A man in his 80s with a remote history of renal transplant was admitted to hospital for the treatment of Escherichia coli bacteremia and pyelonephritis. He had ischemic cardiomyopathy and had undergone coronary artery bypass grafting several years prior. He had well-controlled diabetes, hypertension, dyslipidemia, and gastroesophageal reflux disease. His medications included tacrolimus, mycophenolate mofetil, aspirin, pravastatin, and pantoprazole. In hospital, appropriate antibiotics were initiated with resultant clinical improvement. One day prior to his discharge to a rehabilitation facility he complained of difficulty sleeping and was seen overnight by the on-call physician. A low dose (12.5 mg) of quetiapine was administered for insomnia. The next morning the patient was found unresponsive with a Glasgow coma scale of 8, without focal deficits on neurological examination. His pupils were equal and reactive, he was afebrile, and his vital signs were within normal limits.