Hypokalaemia associated with excessive cola-flavoured drinks consumption

We present a case involving a male patient in his 30s who was admitted to hospital due to recurrent episodes of hypokalaemia over the past 5 years. His medical history revealed hypertension, attention deficit hyperactivity disorder (ADHD), autism, and paranoia. He was taking citalopram, ramipril, amlodipine, and pramipexole. Tests indicated normal levels of aldosterone/renin ratio and plasma metanephrines. On reviewing his dietary history, it was noted that he consumed 3 to 3.5 L of cola-flavoured drinks on a daily basis. Normal potassium levels were achieved after a significant reduction in cola-flavoured drinks intake and potassium replacement. Subsequent outpatient clinic follow-up revealed that normal potassium levels were maintained even after the patient ceased taking potassium replacement tablets. Given the rarity of hypokalaemia associated with fizzy drinks, the underlying mechanism for this association remains unclear. In this case report, we attempt to provide a possible explanation for the involved mechanisms.