Diamox (Acetazolamide) - Oral

What Is Diamox?

Diamox (acetazolamide) is a fast-acting prescription diuretic (water pill) indicated for treating glaucoma and acute mountain sickness (AMS). It is also used off-label for treating other medical conditions. The capsule form of this medication has been approved for adults over the age of 18, and it is taken orally (by mouth). The branded form of Diamox is not available in the United States. The generic version, acetazolamide, is available as a tablet and for intravenous (IV) use. 

Diamox is a carbonic anhydrase inhibitor. It works in several ways, including by altering the kidneys' hydrogen, fluid, and bicarbonate concentration to promote urination. It also reduces the production of cerebrospinal fluid (CSF), which relieves excess fluid pressure around the brain and spinal cord.

Drug Facts

Generic Name: Acetazolamide

Brand Name(s): Diamox

Drug Availability: Prescription

Therapeutic Classification: Diuretic, carbonic anhydrase inhibitor

Available Generically: Yes

Controlled Substance: No

Administration Route: Oral, intravenous (IV)

Active Ingredient: Acetazolamide

Dosage Form(s): Tablets, intravenous (IV) solution

What Is Diamox Used For?

Diamox reduces fluid in certain areas of the body. It can be used to treat some medical conditions caused by fluid accumulation or overproduction. Diamox has been approved for treating glaucoma and for treatment of acute mountain sickness (AMS).

Glaucoma is the second leading cause of blindness worldwide. According to the Centers for Disease Control and Prevention (CDC), around 3 million Americans have glaucoma. Many people do not know they have it because they may not have symptoms early in the disease. Certain groups are at higher risk of developing glaucoma, including Black people over the age of 40, people over age 60, people with a family history of glaucoma, and people with diabetes.

According to the CDC, AMS is the most common form of altitude illness. In Colorado, it affects around 25% of all visitors who are sleeping above 8,000 feet (2,500 meters). It can also happen around high-altitude activity (e.g., hiking, skiing). The symptoms of AMS include headache, fatigue, appetite loss, nausea, and sometimes vomiting. Young children who cannot talk yet may have appetite loss, irritability, and pale skin. While AMS typically gets better within 12 to 48 hours of acclimatization, medication might be needed.


Glaucoma is an eye condition that usually does not cause symptoms in the early stages but can cause vision loss if it progresses without treatment. In glaucoma, excess fluid around the optic nerve in the eye puts pressure on the nerve (intraocular pressure).

Diamox reduces intraocular pressure by decreasing the amount of fluid around the optic nerve. It is used with other treatments for glaucoma (adjunctive treatment).

Diamox can be helpful in treating:

  • Chronic open-angle glaucoma
  • Secondary glaucoma

Diamox can also be used before an operation in situations when reducing pressure in the eye would be beneficial prior to glaucoma surgery.

Acute Mountain Sickness 

AMS occurs when the body’s fluid concentration changes because a person is in a location that's at a higher elevation—especially when the altitude transition happens quickly. A person with AMS may experience headaches, dizziness, nausea, vomiting, irritability, and shortness of breath. 

Diamox can be effective in preventing and treating symptoms of AMS.

How to Take Diamox

Diamox can be taken with or without food. If you are taking Diamox, it is recommended that you drink plenty of fluid throughout the day to avoid dehydration.


Keep your medications tightly closed in their container and out of the reach of children and pets. Ideally, they should be locked in a cabinet or closet.

Store the medication at room temperature (68 to 77 degrees Fahrenheit or 20 to 25 degrees Celsius). Do not store your medication in the bathroom.

If you have medication that you no longer need, do not pour the unused or expired drugs down the drain or the toilet. Ask your pharmacist or healthcare provider about the best way to dispose of your medicine. You can check the FDA's website to find out where and how to discard all your unused and expired drugs. You can also look for disposal boxes in your area. Ask your pharmacist or provider if you have any questions about the right way to dispose of your medications.

If you plan to travel with Diamox, get familiar with your final destination's regulations. Make a copy of your Diamox prescription. If possible, keep your medication in its original container from your pharmacy with your name on the label. If you have any questions about traveling with your medicine, ask your pharmacist or healthcare provider.

Off-Label Uses

Diamox has been prescribed for many conditions off-label (for a reason other than what it was approved for). Several are approved uses of acetazolamide.

Standard off-label uses for Diamox include:

How Long Does Diamox Take to Work?

Diamox begins to work within hours. The effects start to wear off after four to eight hours.

What Are the Side Effects of Diamox?

This is not a complete list of side effects and others may occur. A healthcare provider can advise you on side effects. If you experience other effects, contact your pharmacist or a healthcare provider. You may report side effects to the Food and Drug Administration (FDA) at fda.gov/medwatch or 1-800-FDA-1088.

Common Side Effects

Diamox can cause side effects, even when used at recommended doses. Side effects are more likely at higher doses.

The most common side effects of Diamox include but are not limited to:

  • Headaches 
  • Fatigue
  • Fever
  • Nausea 
  • Vomiting 
  • Diarrhea
  • Decreased appetite 
  • Change in taste 
  • Tiredness 
  • Flushing 
  • Tingling sensations
  • Mood changes
  • Sun sensitivity 
  • Rash or itching 
  • Ringing in the ears

The side effects of Diamox are usually mild but some people have more severe side effects. In some cases, these side effects could be early signs of more severe reactions. Tell your healthcare provider even if you only have mild side effects when taking Diamox so you can be properly diagnosed and treated.

Severe Side Effects

Serious side effects of Diamox are not common. However, they require urgent medical attention if they do occur.

Contact your healthcare provider immediately if you develop signs of a severe reaction while taking Diamox. Call 911 if your symptoms feel life-threatening.

Serious side effects of Diamox and their symptoms include:

These side effects can be harmful in the long term. Get medical attention right away if you experience symptoms of these severe Diamox side effects.

Long-Term Side Effects

Diamox can cause long-term problems, especially if the side effects are not managed. 

Long-term side effects of Diamox can include:

  • Liver damage 
  • Kidney damage 
  • Delayed growth or inadequate growth in children 
  • Organ failure 
  • Death

Report Side Effects

Diamox may cause other side effects. Call your healthcare provider if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your provider may send a report to the FDA's MedWatch Adverse Event Reporting Program or by phone (1-800-332-1088).

Dosage: How Much Diamox Should I Take?

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The dose of this medicine will be different for different people. Follow your healthcare provider's orders or the directions on the medication's label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your healthcare provider tells you to.

The amount of medicine you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take medicine will depend on the health condition you're taking the medication for.

The following information is for the oral dosage form (tablets):

For congestive heart failure:

  • Adults—At first, 250 to 375 milligrams (mg) once daily in the morning. Your healthcare provider may adjust your dose as needed.
  • Children—Your healthcare provider must determine the use and dose.

For edema caused by other medicines:

  • Adults—250 to 375 milligrams (mg) once daily for one or two days, with a rest day.
  • Children—Your healthcare provider must determine the use and dose.

For mountain sickness:

  • Adults—500 to 1000 milligrams (mg) in divided doses, taken 24 to 48 hours before climbing, then continue for 48 hours at high altitude or as needed.
  • Children—Your healthcare provider must determine the use and dose.

For open-angle glaucoma:

  • Adults—At first, 250 milligrams (mg) per day. Your healthcare provider may adjust your dose as needed. However, the dose is usually not more than 1 gram (g) per day.
  • Children—Your healthcare provider must determine the use and dose.

For secondary and acute closed-angle glaucoma:

  • Adults—250 milligrams (mg) every 4 hours or twice daily. Your healthcare provider may adjust your dose as needed.
  • Children—Your healthcare provider must determine the use and dose.

For seizures (acetazolamide alone):

  • Adults—The dose is based on body weight and must be determined by your healthcare provider. The usual dose is 8 to 30 milligrams (mg) per kilogram (kg) of body weight, taken in divided doses. Your healthcare provider may adjust your dose as needed. However, the dose is usually not more than 1 gram (g) per day.
  • Children—Your healthcare provider must determine the use and dose.

For seizures (in combination with other anticonvulsants):

  • Adults—250 milligrams (mg) once a day. Your healthcare provider may adjust your dose as needed.
  • Children—Your healthcare provider must determine the use and dose.


The following modifications (changes) should be kept in mind when using Diamox:

Severe allergic reaction: Avoid using Diamox if you have a known allergy to it or any of its ingredients. Ask your pharmacist or healthcare provider for a complete list of the ingredients if you're unsure.

Missed Dose

If you accidentally forgot to take your Diamox dose, take it as soon as you remember. If it's already close to your next scheduled dose, skip the missed dose and take the following dose at your next scheduled dosing time. Do not "double up" to make up for the missed dose.

Try to find ways to help yourself remember to take your medication routinely. If you miss too many doses, Diamox might be less effective at treating your condition.

Overdose: What Happens If I Take Too Much Diamox?

Taking too much Diamox can be harmful to your health and increase the risk of severe side effects.

Too much Diamox can cause changes in blood electrolyte concentrations and blood pH, which can potentially lead to kidney and other organ damage. This can cause dizziness, confusion, loss of consciousness, convulsions, and decreased urination. 

The treatment of Diamox overdose involves closely monitoring fluid and electrolyte levels and administering IV fluids to correct imbalances. Symptoms are treated as they develop.

In some situations, dialysis might be needed to remove Diamox from the bloodstream.

What Happens If I Overdose on Diamox?

If you think you or someone else may have overdosed on Diamox, call a healthcare provider or the Poison Control Center (1-800-222-1222).

If someone collapses or is not breathing after taking Diamox, call 911 immediately.


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You and your healthcare provider must check your progress at regular visits. This will allow your provider to see if your medicine is working correctly and decide if you should continue using it.

If your symptoms do not improve within a few days or if they become worse, check with your provider.

Do not take other medicines unless you have talked to your provider about them. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal (e.g., St. John's wort) or vitamin supplements. Tell your provider if you drink grapefruit juice.

This medicine may cause severe skin reactions (e.g., Stevens-Johnson syndrome and toxic epidermal necrolysis). Check with your provider if you have blistering, peeling, or loosening of the skin, chills, cough, diarrhea, itching, joint or muscle pain, red, irritated eyes, red skin lesions, often with a purple center, sore throat, sores, ulcers, or white spots in the mouth or on the lips, or unusual tiredness or weakness.

Check with your provider immediately if you have pain or tenderness in the upper stomach, pale stools, dark urine, loss of appetite, nausea, vomiting, or yellow eyes or skin. These could be symptoms of a severe liver problem.

This medicine may cause severe allergic reactions, including anaphylaxis, which can be life-threatening and requires immediate medical attention. Tell your provider right away if you have chest tightness, cough, difficulty swallowing, dizziness, fast heartbeat, hives, itching, skin rash, puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue, trouble breathing, or unusual tiredness or weakness.

Tell your provider immediately if you have blood in your urine, nausea and vomiting, pain in your groin or genitals, or sharp back pain just below your ribs. These can be symptoms of kidney stones.

Tell your provider right away if you have chest pain or tightness, chills, cough or hoarseness, fever with or without chills, general feeling of tiredness or weakness, headache, lower back or side pain, painful or difficult urination, sore throat, sores, ulcers, or white spots in the mouth, swollen or painful glands, trouble breathing, unusual bleeding or bruising, or unusual tiredness or weakness. These can be symptoms of severe blood problems (e.g., agranulocytosis, aplastic anemia).

Taking this medicine with aspirin may cause change or loss of consciousness, loss of appetite, rapid shallow breathing, trouble breathing, or weight loss. Talk with your provider if you have any concerns.

Do not suddenly stop using this medicine without checking with your provider first. Stopping the medication suddenly may cause your seizures to return or to occur more often. Your provider may want you to gradually reduce the amount you take before stopping it completely.

What Are Reasons I Shouldn’t Take Diamox?

Do not use Diamox if you're allergic to it or any of its ingredients. Ask your pharmacist or healthcare provider for a full list of the ingredients if you're unsure.

What Other Medications Interact With Diamox?

In general, Diamox should not be used with other carbonic anhydrase inhibitors. Taking Diamox with sulfa drugs, such as aspirin, can increase the risk of severe reactions, including skin and blood reactions. 

Other medications that can interact with Diamox include:

  • Phenytoin: Taking these medications together increases the level of phenytoin in the blood, and long-term use of both medicines together increases the risk of osteomalacia
  • Primidone: Taking these medications together reduces primidone levels and can decrease the anticonvulsant effect of primidone. 

Diamox can increase the effects of:

  • Folic acid antagonists 
  • Amphetamines 
  • Quinidine
  • Cyclosporine 

Depending on your situation, your provider may make medication adjustments and/or closely monitor you if you are prescribed a combination of Diamox with one or more of these medicines.

Talk with your pharmacist or provider to get more detailed information about medication interactions with Diamox.

Tell your provider about any other medicines you take or plan to take, including over-the-counter (OTC), nonprescription products, vitamins, herbs, or plant-based medicines or supplements.

What Medications Are Similar?

Several carbonic anhydrase inhibitors are used to treat the same conditions as Diamox. 

Acetazolamide is the generic version. It has the same therapeutic effects and side effects as Diamox.

Methazolamide is a carbonic anhydrase inhibitor that is prescribed to treat glaucoma.

Topamax (topiramate) and Zonegran (zonisamide) are carbonic anhydrase inhibitors that are prescribed to prevent seizures in epilepsy.

Frequently Asked Questions

  • What is Diamox used for?

    Diamox is prescribed to treat conditions associated with excess fluid, including glaucoma, acute mountain sickness, cerebral edema (fluid around the brain), certain types of epilepsy, and pulmonary edema.

  • How does Diamox work?

    Diamox promotes the release of excess fluid in certain parts of the body by adjusting the concentration of hydrogen and other electrolytes. It is considered a carbonic anhydrase inhibitor.

  • What drugs should not be taken with Diamox?

    Taking other carbonic anhydrase inhibitors should be avoided if you're taking Diamox. Taking aspirin and Diamox together can cause severe adverse reactions. Several other medications interact with Diamox, and doses may need to be adjusted.

  • How long does it take for Diamox to work?

    Diamox begins to work within hours. The effects start to wear off after four to eight hours.

  • What are the side effects of Diamox?

    The most common side effect of Diamox is fluid and electrolyte imbalances, which can cause headaches, dizziness, confusion, loss of consciousness, or convulsions if not treated promptly. Generally, your electrolyte levels will be monitored if you are taking Diamox, especially if you are prescribed a high dose. The monitoring can help your provider identify irregularities early so that treatment can be started to prevent complications.

How Can I Stay Healthy While Taking Diamox?

Diamox is a diuretic that can cause dehydration and electrolyte imbalances. You need to drink enough fluids and maintain proper nutrition so your body can adjust your fluid and electrolytes while you are taking this medication. 

Be sure to familiarize yourself with Diamox's common and severe side effects so you can contact your healthcare provider if you develop symptoms. 

Additionally, you must follow instructions to manage your medical condition while taking Diamox. For example, if you are prescribed Diamox for managing acute mountain sickness (AMS), be sure to eat enough, wear appropriate sunscreen, and dress for the weather to avoid symptoms and side effects.

Medical Disclaimer

Verywell Health's drug information is meant for educational purposes only and is not intended as a replacement for medical advice, diagnosis, or treatment from a healthcare provider. Consult your healthcare provider before taking any new medication(s). IBM Watson Micromedex provides some of the drug content, as indicated on the page.

8 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. Centers for Disease Control and Prevention. Don't Let Glaucoma Steal Your Sight!.

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  4. Supuran CT. Emerging role of carbonic anhydrase inhibitors. Clin Sci (Lond). 2021 May 28;135(10):1233-1249. doi:10.1042/CS20210040

  5. Adamson R, Swenson ER. Acetazolamide use in severe chronic obstructive pulmonary disease. pros and cons. Ann Am Thorac Soc. 2017 Jul;14(7):1086-1093. doi:10.1513/AnnalsATS.201701-016FR

  6. Van Berkel MA, Elefritz JL. Evaluating off-label uses of acetazolamide. Am J Health Syst Pharm. 2018 Apr 15;75(8):524-531. doi:10.2146/ajhp170279

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By Heidi Moawad, MD
Heidi Moawad is a neurologist and expert in the field of brain health and neurological disorders. Dr. Moawad regularly writes and edits health and career content for medical books and publications.