Diamox (Acetazolamide): Characteristics and Uses

Diamox is a drug that promotes urination in the patient, and therefore, the elimination of excess fluids. It is very useful in treating open-angle glaucoma, for example.

Written and verified by el biólogo Samuel Antonio Sánchez Amador.

Last update: 03 July, 2023

Diamox is the brand name for a drug that has acetazolamide as its active ingredient. This is a carbonic anhydrase enzyme inhibitor that’s used to treat glaucoma, epilepsy, vertigo, periodic paralysis, and heart failure. Due to its peculiarities as a chemical compound, it also has a considerable diuretic action.

There are also other medications that have acetazolamide as the main compound. This drug group can also be found under the name Edemox, in addition to the fact that there are generic drugs that directly bear the name of the active compound.

This active principle was approved for medical use in 1952 and is on the WHO Model List of Essential Medicines. If you want to know more about its uses, side effects and contraindications, keep reading.

What is Diamox used for?

Diamox is a carbonic anhydrase enzyme inhibitor. This is a metalloenzyme that catalyzes the conversion of carbon dioxide and water to bicarbonate and protons. Depending on its location, it can promote the release of gastric acids, control bicarbonate ions in the kidneys, and modulate the amount of fluids present in the eyes, for example.

Carbonic anhydrase is found in red blood cells and renal tubules, where its function is to promote the reabsorption of sodium, bicarbonate, and chloride. If this enzyme is inhibited, the mentioned compounds are excreted instead of absorbed. With them, greater amounts of water are also released, which results in the reduction of pressure in certain areas of the body.

Inhibition of the enzyme carbonic anhydrase may be necessary in various clinical conditions, especially those related to the eyes. Let’s see what Diamox is used for, based on the assessments made by the Food and Drug Administration (FDA).

FDA approved indications

The FDA envisions the use of acetazolamide – and therefore Diamox – to treat the following clinical pictures:

• Glaucoma: Glaucoma is usually caused by an increase in intraocular pressure, derived from poor fluid drainage. Little by little, the optic nerve is damaged and the patient loses vision, slowly but irreversibly. Diamox helps to decrease pressure within the eye, as it allows the body to eliminate more fluids in the eyes.
• Idiopathic intracranial hypertension: In these cases, cranial pressure increases and the event can’t be explained by the presence of tumors or lesions. Releasing more water in the urine can help lower intracranial pressure.
• Congestive heart failure: The heart doesn’t pump blood properly, and fluids build up in the lungs, liver, and other organs. The excretion of excess fluids can help reduce the symptoms of this condition.
• Periodic paralysis: According to the Cochrane medical portal, acetazolamide may also help improve muscle tone in people with periodic paralysis.
• Epilepsy: This drug can be useful in some types of epilepsy, along with other specific medications.

Indications not approved by the FDA

Although the usefulness of acetazolamide hasn’t been fully verified in some cases, doctors prescribe it because of its potential beneficial effects. Diamox can be used in these cases to treat central sleep apnea, dural ectasia in Marfan syndrome, and methotrexate-induced kidney damage.

How is it administered?

We’re now going to explain the peculiarities of Diamox, using the leaflets of this specific drug and other similar ones with the same concentration of active principle (acetazolamide).

Presentations

Acetazolamide is consumed orally, as the Diamox and Edemox brands are only sold as tablets. It’s recommended to take the dose established by the doctor on an empty stomach, but if the patient has nausea, it can be accompanied by milk or food. The pill should be swallowed and shouldn’t be sucked or chewed.

Dose

The dose varies a lot depending on the type of pathology to be treated, and some conditions don’t have specific amounts. We present a list with its general dosage:

• Diuretic: The starting dose is 250 milligrams a day, that is, 1 tablet every 24 hours in the morning. If the patient responds adequately, the dose can be reduced to 1 tablet every 48 hours.
• Glaucoma: This drug isn’t usually used alone to treat glaucoma and must be accompanied by other medications. The dose in adults will be 1 to 4 tablets per day. When you exceed 1 gram a day, you don’t get better results. Children should never take more than 750 milligrams a day.
• Epilepsy: 250 milligrams (1 tablet) to 1000 milligrams (4 tablets) a day in several doses. Again, in children, the limit remains at 750 milligrams.

On the other hand, it’s recommended to take the medicine at breakfast time, in case you’re only consuming one tablet a day. If more pills are taken, the doses are usually spread throughout the day until 6-8 pm, unless otherwise directed by the doctor. This is done so that the diuretic effect doesn’t disturb the patient’s sleep.

Who shouldn’t take Diamox?

First of all, Diamox shouldn’t be taken by anyone who has a history of previous hypersensitivity reactions (allergies) to acetazolamide or sulfa drugs.

On the other hand, it should be used with great care – in lower doses – or directly avoid administration in patients with hepatic insufficiency (HI) or renal insufficiency (IR).

It’s especially necessary to review the possible effects of treatment in people with liver failure. Because Diamox decreases the secretion of ammonia in the urine, it could promote the accumulation of toxins in the blood. This results in brain effects caused by liver dysfunction, such as encephalopathy.

Acetazolamide can lead to electrolyte abnormalities. For this reason, people who already show hypokalemia (a lack of potassium) and hyponatremia (a lack of sodium) should avoid their consumption. Nor is its use recommended in hyperchloremic acidosis and adrenal insufficiency.

Diamox during pregnancy

According to the Australian Drug Categories, this drug is in category B3 as far as pregnancy is concerned. This means that the harmful effects of the drug have been demonstrated in rats and other laboratory animals, although there isn’t enough evidence to recommend it for humans.

Even so, treatment during the first trimester of pregnancy is completely contraindicated.

Diamox while breastfeeding

It has been observed that women in treatment produce less milk in the lactating phase, as indicated by sources already cited. Although this is unlikely to cause negative effects on the child, breastfeeding or drug administration should be stopped in these conditions.

What are the possible side effects?

There’s a wide spectrum of specific and general side effects that Diamox can cause in the patient. We explore them below based on the duration of treatment.

Effects in short-term therapies

In short-term therapies, it’s normal for patients to experience tingling, ringing in the ears, hearing loss, weight loss, taste disturbances, nausea, diarrhea, vomiting, flushing, fatigue, irritability, depression, and other general signs.

Transient photosensitivity and confusion have also been reported, although all symptoms disappear if treatment is discontinued.

On the other hand, the most common is that the patient notices that they urinate more often – due to the excretion of liquids. As you can expect, this will be accompanied by a natural increase in thirst. Discuss with your doctor how to manage these clinical signs on a day-to-day basis.

Long-term therapy effects

Long-term therapy reports many more associated clinical signs. Here is a list of some of the most important:

• Metabolic acidosis or excessive acidity in the bloodstream and changes in the internal electrolyte balance. This includes hypokalemia and hyponatremia.
• Bloody dark stools.
• The presence of sugar, blood, or crystals in the urine, which shows renal dysfunction.
• Yellowing of the skin and eyes.
• Low blood levels of red blood cells, white blood cells, and platelets.
• Fever.
• Acute inflammatory diseases.
• Kidney injuries

If you’re taking this drug and you notice any adverse effect that worries you, check with your doctor. You may need to readjust the dose or stop the treatment altogether. In any case, never stop taking the pills on your own or lower the consumption without consulting it beforehand.

What happens if I miss a dose?

If you’re taking Diamox and you miss a dose, it’s best to take the pill as soon as you remember. This is especially true for patients who only take one tablet a day, as they have time between doses to correct their mistake.

In any case, if you take 4 or 5 tablets a day and it’s easy for your doses to overlap, it’s best to skip the dose you have forgotten and continue with the treatment as normal. Never take 2 pills to counteract the error, as you run the risk of reaching dangerous concentrations of the drug in the body.

How should I act in case of a Diamox overdose?

As indicated by the Statpearls medical portal, potentially toxic effects of acetazolamide on the central nervous system (CNS) have been observed. This results in symptoms such as fatigue, lethargy and confusion that continue over time. In any case, the clinical signs disappear as soon as the treatment is definitively stopped.

Overdoses in the home environment are possible, especially if the patient is consuming an amount of the drug that’s close to the limit – 1.5 grams per day. If after taking more doses than prescribed you experience headache, nausea, vomiting, confusion, dizziness, seizures or fever, call the emergency room immediately and seek help from your surroundings while the professionals arrive.

How to store and dispose of this medicine?

This drug comes in the form of oral pills and doesn’t require any special preservation method. It’s enough to keep the box out of the reach of children at room temperature. Even so, it’s advisable to keep the medicine in an area that isn’t excessively humid or hot (such as the bathroom).

If you want to get rid of a Diamox box because it has expired or you don’t need it, don’t throw it away or put it down the drain. Find a medicine recycling point managed by the authorities in your country.

Final notes

Diamox is one of the drugs that have acetazolamide as the active ingredient, an inhibitor of the carbonic anhydrase enzyme that promotes urination and the elimination of excess fluids. It’s very useful in open-angle glaucoma and intracranial hypertension, although it’s also used as support therapy in epilepsy and other specific conditions.

If you’re going to start a treatment with this drug, inform your doctor well of possible liver failure, kidney dysfunction or systemic conditions that are already present. This medicine is very useful, but it can make the patient’s situation worse if they already have certain illnesses.