A 32-year-old male presented with severe palpitations and syncope. He had a history of prior alcohol, opiate, and methamphetamine abuse, but otherwise no known medical conditions. He admitted to taking, over the prior 10 days, up to 200 mg daily of loperamide (maximum recommended dosage 16 mg per day) and multiple doses of famotidine daily (estimated up to 500 mg per day). Both medications were obtained over the counter. He did not take any other medications, supplements, or recreational substances.\nHis initial vital signs were as follows: blood pressure 121/76 mmHg; pulse 62 beats/min; temperature 98 F; and oxygen saturation 97%, breathing ambient air. He appeared disheveled, but otherwise had no abnormal physical exam findings. His presenting electrocardiogram (ECG) showed sinus tachycardia at 101 beats/min, first-degree atrioventricular (AV) block, nonspecific intraventricular conduction delay, and prolonged QT interval (Fig. ). Serum electrolytes, blood counts, cardiac troponin (I), renal, liver, and thyroid function were normal. Transthoracic echocardiogram showed normal chamber size and function and normal valves.\nShortly after admission, he had recurrent symptoms (syncope preceded by palpitations) that occurred during sustained monomorphic VT (Fig. ). VT terminated spontaneously. Loperamide and famotidine were discontinued, and he was treated with intravenous magnesium and supportive care. During hospitalization, he had frequent multifocal premature ventricular complexes and runs of both monomorphic and polymorphic VT. After 5 days, his PR interval, QRS duration, and QT interval normalized and VT resolved. He was discharged and strongly encouraged to abstain from recreational drug use. At 6 months follow-up, he had maintained abstinence from recreational drugs and his ECG continued to be normal (Fig. ).
A 36-year-old male with past medical history of alcohol and polysubstance abuse presented with complaints of leg swelling and dyspnea. On examination he was lethargic with frequent periods of apnea and profound hypoxia (oxygen saturation of 72% on room air). The patient received IV naloxone with improvement in level of consciousness and respiratory rate. EKG demonstrated a prolonged QTc and QRS interval of 592 and 138, respectively. The patient denied any illicit drug use, however admitted to recreational abuse of diphenhydramine and loperamide. Poison control recommended bicarbonate and potassium administration to prevent cardiac arrhythmia. The patient was monitored overnight in the hospital with serial EKGs. Over the next 24 hours his abnormalities on EKG improved as well as his hypoxia. He was discharged home shortly thereafter.