No conflict of interest was declared.
Thiopurine drug adverse effects in a population of New Zealand patients with inflammatory bowel disease†
Article first published online: 6 JAN 2004
Copyright © 2003 John Wiley & Sons, Ltd.
Pharmacoepidemiology and Drug Safety
Volume 13, Issue 8, pages 563–567, August 2004
How to Cite
Gearry, R. B., Barclay, M. L., Burt, M. J., Collett, J. A. and Chapman, B. A. (2004), Thiopurine drug adverse effects in a population of New Zealand patients with inflammatory bowel disease. Pharmacoepidem. Drug Safe., 13: 563–567. doi: 10.1002/pds.926
- Issue published online: 11 AUG 2004
- Article first published online: 6 JAN 2004
- Manuscript Accepted: 4 NOV 2003
- Manuscript Revised: 13 OCT 2003
- Manuscript Received: 12 JUL 2003
- inflammatory bowel disease;
- drug toxicity;
- thiopurine drugs
The thiopurine drugs, azathioprine and 6-mercaptopurine are effective in the treatment of inflammatory bowel disease (IBD). However, their use is limited by serious adverse effects that can lead to cessation of therapy. The incidence of these adverse effects has been reported to be approximately 9% but in Christchurch it was felt that the incidence was higher.
We searched our letter database to identify all patients with IBD who had received a thiopurine drug between 1996 and 2002. The case notes were then reviewed to identify those patients who had suffered an adverse effect that required cessation of the drug.
From a total of 216 patients with IBD taking a thiopurine drug, 56 (25.9%) had an adverse reaction requiring cessation of the drug. Adverse effects included allergic-type (25%), liver test abnormalities (34%), nausea/vomiting (6%), bone marrow suppression (7%), pancreatitis (7%) and other (9%). Males were significantly more likely than females to have an allergic-type reaction (p=0.003). All adverse effects resolved with cessation of the drug, with a median of 7 days to resolution. Of the patients with liver test abnormalities on azathioprine, most were able to tolerate 6-mercaptopurine, however challenge with 6-mercaptopurine was not successful for most other patients.
In Canterbury, New Zealand, patients with IBD have a high rate of therapy-limiting adverse effects to thiopurine drugs. There is a significant gender bias for allergic-type adverse effects. Mechanisms for both these observations are not clear. Copyright © 2004 John Wiley & Sons, Ltd.