazolamide (a SEET a ZOLE a mide)  has been FDA-approved for the treatment of, along with other drugs, centrencephalic epilepsies (absence, generalized seizures).

Your epilepsy treatment should always be discussed with your healthcare provider before use. Based on their judgment and knowledge, a drug may be prescribed for other epilepsy types not included in the indications. For more information, please see the prescribing information.

How can you take acetazolamide? (Available formulations)

Acetazolamide is available in a powder that can be reconstituted (dissolved in a solution) for intravenous use in patients with epilepsy. It is also available as a capsule or powder for oral suspension that is immediately taken during a meal, as well as an extended-release capsule to be taken with or without food.

Who should not take acetazolamide?

If you are allergic to acetazolamide or any of the inactive ingredients, then you should not take it. Since acetazolamide belongs to a group of drugs called sulfonamides (a group of man-made drugs that contain part of a molecule called a “sulfonamide”), tell your healthcare provider if you are allergic to any sulfonamides or diuretics (‘water pills’).

You should not take acetazolamide if you have severe liver disease or cirrhosis (liver scarring), severe kidney disease, an electrolyte imbalance (such as acidosis or low levels of potassium or sodium in your blood), or adrenal gland failure.

Other considerations may influence whether you should take acetazolamide. Tell your healthcare provider if you:

  • are allergic to any other drugs.
  • have severe breathing problems.
  • take aspirin in high doses.
  • have or have ever had heart, liver, or kidney disease.
  • have diabetes.
  • are pregnant or plan to become pregnant.
  • are breastfeeding or plan to breastfeed.

What is important to know about taking acetazolamide?

If you are having surgery, including dental surgery, tell the healthcare provider or dentist that you are taking acetazolamide.

Acetazolamide may make your skin sensitive to sunlight. Plan to avoid unnecessary or prolonged exposure to sunlight and to wear protective clothing, sunglasses, and sunscreen.

Do not stop taking acetazolamide suddenly unless directed to do so by your healthcare provider.

As with all antiseizure medications, acetazolamide should be withdrawn gradually to minimize the risk of causing or worsening seizures or status epilepticus. You should not stop using acetazolamide suddenly unless your healthcare provider tells you to stop the medicine because of a serious side effect.

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements.

Taking acetazolamide with certain other medicines may cause side effects or affect how well they work. Do not start or stop other medicines without talking to your healthcare provider. Especially tell your healthcare provider if you take: amphetamines, aspirin, cyclosporine, medications for depression or irregular heartbeat, diflunisal, digoxin, diuretics (‘water pills’), lithium, phenobarbital, primidone, and vitamins.

Do not drive or operate machinery until you have gained sufficient experience on acetazolamide to gauge whether it adversely affects your abilities.

You should know that acetazolamide may make you drowsy. Do not drive a car or operate machinery until you know how this drug affects you. Remember that alcohol can add to the drowsiness caused by this drug.

Women or those who are/plan to become pregnant
Use in pregnancy

At this time, there is not enough evidence regarding developmental risks associated with the use of acetazolamide in pregnant people. In animal studies, there were instances of developmental issues. However, having a seizure during pregnancy could harm both the pregnant individual and the baby. Tell your healthcare provider right away if you become pregnant. Do not start or stop taking seizure medication during pregnancy without your healthcare provider’s advice.

If you become pregnant while taking acetazolamide, talk to your healthcare provider about registering with the North American Antiepileptic Drug (NAAED) Pregnancy Registry. The purpose of this registry is to collect information about the safety of antiseizure medicine during pregnancy. You can enroll in this registry by calling 1-888-233-2334.

Use during breastfeeding

Acetazolamide can pass into breast milk and may harm a nursing baby. You should not breastfeed while using this medicine. Talk to your healthcare provider about the risks. Your healthcare provider will consider the developmental and health benefits of breastfeeding along with your need for acetazolamide and the potential effect on the infant from acetazolamide or from your epilepsy.

What are the side effects of acetazolamide?

Acetazolamide is approved by the FDA because it is safe and effective for the majority of people who take it. However, there are risks associated with all medicines. Some side effects caused by acetazolamide can be very serious, and even life-threatening. It is important to be informed about these serious reactions and to be aware of their symptoms.

Common side effects

The most common side effects that were reported in studies of acetazolamide are numbness or tingling, especially in your arms and legs; hearing problems or ringing in your ears; loss of appetite or taste alteration; gastrointestinal disturbances such as nausea, vomiting, and diarrhea; increased urination, and occasional instances of drowsiness and confusion.

Rare, but serious side effects
Sulfonamide hypersensitivity reactions

Acetazolamide belongs to a group of drugs called sulfonamides. Sulfonamides have resulted in severe reactions and have in rare cases caused death. If you have ever had a severe reaction to any drug, be sure to tell your healthcare provider as taking even a related drug again may cause an even stronger reaction. These reactions result in many different symptoms.

A reaction to sulfonamides may cause life-threatening rashes including Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). Call your healthcare provider at once if you have a severe skin reaction or symptoms such as fever, sore throat, swelling in your face or tongue, burning in your eyes, skin pain followed by a red or purple skin rash that spreads (especially in the face or upper body) and causes blistering and peeling.

These reactions may also take the form of liver failure, so call your healthcare provider right away if you have nausea, upper stomach pain or swelling, tired feeling, loss of appetite, dark urine, clay-colored stools, or jaundice (yellowing of the skin or eyes).

Hypersensitivity reactions may also result in problems with your blood cells. Therefore, call your healthcare provider right away if you experience sudden weakness or ill feeling, fever, chills, sore throat, mouth sores, pale skin, feeling tired or short of breath, rapid heart rate, nosebleeds, or bleeding gums.

Negative reactions with aspirin

Patients who take acetazolamide with high-dose aspirin may be at risk for severe side effects. Be sure to tell your healthcare provider if you take aspirin before starting acetazolamide, and if you develop symptoms such as confusion, vomiting, lack of energy, loss of appetite, irregular heartbeats, or shallow rapid breathing.