Is isoniazid safe for liver transplant candidates with latent tuberculosis?

Isoniazid (INH) is recommended for tuberculosis prophylaxis in non-liver transplant recipients. However, there is a great reluctance to prescribe this agent for liver transplant candidates and recipients due to the risk of precipitating further hepatic decompensation. We analyzed the records of liver transplantation candidates undergoing a purified protein derivative (PPD) test (tuberculosis skin test) between 2008 and 2010. Patients with no respiratory symptoms, PPD test > 10 mm, and normal chest radiography were diagnosed as latent tuberculosis and prescribed INH (300 mg) per day for 6 months. The 191 patients submitted to a PPD test and those on tuberculosis prophylaxis underwent blood tests and clinical evaluations monthly to detect hepatotoxicity of patients The 33 subjects (17.2%) with a PPD test ≥ 10 mm displayed an average model for end-stage liver disease score of 20 (range: 9-29) and child-Pugh A/B score. The main causes for liver disease were chronic hepatitis C, hepatocellular carcinoma, and alcohol abuse. Among 27 patients who received INH, 18 (66.6%) completed 6 months of prophylaxis. Eight who had shorter treatment courses of 2 to 4 months had undergone transplantation. One patient had to stop treatment because of clinical decompensation due to spontaneous bacterial peritonitis without a transaminases elevation. Six patients did not receive INH: previous tuberculosis treatment, transplantation before initiating prophylaxis, or removal from the liver candidacy list. No patient showed clinical decompensation or laboratory abnormalities associated with use of INH. The average values of alanine aminotransferase pre- and posttreatment were similar (69 and 72 U/l respectively), demonstrating that tuberculosis prophylaxis with INH was safe for liver transplant candidates.