Myxedema coma precipitated by polypharmacy of risperidone, amiodarone and diazepam – a rare case report

Myxedema coma (MC) is a rare, life-threatening complication of severe hypothyroidism, marked by altered sensorium, hypothermia, respiratory failure, hyponatremia, and hypotension. While commonly triggered by cold exposure and infections, studies show it can also result from medications like Amiodarone (a class III antiarrhythmic), Antipsychotics and very rarely from Benzodiazepines. Our patient, a 77-year-old Hypertensive woman, who had been on chronic Risperidone therapy, was treated with Amiodarone infusion for atrial fibrillation and later received Diazepam for suspected extrapyramidal symptoms. This combination likely pushed an already compromised thyroid function beyond its critical threshold, leading to full-blown myxedema coma. This case report highlights the need for cautious use of antipsychotics, Amiodarone and Benzodiazepines even in subjects not known to be hypothyroid, regular thyroid monitoring in them and effective treatment strategies.