... Why get tested?
To detect patients who are at risk of developing severe side effects if treated with the class of thiopurine drugs that includes azathioprine, mercaptopurine, and thioguanine

When to get tested?
Prior to thiopurine drug treatment

Sample required?
A blood sample drawn from a vein in your arm
...
Lab Tests Online - more...

Thiopurine methyltransferase, drawn from PDB 2BZG. Thiopurine methyltransferase or thiopurine S-methyltransferase (TPMT) is an enzyme (EC 2.1.1.67) that methylates thiopurine compounds. The methyl donor is S-adenosyl-L-methionine, which is converted to S-adenosyl-L-homocysteine. Pharmacology TPMT is best known for its role in the metabolism of the drugs 6-mercaptopurine, azathioprine and 6-thioguanine. Diagnostic use Measurement of TPMT activity is encouraged prior to commencing ...
Wikipedia - [full article]

Resources

  • TPMT (Lab Tests Online)