Thiopurine Dosing using Thiopurine Methyltransferase Status: A Systematic Review of Clinical Guidance

Produced by Technology Assessment at SickKids, Hospital for Sick Children.The objective of this study was to conduct a systematic review of clinical guidance documents that recommend TPMT testing prior to the administration of thiopurine drugs. The specific aims were to 1) review the breadth of guidance documents and their sources, and 2) critically appraise the quality of the guidance documents by evaluating the quality of evidence used to support the preferential use of one method (genotyping versus phenotyping) over another and used to guide dose adjustments based on TPMT status.Supported by a program grant from the Ontario Ministry of Health and Long-Term Care Drug Innovation Fun