Topiramate-induced distal renal tubular acidosis presenting as critical hypokalaemia.

Renal tubular acidosis (RTA) is a group of rare conditions characterised by an acidotic state in the setting of preserved glomerular function. Distal RTA (Type 1) is a subtype that specifically results from impaired hydrogen ion secretion and hypokalaemia due to increased potassium loss in the distal nephron, particularly in the collecting duct.Our case describes the clinical course of a middle-aged woman with epilepsy on topiramate monotherapy who presented acutely with flaccid paralysis, areflexia and global hypotonia secondary to critical hypokalaemia. This case highlights the impact of chronic topiramate use on renal physiology, its ability to induce distal RTA and the potential to cause life-threatening hypokalaemia.