A Rare Case of Isoniazid Induced Pancreatitis

Abstract

Acute pancreatitis is a common gastroenterology discharge diagnosis in the US with an annual cost of nearly 2.6 billion dollars1. Medications have been recognized as a potential etiology of acute pancreatitis, but reports of drug induced pancreatitis only range from 0.1%-2% of overall cases2. Isoniazid (INH) is commonly used for treatment of latent mycobacterium tuberculosis (TB) with a relatively low risk of developing pancreatitis. The following is a case report of INH induced pancreatitis. A 47-year-old male with cirrhosis secondary to hepatitis C virus presented to the emergency room (ER) with complaints of abdominal and back pain, nausea, vomiting, and intermittent confusion for 1 day. The patient was recently admitted for hepatic encephalopathy and discharged 7 days prior to this presentation. During that admission the patient was listed for liver transplant and discovered to have latent TB for which he was started on INH therapy. The patient reported feeling well at discharge and compliance with all medications including spironolactone, lactulose, and INH. His labs in the ER revealed a lipase level greater than 1,000 U/L. He denied any history of drinking and was negative for detectable levels of ethanol or phosphatidylethanol on labs. Ultrasound of the liver, pancreas, and biliary system did not reveal any gallstones or biliary duct abnormalities. The INH was held upon admission and the patient received supportive care only. On his second day of hospitalization he was started on rifampin therapy for his latent TB. By day 3 his clinical symptoms had resolved and lipase showed an improvement to 115 U/L, after which he was successfully discharged without any recurrence of symptoms. INH is a first-line drug in the treatment of latent tuberculosis. Severe adverse reactions with INH have been observed including hepatitis, skin rashes, neurologic disturbances, and hematologic alteration3,4. Literature review shows that acute pancreatitis associated with INH develops with a median onset of 16 days after starting therapy5-16. In our case, pancreatitis was diagnosed 8 days after initiation of therapy and clinical and lab abnormalities began to improve within 24 hours of INH discontinuation. Previous documented cases demonstrate up to two weeks of clinical and lab abnormalities in cases where INH was not quickly withdrawn 6. This case demonstrates the importance of strong suspicion for and early recognition of drug induced causes of pancreatitis.1253_A.tif Figure 1: References