What is Diamox Used for in Glaucoma Care?

Diamox (acetazolamide) is an FDA-approved diuretic used to treat conditions that involve fluid buildup (edema). 

Common conditions treated include:¹

• Glaucoma
• Epilepsy
• High altitude sickness
• Periodic paralysis
• Idiopathic intracranial hypertension (IIH)

This drug has an average rating of 6.5 out of 10 from 70 reviews on Drugs.com.² Most users report a positive experience with the drug.

In this article, we’ll look at the following:

• Diamox and the condition it treats
• The working mechanism of Diamox
• The side effects of Diamox
• How to take Diamox (Dosage information)
• Diamox drug interactions 
• Common questions asked about Diamox

What is Diamox?

Diamox (acetazolamide) belongs to a group of drugs known as systemic carbonic anhydrase inhibitors.³ Other medications in this group include Neptazane® (methazolamide), Cardrase® (ethoxzolamide), and dichlorphenamide.

Diamox works by reducing the activity of a protein in your body called carbonic anhydrase. Blocking this protein reduces fluid buildup in certain body parts such as the eyes, heart, and brain.

The plasma half‐life of Diamox is 6 to 9 hours, and it’s eliminated in urine. It comes as a powder, tablet, or capsule.

What is Diamox Used to Treat?

Below are common conditions Diamox helps treat:

Glaucoma

Glaucoma is damage to the optic nerve caused by fluid buildup and pressure in the eye (ocular hypertension). If not treated, glaucoma can damage the optic nerve, the part behind the eye that transmits visual information to the brain. Optic nerve damage can lead to permanent blindness.

Although there are other treatments for glaucoma, such as surgery and eye drops, Diamox is useful in the short-term, such as after surgery.

High Altitude Sickness

High altitude sickness, or mountain sickness, occurs when you reach higher elevations than your body is used to (mostly higher than 8,000ft). 

Low oxygen in the body (hypoxia) causes one to experience the following:

• Headaches
• Nausea
• Fatigue
• Sleep apnea
• Shortness of breath, among other symptoms

Most cases of high altitude sickness are mild, but some, like pulmonary edema, can be life-threatening.⁴ Pulmonary edema is characterized by fluid buildup in the lungs and shortness of breath.

Doctors prescribe Diamox to reduce carbon dioxide (CO2) levels in the body. The medication stimulates ventilation and increases blood oxygen, a process known as ventilatory acclimatization.⁵ 

According to the Centers for Disease Control and Prevention (CDC), high-elevation ventilatory acclimatization typically takes 3 to 5 days. With Diamox, this process only takes a day.⁶

Periodic Paralysis

Periodic paralysis (PP) is a rare hereditary condition caused by defects in ion channels that control how charged minerals move in and out of muscle cells. People with periodic paralysis experience sudden attacks of short-lived muscle weakness or paralysis. 

There are two types of periodic paralysis:

• Hypokalemic periodic paralysis (low blood potassium levels)
• Hyperkalemic periodic paralysis (high blood potassium levels)

Acetazolamide has been a common treatment for periodic paralysis since 1968.⁷ It indirectly affects skeletal muscle cells as it regulates mineral movement across muscle cells. 

According to research, 375 to 500 mg daily can eliminate severe hypokalemia attacks more effectively than potassium or spironolactone treatment.⁸

Idiopathic Intracranial Hypertension (IIH)

Increased intracranial pressure (pressure inside the skull) is often caused by cerebrospinal fluid (CSF) accumulation.⁹ This may be due to the overproduction or poor reabsorption of CSF. 

Common symptoms include:

• Headaches
• Double vision
• Ear ringing
• Neck pain
• Shoulder pain

Diamox has proven effective in reducing the production of CSF in cases of raised intracranial pressure. This is why it’s considered the drug of choice for treating idiopathic intracranial pressure.

Seizures

Research shows Diamox is an anticonvulsant that can reduce major and minor seizures, including generalized tonic-clonic (GTC), absence, and myoclonic. 

A study conducted on children (aged between 6 months to 11 years old) showed that Diamox could treat most seizures, including absence seizures (petit mal).¹⁰ 

Despite its anti‐seizure effects, Diamox is rarely prescribed for seizures due to potential adverse effects and the risk of developing tolerance.⁸

Congestive Heart Failure (CHF)

Congestive heart failure is caused by the long-term accumulation of blood and fluid in the lungs due to inefficient blood pumping. Symptoms can include:

• Shortness of breath
• Swollen legs
• Rapid heartbeat
• Fatigue

According to studies, adding doses of Diamox (500 mg once daily) in intravenous loop-diuretic therapy can reduce proximal tubular sodium reabsorption. This results in decongestion in people with decompensated heart failure.¹¹

How Does Diamox Work in the Body?

Diamox works by reducing the activity of a protein known as carbonic anhydrase.¹² This protein is found in red blood cells, the brain, kidneys, and osteoclasts, among other tissues, and is needed to convert water and carbon dioxide into bicarbonate and hydrogen ions. 

Blocking this protein does the following to your body:

• Excretes more bicarbonate, sodium, potassium, and water, making the urine more alkaline.
• Reduces fluid buildup that can affect blood pressure and intracranial pressure.
• Reduces aqueous humor levels in the eyes. Aqueous humor is the clear liquid found between the lens and cornea of your eye. 
• Causes metabolic acidosis (acid buildup in the body) by increasing the urinary excretion of bicarbonate
• Affects neuron function in the central nervous system (CNS)

How Should Diamox Be Taken?

Take Diamox according to your doctor’s dosing instructions. Also, read the manufacturer’s printed instructions for a comprehensive list of potential side effects and user directions, including proper storage.

For tablets, your doctor might prescribe one to four tablets daily, taken in several doses throughout the day. For capsules, it may be one to two daily. The specific dosage, duration between doses, and length of taking Diamox will depend on your condition. 

Try to take your doses at the same time each day (before or after meals) to avoid forgetting. 

The following are recommended Diamox doses for adults (tablet form):

• Open-angle glaucoma. 250mg per day (no more than 1 gram (g) per day).
• Secondary and acute closed-angle glaucoma. Take 250mg 2 times a day or every 4 hours. 
• Congestive heart failure (CHF). Take 250 to 375 milligrams (mg) once daily. Your doctor may adjust your dose as needed.
• Periodic paralysis. Take 250mg 1 to 3 times daily.
• Edema. Take 250 to 375 mg once daily for one or two days, with a rest day in between.
• Acute mountain sickness. Take 500 to 1000 mg in portions. Take your dose 24 to 48 hours before climbing, then continue as needed.
• Seizures (Diamox alone). The dosage depends on body weight—usually, 8 to 30mg per kilogram (kg) of body weight, taken in divided doses, is recommended. 
• Seizures (Diamox plus other drugs). Take 250 mg once a day.

If you are taking acetazolamide capsules, they are specially formulated to release the medicine slowly throughout the day. Do not chew or open the capsules, as this will affect their efficacy.

Note: Your doctor may adjust your dose depending on your specific situation. For children, the use and dosage of Diamox must be determined by a medical professional.

What if You Miss a Dose of Diamox?

If you miss a dose, don’t panic. Take it as soon as you remember. Never take a double dose to compensate for a missed dose. Doing so may cause an overdose. If it’s already time for your next dose, skip the missed dose.  

What are the Common Side Effects of Diamox?

Common side effects of Diamox include:

• Nausea and vomiting
• Diarrhea
• Loss of appetite or altered sense of taste
• Headache
• Numbness, itchiness, or tingling feeling, especially in your arms and legs
• Drowsiness or confusion
• Hearing issues such as ringing in your ears
• Increased urination
• Unusual tiredness
• Joint or muscle pain
• Muscle tremors
• Heavier menstrual periods

This is not a complete list of common side effects, and they may vary from one person to another. 

Consult your doctor for medical advice about the drug’s side effects. You can also report unusual side effects to the FDA at 1-800-FDA-1088.

What are the Serious Side Effects of Diamox?

Some people experience severe side effects after taking acetazolamide. These can include:

• Bloody urine or stools
• Seizures (convulsions)
• Sudden weakness or feeling sick (fever, chills, sore throat, pale skin)
• Severe skin reaction (such as swollen face or tongue, burning eyes, a skin rash that spreads, blistering, etc.) 
• Loss of movement abilities in some body parts
• Feeling tired or shortness of breath
• Rapid heart rate or irregular heartbeats
• Nosebleeds or bleeding gums 
• Jaundice (yellowing of the skin or eyes), which can indicate liver problems
• Upper stomach pain or swelling
• Kidney stones (lower back pain, bloody urine, painful or difficult urination)

Seek emergency medical attention if you or your loved one experiences allergic reactions, such as swelling, hives, or difficulty breathing.

What Precautions Should You Take When Using Diamox?

While using Diamox, you must take several precautions to ensure success and prevent adverse effects. Observe the following:

1. Inform your healthcare provider or dentist of your Diamox prescription if you are undergoing surgery.
2. Diamox may cause skin sensitivity to sunlight. Wear protective clothing and eyewear when outside.
3. Only stop taking Diamox suddenly if directed by your doctor.
4. To withdraw from Diamox, do it gradually to avoid the risk of seizures, nausea, headaches, and other severe withdrawal symptoms. Only stop suddenly if your doctor advises.
5. Inform your doctor about all your medicines, including over-the-counter drugs, antidepressants, supplements, etc., to prevent adverse drug interactions or reduced efficacy.
6. Do not drive or operate machinery unless you’re used to the side effects, and they do not affect your mental or physical abilities.

Potential Drug Interactions

Other drugs may interact with Diamox (acetazolamide), causing severe to moderate consequences. These may include prescription and over-the-counter medicines, vitamins, and herbal products. 

Common drugs that interact with Diamox include:

• Aspirin
• Sodium bicarbonate
• Metformin
• Topamax (topiramate)
• Xanax (alprazolam)
• Prednisone
• Lexapro (escitalopram)
• Cymbalta (duloxetine)
• Stimulants like dextroamphetamine
• Other diuretics

This is not a complete list of drugs that can interact with Diamox. Tell your doctor about your active medications. They will advise you on whether Diamox is safe for you.

Who Shouldn’t Take Diamox?

Despite the significant benefits of Diamox, it’s not suitable for everyone. 

Avoid Diamox or talk to your doctor if:

• You’re allergic to acetazolamide or any of the inactive ingredients
• You’re allergic to sulfonamides or diuretics (“water pills”)
• You have an underlying health condition such as diabetes, severe liver disease (cirrhosis), severe kidney disease, electrolyte imbalance, or adrenal gland failure
• You are pregnant or plan to become pregnant
• You are breastfeeding or plan to breastfeed
• You are allergic to any other drugs
• You have severe breathing problems
• You take aspirin in high doses
• You have a history of liver, heart, or kidney disease

Can You Overdose on Diamox?

Taking too much Diamox than prescribed may cause an overdose characterized by changes in blood electrolyte concentrations and acidity levels. This can potentially cause damage to the kidneys, liver, and other organs. 

Common symptoms of Diamox overdose include:

• Dizziness
• Confusion
• Loss of consciousness
• Convulsions
• Decreased urination

Call the poison control center at 1-800-222-1222 if you suspect a Diamox overdose. If your loved one has collapsed, had a seizure, has trouble breathing, or can’t be awakened after taking Diamox, call 911 for emergency assistance.

Does Diamox Have an Effect on Blood Pressure and Kidneys?

Diamox affects blood pressure, especially at high altitudes. It reduces blood pressure and sleep-disordered breathing in people with hypertensive obstructive sleep apnea.

Diamox also affects the kidneys. When Diamox is used for increased pressure and edema, it can cause dehydration, resulting in swelling and inflammation of the kidneys. 

Symptoms of kidney toxicity can vary from person, but common ones include:

• Decreased amount of urine
• Swollen feet or ankles
• Fatigue, nausea, and confusion
• Shortness of breath
• Pressure or pain in the chest

These symptoms may vary from person to person.

Can Diamox Cause Kidney Stones?

Acetazolamide can induce metabolic acidosis (buildup of acid in the body). Metabolic acidosis can cause kidney stones in vulnerable people. 

If you’ve had a history of kidney stones or are taking any medications, consult your doctor for alternatives.

Are There Alternatives to Diamox?

Other carbonic anhydrase inhibitors can be used in place of Diamox. 

• Methazolamide. For treating glaucoma.
• Dorzolamide. For reducing intraocular pressure.
• Diclofenamide. Used to treat open-angle glaucoma, secondary glaucoma, and acute angle-closure glaucoma in pre-operative settings.
• Ethoxzolamide. Used in the treatment of glaucoma and epileptic seizures.
• Topamax (topiramate) and Zonegran (zonisamide). A selective carbonic anhydrase inhibitor prescribed for seizures in epilepsy.
• Ibuprofen. A weak carbonic anhydrase II inhibitor. It’s effective for inflammation, headaches, and muscle pain associated with high altitude sickness.
• Dexamethasone. More effective than Diamox for inflammation associated with acute mountain sickness.
• Hydrochlorothiazide.¹³ Prescribed for edema.

Summary

• Diamox (acetazolamide) is an FDA-approved diuretic medication commonly used to treat glaucoma, epilepsy, high altitude sickness, periodic paralysis, CHF, and idiopathic intracranial hypertension (IIH).
• Diamox works by reducing the activity of carbonic anhydrase. Blocking this protein reduces the buildup of fluid in certain body parts.
• Common side effects of Diamox include a tingling sensation, headaches, loss of appetite, ringing of the ears, nausea, etc.
• Serious side effects may include bloody urine or stools, seizures, sudden weakness or feeling sick (fever, chills, mouth sores, pale skin), severe skin reaction, shortness of breath, etc.
• The specific dosage, duration between doses, and length of taking Diamox will depend on your condition. Strictly follow your doctor’s instructions.
• Avoid Diamox if you have a history of heart, liver, or kidney disease, are pregnant, breastfeeding, or are taking other drugs such as aspirin.