Unintentional amitriptyline overdose leading to coma and cardiac conduction impairment in an older adult: A case report

Elderly patients are particularly vulnerable to look-alike/sound-alike medication errors due to physiological differences that alter medication pharmacokinetics and pharmacodynamics. This report presents the case of a 70-year-old woman admitted to the emergency department in an unconscious state. The information provided by the patient's family suggested a potential unintentional amitriptyline overdose due to confusion with berberine-a plant-derived over-the-counter antidiarrheal medication of similar appearance and packaging. Examination of the remaining amitriptyline tablets indicated the patient had likely consumed 19 tablets of 25 mg amitriptyline. This suspicion was supported by an electrocardiogram showing QRS widening to 110 ms and tachycardia. Following serum alkalization therapy with sodium bicarbonate, the patient's consciousness improved, her heart rate normalized, and QRS duration was shortened. This case underscores the importance of involving healthcare providers and family members in implementing robust safety measures to prevent unintentional medication errors caused by look-alike/sound-alike medications, particularly among older adults.