2467 Recognizing Macrobid as a Potential Cause for Major Liver Injury

Abstract

INTRODUCTION: Nitrofurantoin is one of the most commonly prescribed antibiotics for urinary tract infections. It is also one of the most common medications known to cause drug-induced liver injury (DILI). Nitrofurantoin can cause acute or chronic liver injury. Acute liver injury occurs within a few weeks of nitrofurantoin use and resolves quickly after discontinuation. Chronic liver injury typically presents months or years after use of nitrofurantoin and can also present as an autoimmune type reaction. This case demonstrates the need to have high suspicion for DILI when patients present with elevated liver enzymes with recent use of nitrofurantoin. CASE DESCRIPTION/METHODS: The patient is a 56 year old female with a past medical history of recurrent urinary tract infections including ESBL who presented with abdominal pain, diarrhea, and nausea for one month. Prior to symptoms onset, she had developed burning and odor in her urine and was treated with nitrofurantoin for 14 days. Urinary symptoms resolved after antibiotic completion. Two weeks later, the patient began to develop worsening abdominal pain that was accompanied by diarrhea and subjective fevers and chills. On presentation, the patient's vitals were found to be: 98.5F, HR 107, 156/74, and saturating well on room air. On labs, she was found to have elevated alkaline phosphatase of 200 U/L, ALT 1014 U/L, AST 2011 U/L, Total Bilirubin 1.0 mg/dL, Lipase 59 U/L, negative alcohol level, negative acetaminophen level, and negative viral hepatitis panel. CT Abdomen and Pelvis showed hepatic steatosis but no acute processes. Secondary workup for liver injury was largely negative except an ANA titer of 1:320. The patient was treated supportively and had a gradual decrease in her liver enzymes over the course of three days. DISCUSSION: DILI can be a difficult diagnosis to make because it is a diagnosis of exclusion. In our case, the patient experienced marked elevations in her liver enzymes that resolved with only supportive care. Her workup was negative and the only identifiable etiology of her acute liver injury was her nitrofurantoin use. Additionally, our patient was seen to have features of drug-induced autoimmune hepatitis with her ANA elevation suggesting a component of chronic liver injury. She had been treated with Nitrofurantoin in past infections as well. Since Nitrofurantoin can cause sometimes severe liver damage, the indication for its use should be evidence-based, and signs/symptoms of liver injury should lead to prompt cessation of therapy.