Methazolamide and acetazolamide in acute mountain sickness

Area of Science:

• Altitude sickness research
• Pharmacology of carbonic anhydrase inhibitors

Background:

• Acute mountain sickness (AMS) is a common condition at high altitudes.
• Carbonic anhydrase inhibitors are used to prevent AMS.
• Common side effects include paresthesias.

Purpose of the Study:

• To compare the efficacy of methazolamide and acetazolamide in preventing AMS.
• To assess the side effect profiles of both drugs at high altitude.

Main Methods:

• 20 subjects ascended to 4985 m.
• Drug efficacy and side effects were monitored.
• Blood gases (PaO2, PaCO2) and oxygen saturation were measured.

Main Results:

• Both methazolamide (150 mg/d) and acetazolamide (500 mg/d) were equally effective in preventing AMS symptoms.
• Oxygen saturation and PaO2 levels were similar on both drugs.
• Acetazolamide caused a greater decrease in PaCO2.
• Paresthesias were less frequent with methazolamide at high altitude.

Conclusions:

• Methazolamide is a viable alternative to acetazolamide for AMS prevention.
• Methazolamide may offer a better side effect profile regarding paresthesias at high altitudes.
• Equal effects on blood gases may lead to similar paresthesia incidence.