2009 Southern Regional Meeting Abstracts

Case Report: Drug-induced hepatotoxicity is the most common cause of acute liver failure in the United States. A high index of suspicion is required to diagnose drug-induced liver injury. We present second case of clopidogrel-induced mixed hepatocellular and cholestatic injury confirmed with positive rechallenge test.
A 78-year-old woman was admitted for right upper quadrant abdominal pain and jaundice. Her past history included CAD, GERD, hypertension and gout with no prior liver disease and alcohol use. She was started on aspirin 325 mg/day and clopidogrel 75 mg/day after PCI with drug-eluting stents 3 weeks ago. Her regular medications were valsartan, amlodipine, metoprolol, simvastatin, lansoprazole and allopurinol. On examination, she had stable vital signs with pale conjunctivae and icterus sclera. Abdomen was soft with mild tenderness over right upper quadrant. Her hemoglobin was 8.6 g/dl and creatinine 1.9 mg/dl. LFTs were elevated with AST 179 U/L, ALT 234 U/L, alkaline phosphatase 1011 U/L and bilirubin 7.3 mg/dl. One unit of packed red blood cells was transfused. Clopidogrel, amlodipine, simvastatin and valsartan were discontinued. Patient was started on intravenous fluids. Her hemoglobin, ARF and LFTs improved. Abdominal imaging studies ruled out any obstruction in common bile duct. Clopidogrel was reintroduced on day 5 in view of risk of thrombosis of her drug-eluting stents. LFTs increased rapidly thereafter. Results for infectious mononucleosis and hepatitis A, B and C serology, ANA, anti-smooth muscle antibody, ceruloplasmin, CEA and CA19-9 were negative. Drug-induced liver injury was suspected and clopidogrel was discontinued indefinitely. Liver enzymes after two weeks returned to normal.
Clopidogrel is a well tolerated antiplatelet agent with bleeding, rash, vomiting and diarrhea as common side effects. Clopidogrel-induced hepatotoxicity is a rare complication and is difficult to diagnose in presence of polypharmacy and lack of liver biopsy and rechallenge test. A high clinical suspicion with positive rechallenge test and exclusion of other obvious causes confirmed diagnosis of clopidogrel-induced hepatic injury in our patient.
Physicians should be highly vigilant to diagnose drug-induced liver injury, especially for drugs with rare hepatotoxicity such as clopidogrel.