A 43-year-old female patient with a past medical history of substance use disorder (SUD) was brought to the hospital by emergency medical services (EMS) presenting with multiple episodes of dizziness, shortness of breath, and palpitations. EMS reported ventricular tachycardia (VT) while in transit to the hospital for which she was externally defibrillated 10 times without any resolution of the ventricular arrhythmia. The patient’s past medical history was positive for depression and substance abuse of hydrocodone dating back to 2007. The patient’s husband denied any history of cardiac arrhythmias, structural heart disease, or ischemic heart disease. The patient’s husband denied using any medications, including herbal supplements, but reported drug allergies to amoxicillin and erythromycin. The patient’s social history revealed that she worked at a consignment store and had a history of alcohol and marijuana abuse. The patient’s husband also revealed recreational usage of loperamide at approximately 400 mg in the last 24 hours before the presentation. On physical exam in the emergency department, she appeared to be in moderate distress with pain from the external defibrillations. Her vital signs consisted of an elevated pulse of > 200 beats per minute (bpm), an elevated blood pressure of 157/80, and an increased respiratory rate at 24/minute. The pulmonary exam revealed decreased breath sounds bilaterally with symmetrical chest wall expansion. The cardiovascular exam revealed tachycardia with no murmurs reported. Examination of the head and neck showed moist mucous membranes with no jugular venous distension. The gastrointestinal exam was negative for distention, tenderness, rebound, guarding, hepatomegaly, or splenomegaly. The musculoskeletal exam revealed warm and well-perfused upper and lower extremities free of clubbing, cyanosis, and edema. In the processes of placing the electrocardiogram (EKG) electrodes onto the patient in the emergency room, the patient became unresponsive and the two lead EKG monitors showed polymorphic VT with a heart rate of 220 per minute and blood pressure of 84/58. The patient was immediately defibrillated once again before being sedated, intubated, and started on an amiodarone drip. The patient’s vitals were stabilized for 15 minutes before she went into another episode of polymorphic VT despite the amiodarone drip. The patient underwent synchronized cardioversion, and once her vitals stabilized, she underwent a cardiac catheterization which showed patent coronaries and a normal ejection fraction. The patient got transferred to the Medical Intensive Care Unit (MICU) for continuous monitoring and was started on a lidocaine drip in addition to the amiodarone drip. Her EKG in the MICU is shown below in Figure .\nIn the MICU, the patient continued to have polymorphic VT episodes despite medical management and went in and out of VT episodes approximately 16 times with each episode lasting between 30 seconds to two minutes. Subsequently, the patient had a transvenous cardiac pacer placed which stabilized her vital signs. After 72 hours, the pacer was removed, and the patient remained stable on amiodarone and lidocaine. Transthoracic echocardiogram in the MICU revealed a normal ejection fraction with no valvular abnormality. Serum electrolytes were within normal limits, and the urine drug screen was also negative. After the temporary pacer was removed, the patient subsequently remained in sinus rhythm with a heart rate of 70 bpm, QRS duration of 98 ms, and a QTc interval of 456 ms as seen in Figure .\nAfter five days of hospitalization, the effects of the loperamide had completely resolved, and the patient remained in normal sinus rhythm on amiodarone until discharge and followed up a month later.
A 29-year-old female with history of heroin abuse and depression presented after being found altered and confused. At the time, the patient was known to be taking an estimated 300 tablets of loperamide daily for “chronic stomach issues” (1 tablet is 2 mg for an approximate total of 600 mg). Her husband reported that within the past year, he would witness her taking at least one entire bottle of loperamide with roughly 96 tablets up to 3 times per day. There were no other medications reported, including use of any antidepressants.\nOn presentation, she was tachycardic to 156 BPM (beats per minute) and hypotensive to 70/40 mm Hg. Initial electrocardiogram (ECG) showed polymorphic VT with prolonged QTc of 669 ms ( and ). Subsequently, she developed recurrent episodes of VT that degenerated into torsades de pointes, resulting in multiple cardioversions and her admission to the cardiac intensive care unit.\nPreliminary laboratory findings were unremarkable except for the following: leukocytosis 18 bil/L, anion gap 16, and lactate 2.2 mmol/L. Chemistries showed a sodium 136 mmol/L, potassium 4.3 mmol/L, calcium 2.2 mmol/L, and magnesium 1.6 mmol/L. Urine drug screen was positive for cannabinoids, and her chest X-ray was normal. A serum loperamide level was ordered but would not result until after her discharge.\nAfter cardioversion in the emergency room, the patient was stabilized. Repeat ECG shortly after demonstrated a QTc of 515 ms. Poison control was contacted immediately and recommended supportive management. Unfortunately that evening, she began having frequent episodes of nonsustained VT triggered by positional change and vomiting (). Additional intravenous magnesium sulfate was given but symptoms persisted. A sodium bicarbonate infusion at 150 mEq/h was initiated per the recommendations of the electrophysiologist on call.\nSeveral hours later, the patient further decompensated into sustained VT. Electrical cardioversion with 120 J was required to maintain hemodynamic stability. Given her tenuous status and recurrent VT storm, she was intubated and sedated to suppress sympathetic overstimulation. Subsequently, an isoproterenol infusion was started at 2 µg/min to reduce the number of subsequent VT episodes.\nAfter 8 hours without VT, isoproterenol was reduced to 1 µg/min and the bicarbonate infusion was discontinued. Her transthoracic echocardiogram was completed and shown to be normal. Isoproterenol was stopped on day 3, and the patient was extubated. By then, she was free of VT for more than 24 hours and her QTc improved to 500 ms. No additional anti-arrhythmics were started, and the patient was downgraded and later discharged from the hospital ().\nThe final results of her serum loperamide and desmethyl loperamide (the primary metabolite of loperamide) were elevated to 26 ng/mL (normal is <10 ng/mL) and 160 ng/dL (normal is <20 ng/dL), respectively.