When Treatment Becomes the Trigger: Fludrocortisone-Associated Hypokalaemia in an Older Adult.

Hypokalaemia is a common electrolyte abnormality in older adults and is frequently multifactorial in origin. Although often mild and asymptomatic, severe hypokalaemia can result in significant neuromuscular and cardiac complications. Medication-induced hypokalaemia remains an important and potentially reversible cause, particularly in frail elderly populations. We present the case of an 85-year-old woman who presented with generalised weakness, muscle cramps, reduced mobility, and a fall, and was found to have significant hypokalaemia in the context of long-term fludrocortisone therapy prescribed for postural hypotension. Following intravenous potassium replacement and discontinuation of fludrocortisone, with initiation of midodrine as an alternative therapy, the patient's potassium levels normalised and her symptoms improved. This case highlights the importance of medication review and regular electrolyte monitoring in older adults, particularly those receiving mineralocorticoid therapy.