Two weeks after starting oral acetazolamide for elevated intraocular pressure, a patient reports tingling around the mouth and in the fingertips, generalised malaise, and loss of appetite. The most likely explanation for these symptoms is:

• A Hypokalaemic alkalosis from renal potassium wasting
• B Hypernatraemia caused by free water retention
• C Hypoglycaemia secondary to pancreatic beta cell stimulation
• D Systemic metabolic acidosis from bicarbonate diuresis ✓

Explanation

Acetazolamide causes renal excretion of bicarbonate along with sodium and potassium, producing a hyperchloraemic metabolic acidosis. The classic paraesthesiae, fatigue, anorexia, and metallic taste reflect this acidotic state. Alkalosis (option A) is the opposite disturbance and occurs with loop diuretics, not carbonic anhydrase inhibitors. This is a standard examination point: acetazolamide gives acidosis while thiazides and loops give alkalosis.

Reference: Katzung's Basic and Clinical Pharmacology, 15th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.