How are thiopurines used and monitored by Swedish gastroenterologists when treating patients with inflammatory bowel disease?

Objective. To perform a survey of thiopurine treatment in inflammatory bowel disease (IBD) among Swedish gastroenterologists. Material and methods. A web-based questionnaire consisting of 25 multiple-choice questions was sent to 322 gastroenterologists in adult practice. Results. A total of 132 questionnaires were received giving a response rate of 41%. Thiopurines were used by all 122 gastroenterologists in IBD practice and azathioprine was the first-choice thiopurine among 118 (97%) of them. Almost all gastroenterologists (97%) used weight-based dosing that was gradually escalated. The vast majority (89%) considered that efficacy should be evaluated within 6 months of therapy, while opinions regarding the optimal duration of therapy varied considerably. It was seen that 74% switched thiopurine in case of intolerance to the first-line substance. Thiopurine S-methyltransferase (TPMT) determinations were performed by 74% of the gastroenterologists and 67% used metabolite measurements. TPMT analyzers were more likely to measure metabolites (74 vs. 43%, p = 0.002). A quarter of the respondents were familiar with unconventional immunomodulation (co-administration of allopurinol, 6-thioguanine, mycophenolate mofetil or tacrolimus) and these respondents were also more likely to measure metabolites (79 vs. 52%; p = 0.002). Conclusions. Thiopurines are well established in the treatment of IBD among Swedish gastroenterologists. New and evolving knowledge about thiopurine therapy in IBD has been adapted to a large extent. Whether this change in clinical practice will have an impact on treatment outcomes has yet to be proven.