Methotrexate Hepatotoxicity; the Danger Not to Be Ignored

Methotrexate is used increasingly for treatment of some diseases such as rheumatoid arthritis، psoriasis and Crohn. Bone marrow suppression، mucocutaneous lesions، pneumonitis، and hepatotoxicity are major side effects of this drug. Since methotrexate toxicity is dose dependent and is usually administered with low dose via a weekly regimen، its side effects are not commonly seen. But due to long term prescription of this drug over the recent years especially for rheumatoid arthritis، growing cases of methotrexate hepatotoxicity are referred to Gastroenterologist. High dose of drug، high age، alcohol consumption، renal failure and preexisting liver disease are main risk factors for this toxicity. In this study، in addition to presenting two cases with cirrhosis and two cases with hepatitis linked to methotrexate، the clinical aspects on this field are discussed. Methotrexate hepatotoxicity is not a theoretical issue that can be ignored because it can lead to cirrhosis and liver failure. We can prevent the onset of this growing side effect with appropriate patient selection and investigating the patients’ liver function before and during Methotrexate therapy. Periodic testing the liver enzymes is used for monitoring the liver condition، but because interpretation of these tests is sometimes difficult، liver biopsy is needed in particular cases.