The ten-year single-center experience with 6-mercaptopurine in the treatment of inflammatory bowel disease
Glazier, K.D.; Palance, A.L.; Griffel, L.H.; Das, K.M.
Journal of Clinical Gastroenterology 39(1): 21-26
2005
ISSN/ISBN: 0192-0790 PMID: 15599205 Document Number: 591653
To report the 10-year experience of a single center in treating patients with refractory inflammatory bowel disease (IBD) with relatively lower dose of 6-mercaptopurine (6-MP). The charts of 285 patients with IBD (Crohn's disease 160 and ulcerative colitis 125) receiving 6-MP were reviewed. Clinical response, subsequent breakthrough while taking 6-MP, and relapse rates when 6-MP was discontinued and side effects were assessed. Ninety-three percent of the patients were taking 50 to 75 mg/day of 6-MP. Complete remission was achieved in 62%, partial remission in 14.5%, and failure to achieve remission in 23.5% of the patients. Of complete responders, 27.5% had breakthrough while continuing 6-MP. Nine percent of those that achieved a complete remission experienced a relapse after 6-MP was discontinued. Side effects included leukopenia (11.2%), abnormal liver function tests (3.8%), various infections, including pneumonia (3.1%), pancreatitis (2.5%), nausea (2.1%), headache (2.8%), fever (1.4%), hair loss (1%), and rash (0.7%). Two cancers occurred while taking 6-MP: melanoma on the finger and a fatal colonic lymphoma. Four patients continued 6-MP throughout pregnancies and had normal outcomes. In our experience 6-MP is relatively safe and appears to be as effective at a lower dosage (0.84 mg/kg per day) compared with the recommended higher dosage (1-1.5 mg/kg per day), when leukopenia was more frequent. Serious side effects, although rare, need to be monitored.