Thiopurine S-Methyltransferase
TPMT inactivates thiopurine drugs like azathioprine, mercaptopurine, and thioguanine. About 1 in 300 people of European descent has essentially no TPMT activity, and standard doses can cause life-threatening bone marrow suppression in those people within weeks. Intermediate activity affects around 10 percent of people and still requires dose reduction.
Gene2Rx covers 3 medications with published pharmacogenetic guidance for TPMT, drawn from CPIC and FDA sources. Each drug links to its full pharmacogenetics page.
These branded medications include at least one active ingredient whose metabolism or action involves TPMT. Each links to its full pharmacogenetic breakdown.
This page lists drugs affected by TPMT. A Gene2Rx report tells you which metabolizer group you fall into, and what that means for every medication on this list.
Get your report Look up a medicationInformational only, not medical advice. The presence of a TPMT pharmacogenetic guideline does not mean every patient needs to change their dose. Never start, stop, or change a medication without talking to your prescribing clinician.