Risk of IBD in Patients Receiving Treatment With Isotretinoin

Ahmed et al present a meta-analysis and systematic review of articles examining the association between isotretinoin therapy for acne and the risk of IBD. Their stated objective is "to clarify this controversy by examining the risk of getting IBD and its two subtypes, Crohn's disease and ulcerative colitis, after isotretinoin usage." Unfortunately, this article only serves to muddy the picture a bit further. Their main conclusion is that patients exposed to isotretinoin for more than 1 year may have an increased risk of developing IBD, whereas the risk is not increased for durations of treatment shorter than 1 year. Although this is reassuring for the standard course of isotretinoin, it adds a new layer of uncertainty for some outliers, and the research letter by Ahmed et al is of insufficient length or depth to clarify some further questions. For example, is the increased risk of IBD dependent on the cumulative dose in treatment courses lasting longer than 1 year? Does the potential increased risk apply to the off-label use of low-dose long-term isotretinoin therapy? Is the purported increased risk of IBD an artifact of the meta-analysis methodology through which the data were combined from differently designed and controlled studies that were not necessarily meant to be combined? Hopefully, further analyses of large databases will answer some or all of these questions.

Given the preponderance of recent reassuring data, including the data from this study, that a standard course of isotretinoin does not increase the risk of IBD, I will continue to counsel my patients to that effect. However, should the rare standard course of isotretinoin therapy be approaching the 1-year mark with any individual patient, I will unfortunately now need to bring up the results of this meta-analysis, and we will discuss whether to continue or take a break from the treatment.