Effect of Acetazolamide on Hypoxemia during Sleep at High Altitude

Abstract

ACUTE exposure to high altitude results in respiratory alkalosis. With time ("acclimatization") blood pH tends to return to normal levels¹; return is hastened by acetazolamide, a carbonic anhydrase inhibitor that slows the hydration of carbon dioxide and increases renal excretion of bicarbonate.² Acetazolamide also lessens the symptoms of acute mountain sickness,^{3 4 5 6} in which insomnia and headache are frequently experienced. Insomnia is associated with increased wakings and periodic breathing or apnea,⁷ and headache is usually worst in the morning upon rising.⁸ Profound hypoxemia often occurs during sleep at high altitude.⁹ To determine whether the beneficial effects of acetazolamide result from . . .