2294 The Unusual Wolf in Sheep's Clothing

Abstract

INTRODUCTION: Dronedarone is frequently employed for rhythm control in patients with atrial fibrillation (AF). Chronic therapy with Dronedarone has been associated with mild liver enzymes elevations in up to 12% of patients. There are also several reports of dronedarone induced Acute Renal Failure (ARF) on Adverse Drug Reaction reporting databases worldwide. CASE DESCRIPTION/METHODS: An 86-year-old male with past history of AF, COPD, CKD and HTN presented with 1 day duration of dyspnea and palpitations. He was found to be in AF with rapid ventricular response with a heart rate of 127. Vitals were otherwise stable. He was also suspected to have acute on chronic diastolic CHF likely precipitated by atrial fibrillation. Initial labs were pertinent for creatinine of 2.02 (baseline-1.60). Patient was initially started on Diltiazem drip in the ED which was later discontinued due to an IV site reaction. Upon transfer to the medical floor, Cardiology was consulted who recommended Dronedarone for rhythm control. Patient received a total of 3 doses of Dronedarone but did not cardiovert, therefore electrical cardioversion was performed. He developed fatigue few hours after the cardioversion. Liver function tests (LFTs) one day after the last dose of dronedarone and post cardioversion showed elevated ALT (3155), AST (3930), Alkaline Phosphatase (144), total (2.4) and direct (1.0) bilirubin levels. INR was also high (6.1). Viral hepatitis testing was negative. The patient's course was further complicated by acute renal failure (ARF) with creatinine rising to 5.38. Dronedarone mediated hepatic and renal injury was suspected. Dronedarone was discontinued and supportive measures were initiated. Patient's LFTs and creatinine trended down with improvement of symptoms four days following discontinuation of Dronedarone. Patient was discharged home with complete resolution of hepatic and renal failure noted during outpatient follow up. DISCUSSION: Dronedarone mediated acute liver toxicity is rare. Almost none of the cases involved rapid onset of liver injury after drug initiation, which resolved quickly after cessation of the agent. The onset of injury in reported cases ranged from 2 to 11 months. Besides reports on pharmacovigilance databases, two cases of dronedarone-associated ARF have also been published, one of which required hemodialysis. Only one of these cases reported a combined hepatic and renal failure. Our case is unique due to its early onset and severe features with concurrent involvement of both organ systems.