The authors of a recent case report (JPGN 2014; 59: 22-24) note that there has been “only 1 study on the pediatric use of allopurinol in inflammatory bowel disease.” A previous post on this blog has reviewed the use of allopurinol for IBD and provided several references –mainly from use in adults (Data on Allopurinol | gutsandgrowth).
This current study reports on three cases. In all three cases the combination of allopurinol with low-dose 6-mercaptopurine resulted in clinical remission, including one patient which was poorly responsive to infliximab. In all three cases, frequent thiopurine metabolites were obtained to help guide dosing. Prior to allopurinol, all 3 patients had a 6-MMP/6-TG ratio >20; with use of allopurinol there was a decrease in this ratio.
Among these patients, one developed mild leukopenia which resolved with medication adjustment.
Bottomline: Allopurinol can be effective in optimizing thiopurine treatment, but need to be administered carefully. More studies on its use are needed.