Acetazolamide is being prescribed to a 55-year-old man with glaucoma. Which comorbidity in his history is a relative contraindication because the drug may precipitate hepatic encephalopathy?

• A Chronic hepatitis C cirrhosis ✓
• B Type 2 diabetes mellitus
• C Previous calcium oxalate kidney stone
• D Well controlled asthma

Explanation

Acetazolamide produces systemic metabolic acidosis and alkaline urine. In cirrhosis, the alkaline urine traps ammonium ion poorly and the systemic acidosis increases the fraction of ammonia that crosses the blood brain barrier, both favoring hepatic encephalopathy, so it is avoided in significant liver disease. Diabetes and prior stones do not create this specific hazard.

Reference: Katzung Basic and Clinical Pharmacology, 16th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.