Mercaptopurine treatment should be considered in azathioprine intolerant patients with inflammatory bowel disease

• Published in: Alimentary pharmacology & therapeutics Vol. 29; no. 6; pp. 654 - 661
• Main Authors: HINDORF, U., JOHANSSON, M., ERIKSSON, A., KVIFORS, E., ALMER, S. H. C.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 15.03.2009; Blackwell
• Subjects: 6-Mercaptopurine/therapeutic use; Adult; Azathioprine - adverse effects; Biological and medical sciences; Clinical Medicine; Digestive system; Dose-Response Relationship; Dose-Response Relationship, Drug; Drug; Drug Hypersensitivity; Female; Gastroenterologi; Gastroenterology and Hepatology; Gastroenterology. Liver. Pancreas. Abdomen; Humans; Immunosuppressive Agents - therapeutic use; Inflammatory Bowel Diseases - drug therapy; Klinisk medicin; Male; MEDICAL AND HEALTH SCIENCES; Medical sciences; MEDICIN; MEDICIN OCH HÄLSOVETENSKAP; MEDICINE; Mercaptopurine - therapeutic use; Middle Aged; Other diseases. Semiology; Pharmacology. Drug treatments; Stomach. Duodenum. Small intestine. Colon. Rectum. Anus; Treatment Outcome; Antineoplastic agent; Human; Purine derivatives; Thiopurine derivatives; Inflammatory disease; Crohn disease; Treatment; Antimetabolic; Digestive diseases; Intestinal disease; Immunosuppressive agent; Azathioprine; Mercaptopurine; Ulcerative colitis
• ISSN: 0269-2813; 1365-2036; 1365-2036
• DOI: 10.1111/j.1365-2036.2008.03925.x

Summary Background  Adverse drug reactions are a significant reason for therapeutic failure during thiopurine treatment of inflammatory bowel disease. Some smaller series in this patient population have shown that a switch to mercaptopurine may be successful in many cases of azathioprine intolerance. Aim  To assess the long‐term outcome of mercaptopurine treatment in a large patient population with azathioprine intolerance. Methods  We identified 135 patients (74 women; median age 40 years) with Crohn’s disease (n = 88) or ulcerative colitis (n = 47) and reviewed their medical records. Results  A total of 70 patients (52%) tolerated mercaptopurine and were followed up for 736 (362–1080) days; 65 patients discontinued mercaptopurine due to adverse events after 25 (8–92) days. Mercaptopurine was tolerated in 71% (12/17) with hepatotoxicity and in 68% (13/19) with arthralgia/myalgia during azathioprine treatment. Previous abdominal surgery was more common in mercaptopurine intolerant patients [39/65 (60%) vs. 27/70 (39%); P = 0.02] and thiopurine methyltransferase activity was higher in mercaptopurine tolerant patients than in mercaptopurine intolerant patients [13.2 (11.4–15.3) vs. 11.8 (9.6–14.2) U/mL red blood cells; P = 0.04; n = 81]. Conclusions  A trial of mercaptopurine should be considered in azathioprine intolerance, as half of the patients tolerate a switch to mercaptopurine. Patients with hepatotoxicity or arthralgia/myalgia during azathioprine treatment might benefit more often than those with other types of adverse events.