What is the dosage of Diamox (acetazolamide)?

From the Guidelines

The recommended dosage of Diamox (acetazolamide) is 250-500 mg twice a day, with the option to titrate the daily dose up, as this is a popular starting dose with the majority of clinicians 1. When considering the dosage of Diamox, it's essential to weigh the benefits against the potential side effects, which can include increased risk of diarrhoea, dysgeusia, fatigue, nausea, paraesthesia, tinnitus, vomiting, depression, and rarely renal stones 1.

Key Considerations

• The maximal dose used in the IIHTT study was 4 g daily, but the majority of participants tolerated 1 g/day, and 44% achieved 4 g/day 1.
• A significant proportion of patients (48%) discontinued acetazolamide at mean doses of 1.5 g due to side effects, as identified by Ball et al 1.
• There is no consensus on the use of normal release versus modified release acetazolamide 1.

Clinical Implications

• Patients should be warned about the potential adverse side effects of acetazolamide and monitored closely for any signs of intolerance.
• The dosage of Diamox may need to be adjusted based on individual patient response and tolerance.
• It's crucial to assess kidney function before starting treatment with Diamox, as it is contraindicated in severe kidney disease.

Dosage Titration

• The daily dose of Diamox can be titrated up based on patient response and tolerance, with the goal of achieving optimal therapeutic effects while minimizing side effects.
• Regular follow-up and monitoring are essential to ensure the safe and effective use of Diamox.

From the FDA Drug Label

DOSAGE AND ADMINISTRATION The dosage employed in the treatment of chronic simple (open-angle) glaucoma ranges from 250 mg to 1 g of acetazolamide per 24 hours, usually in divided doses for amounts over 250 mg. In treatment of secondary glaucoma and in the preoperative treatment of some cases of acute congestive (closed-angle) glaucoma, the preferred dosage is 250 mg every four hours, although some cases have responded to 250 mg twice daily on short-term therapy The suggested total daily dose is 8 to 30 mg per kg in divided doses. Although some patients respond to a low dose, the optimum range appears to be from 375 to 1000 mg daily For diuresis in congestive heart failure, the starting dose is usually 250 to 375 mg once daily in the morning (5 mg/kg) Recommended dosage is 250 to 375 mg of acetazolamide once a day for one or two days, alternating with a day of rest

The dosage of Diamox (acetazolamide) varies by condition:

• Glaucoma: 250 mg to 1 g per 24 hours, usually in divided doses
• Epilepsy: 8 to 30 mg per kg per day in divided doses, with an optimum range of 375 to 1000 mg daily
• Congestive Heart Failure: 250 to 375 mg once daily in the morning
• Drug induced Edema: 250 to 375 mg once a day for one or two days, alternating with a day of rest 2

From the Research

Dosage of Diamox (Acetazolamide)

The dosage of Diamox (acetazolamide) can vary depending on the indication and patient population.

• For hospitalized patients, dosages range from 250 to 4,000 mg daily divided every 6-12 hours 3.
• For the prevention of acute mountain sickness, a dosage of 250 mg daily is recommended 4.
• For the prevention of high-altitude illness, a dosage of 125 mg every 12 hours is highly effective 5.
• For the treatment of epilepsy, dosages of 125-250 mg, three to four times a day, are recommended 6.
• For the prevention of acute mountain sickness, day of ascent dosing of acetazolamide 125 mg twice daily has been evaluated, with results showing a higher incidence of AMS compared to traditional dosing, but similar rates of severe AMS and overall symptom severity 7.

Administration Considerations

It is important to note that acetazolamide is highly protein bound and primarily eliminated by the kidneys, so administration should not be more frequent than every 12 hours if creatinine clearance is less than 50 mL/min 3.

Plasma Half-Life

The plasma half-life of acetazolamide is 4-8 hours, though the pharmacologic effects last longer 3.

Potential Benefits

The potential benefits of acetazolamide include ventilator weaning for chronic obstructive pulmonary disease patients, avoidance of invasive procedures in patients with a CSF leak or elevated ICP, and prevention of high-dose methotrexate toxicity and contrast-induced nephropathy 3.