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Acetazolamide

Acetazolamide is a prescription diuretic and carbonic anhydrase inhibitor used to treat glaucoma, altitude sickness, and fluid retention.Packaging and branding may differ from image shown.

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Acetazolamide is a versatile prescription medicine used to treat a variety of conditions involving fluid balance and pressure regulation. Most commonly, it is used to reduce intraocular pressure in glaucoma, relieve symptoms of fluid retention due to congestive heart failure, and help prevent altitude sickness in travellers ascending rapidly to high altitudes. It is also sometimes prescribed as an adjunctive treatment for specific types of seizures.

How It Works
Acetazolamide belongs to a class of medicines called carbonic anhydrase inhibitors. It works by inhibiting the enzyme carbonic anhydrase, which is involved in the regulation of fluid levels in the body. In the eyes, it reduces the production of aqueous humour, thereby lowering intraocular pressure—beneficial for glaucoma patients. In the kidneys, it promotes the excretion of sodium, bicarbonate, and water, resulting in diuresis. In the brain, it may alter cerebrospinal fluid dynamics, which is helpful in managing certain neurological conditions such as idiopathic intracranial hypertension.

Why Choose Acetazolamide
Acetazolamide offers rapid onset of action, making it particularly effective in managing acute symptoms of altitude sickness and fluid overload. Its use in multiple therapeutic areas, from ophthalmology to neurology, makes it a flexible tool in clinical practice. For travellers heading to high-altitude regions, a short course can significantly reduce the risk of acute mountain sickness, making it a go-to preventive strategy. The tablet form is easy to administer and widely available by prescription.

Important Note
Acetazolamide should only be used under medical supervision. It may cause changes in blood electrolytes and acid–base balance, and regular monitoring is often required during extended treatment. It is not suitable for individuals with severe liver or kidney dysfunction, certain types of glaucoma, or those allergic to sulphonamides. Patients may experience tingling in the extremities, changes in taste, or increased urination. It is not a substitute for proper acclimatisation at high altitude and should be used in combination with gradual ascent.

Directions

Always follow the patient information leaflet before use.

  • Dosage:

    • Glaucoma: 250 mg to 1 g daily in divided doses.

    • Edema: 250–375 mg daily, adjusted based on response.

    • Altitude sickness: 125–250 mg twice daily, starting a day before ascent.

  • How to take: Swallow whole with water; can be taken with food.

  • Safety tips: Maintain hydration; do not stand up quickly to avoid dizziness.

  • Storage: Store below 25 °C in original packaging, shielded from light/moisture, and safely away from children.

Ingredients

  • Active Ingredient: Acetazolamide (commonly 250 mg per tablet)

  • Inactive Ingredients: May include lactose, maize starch, magnesium stearate, and sodium starch glycolate. Refer to packaging for full details.

Side Effects

Common Side Effects:

  • Increased urination

  • Tingling sensation in hands or feet

  • Taste changes or dry mouth

Serious Side Effects:

  • Severe electrolyte imbalance (e.g., low potassium or sodium)

  • Dehydration or fainting

  • Kidney stones or blood disorders

If any symptoms occur, contact your GP or healthcare provider immediately.

Warnings

  • Contraindications: Allergy to sulfonamides; severe kidney or liver disease; adrenal gland insufficiency.

  • Cautions: Dehydration risk, diabetes, respiratory acidosis, impaired kidney function.

  • Age restriction: Use with caution in the elderly.

  • Pregnancy/Breastfeeding: Only if clearly necessary and closely monitored.

  • Drug Interactions: May interact with digoxin, lithium, diuretics, corticosteroids—monitor closely.

How quickly does Acetazolamide start working?

Acetazolamide typically starts working within 1 to 2 hours after taking a dose. However, this can vary depending on what it’s being used to treat.

Yes, Acetazolamide is commonly prescribed to help prevent and relieve symptoms of altitude sickness. It’s usually taken 1–2 days before ascent and continued during your stay at high altitude.

It depends on the condition being treated. Some people take Acetazolamide short term for altitude sickness, while others use it longer term for conditions like glaucoma or epilepsy. Always follow your doctor’s advice.

It’s best to avoid alcohol, as it may increase the risk of side effects such as dizziness or dehydration. Speak to your doctor or pharmacist for personalised advice.

If you miss a dose, take it as soon as you remember—unless it’s almost time for your next dose. In that case, skip the missed dose and continue as normal. Don’t double up to make up for a missed tablet.

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