Short-Term Trial (4 Days) of Acetazolamide in Central Sleep Apnea in Cheyne-Stokes Respiration Due to CHF (Am J Cardiol, 2011) [MEDLINE]: small trial (n = 12)
Acetazolamide Decreased Central Sleep Apneas and Nocturnal Oxygen Desaturation
Acetazolamide Blunted the Chemosensitivity to Hypoxia and Increased the Chemosensitivity to Hypercapnia
In Exercise Testing, Acetazolamide Decreased Workload with No Difference in Peak Oxygen Consumption and an Increment in the Regression Slope Relating Minute Ventilation to Carbon Dioxide Output: suggesting a decrease in ventilatory efficiency
Brain: acetazolamide inhibits the conversion of carbon dioxide to bicarbonate in the brain capillaries, increasing local tissue pCO2 (and decreasing the local pH), resulting in increased central ventilatory drive (in an attempt to decrease the pCO2)
Acetazolamide Has Been Demonstrated to Decrease Cerebrospinal Fluid Bicarbonate in Normal Subjects at Both 3,000 and 14,000 ft altitude (J Appl Physiol, 1968) [MEDLINE]
Kidney: acetazolamide increases renal hydrogen ion retention and increases renal bicarbonate excretion, causing a normal anion gap metabolic acidosis, resulting in increased ventilatory drive
Lung: acetazolamide inhibits the conversion of bicarbonate to carbon dioxide in the pulmonary capillaries, impairing the lung’s ability to excrete carbon dioxide -> in normal patients, minute ventilation will subsequently increase to maintain a normal pCO2
Overall Effects of Acetazolamide in Specific Subsets of Patients
Effect of Acetazolamide in Patients Who are Able to Increase Their Minute Ventilation (Normal Patient): minute ventilation will increase and pCO2 will decrease, since the increased ventilatory drive will exceed the impaired pulmonary excretion of carbon dioxide
Effect of Acetazolamide in Patients Who are Not Able to Increase Their Minute Ventilation (Severe COPD Patient): minute ventilation will not increase and pCO2 will increase due to the impaired pulmonary excretion of carbon dioxide, resulting in respiratory acidosis (Am Rev Respir Dis, 1983) [MEDLINE]
Metabolism
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Administration
PO (Prophylaxis for High-Altitude Illness): 125-250 mg PO BID started 1 day before ascent and discontinued after 2 days at final altitude
IV (Metabolic Alkalosis): 250 mg IV PRN
Dose Adjustment
Hepatic
Renal
Adverse Effects
Hematologic Adveese Effects
Aplastic Anemia (see Aplastic Anemia, [[Aplastic Anemia]]): moderate risk of aplastic anemia
Effect of acetazolamide on acute mountain sickness. N Engl J Med. 1968;279(16):839 [MEDLINE]
Effects of acetazolamide and hypoxia on cerebrospinal fluid bicarbonate. J Appl Physiol. 1968;24(1):17 [MEDLINE]
Relative effectiveness of acetazolamide versus medroxyprogesterone acetate in correction of chronic carbon dioxide retention. Am Rev Respir Dis. 1983;127(4):405 [MEDLINE]
Effects of acute and chronic acetazolamide on resting ventilation and ventilatory responses in men. J Appl Physiol (1985). 1993;74(1):230 [MEDLINE]
Acetazolamide in the treatment of acute mountain sickness: clinical efficacy and effect on gas exchange. Ann Intern Med. 1992;116(6):461 [MEDLINE]
Pathophysiology and epidemiology of chronic mountain sickness. Int J Sports Med. 1992 Oct;13 Suppl 1:S79-81 [MEDLINE]
Acetazolamide: a treatment for chronic mountain sickness. Am J Respir Crit Care Med. 2005;172(11):1427 [MEDLINE]
Andean, Tibetan, and Ethiopian patterns of adaptation to high-altitude hypoxia. Integr Comp Biol. 2006 Feb;46(1):18-24. doi: 10.1093/icb/icj004. Epub 2006 Jan 6 [MEDLINE]
Acetazolamide improves central sleep apnea in heart failure: a double-blind, prospective study. Am J Respir Crit Care Med. 2006;173(2):234 [MEDLINE]
Acetazolamide for Monge’s disease: efficiency and tolerance of 6-month treatment. Am J Respir Crit Care Med. 2008 Jun 15;177(12):1370-6. doi: 10.1164/rccm.200802-196OC. Epub 2008 Apr 3 [MEDLINE]
Effect of acetazolamide on chemosensitivity, Cheyne-Stokes respiration, and response to effort in patients with heart failure. Am J Cardiol. 2011 Jun;107(11):1675-80. Epub 2011 Mar 21 [MEDLINE]
