What counseling is required before prescribing acetazolamide (Diamox) for altitude sickness prevention?

From the Guidelines

Before prescribing acetazolamide for altitude sickness prevention, patients should be thoroughly counseled on its potential side effects, proper usage, and the importance of concurrent acclimatization measures. When considering acetazolamide for altitude sickness prevention, it's crucial to weigh the benefits against potential risks, especially in individuals with pre-existing conditions that could be exacerbated by the medication 1.

Key Counseling Points

• Patients should be informed about the typical dosage of acetazolamide, which is 125-250 mg twice daily, starting 24-48 hours before ascent and continuing for 48 hours after reaching the target altitude.
• Side effects such as increased urination, tingling in extremities, altered taste, and potential fatigue should be discussed 1.
• The mechanism of action of acetazolamide, which involves increasing ventilation and reducing alkalosis through carbonic anhydrase inhibition, should be explained to patients.
• It's essential to emphasize that acetazolamide does not replace proper acclimatization and that patients should still follow gradual ascent protocols, stay hydrated, and avoid alcohol.
• Patients should be aware of the symptoms of altitude sickness and understand that severe symptoms require immediate descent regardless of medication use.

Special Considerations

• Individuals with certain medical conditions, such as kidney or liver disease, should be carefully evaluated before starting acetazolamide due to potential interactions or exacerbations 1.
• Patients should also be advised about the potential for a transient myopic shift as a side effect of acetazolamide and have proper corrective measures in place 1.
• The importance of recognizing and managing high altitude retinopathy (HAR) and non-arteritic ischemic optic neuropathy (NAION), which can occur at high altitudes, should be discussed with patients 1.

From the FDA Drug Label

The FDA drug label does not answer the question.

From the Research

Counseling Requirements for Acetazolamide Prescription

Before prescribing acetazolamide (Diamox) for altitude sickness prevention, the following counseling points should be considered:

• The patient should be informed about the proper dosing schedule, with studies suggesting that starting acetazolamide 12 to 24 hours before ascent is effective in preventing acute mountain sickness (AMS) 2.
• The patient should be aware of the potential side effects of acetazolamide, which can be dose-related, and that lower doses may offer adequate protection with fewer side effects 3, 2.
• It is essential to discuss the importance of ascending to high altitudes gradually and the need to monitor for symptoms of AMS, such as headache, ataxia, and sudden loss of strength 4.
• Patients should be advised to seek medical attention immediately if they experience severe symptoms or if their condition worsens despite taking acetazolamide.
• The patient should be informed about alternative treatments, such as dexamethasone, which may be used for those with sulfa intolerance or as an alternative to acetazolamide 2.

Key Considerations

• Acetazolamide is the most common medication used for prevention of AMS, and its efficacy has been demonstrated in several studies 5, 3, 2.
• The optimal timing for starting acetazolamide is still a topic of debate, with some studies suggesting that starting it the day before ascent may be more effective than starting it on the day of ascent 5, 6.
• Patients should be aware of the potential risks and benefits of acetazolamide and the importance of proper usage to minimize side effects and maximize efficacy 3, 2.