Methotrexate: prescribing and monitoring practices among the consultant membership of the British Association of Dermatologists.

Abstract

Methotrexate is frequently used in dermatology practice and is potentially toxic. Prescribing and monitoring strategies have evolved over time and many areas of practice remain controversial and without firm evidence base. To document current U.K. prescribing and monitoring practice and to identify variations in practice. A postal questionnaire was sent, in a single mailshot, in January 2004 to the entire consultant membership (n = 531) of the British Association of Dermatologists. We received a response rate of 71%. The majority of respondents prescribed for small numbers of patients and 81% reported using a patient information sheet. Almost all monitored full blood count, liver function tests and urea, electrolytes and creatinine, and 71% measured aminoterminal peptide of type III procollagen levels. We identified a wide range of practice in the use of liver biopsy. In terms of adverse events, 12% reported experience of patients developing irreversible liver damage (severity not defined). Forty-nine deaths were reported, of which 18 were due to myelosuppression, six to possible pulmonary fibrosis, two to liver failure in the absence of reported alcohol consumption and four as a consequence of liver biopsy. We have documented wide variations in methotrexate prescribing and monitoring practice. We compare reported practice with current guidelines and highlight the importance of monitoring for myelosuppression.