Thiopurine Metabolites

(6TGN & 6MMPN)


We offer a service to help assess the therapeutic levels of active metabolites of the thioguanine drugs azathioprine, 6-mercaptopurine and  6-thioguanine.

Experience from around the world suggests that demand for this assay will increase. The assay is particularly relevant to determine the correct treatment regimes in patients who have TPMT heterozygous status who exhibit a low TPMT enzyme activity.

Download information leaflet here...



Thiopurine Metabolites


Clinical Biochemistry, City Hospital Birmingham

Specimen Type:

4ml EDTA


4oC prior to posting

Posting Details:

First class post - our laboratory opens post on a Saturday so samples sent on Friday should be handled appropriately.

Posting Address:

Department of Clinical Biochemistry, City Hospital, Dudley Road, Birmingham B18 7QH

Clinical Use:

Assessment of the  therapeutic levels of thioguainine  drugs that are being achieved. Of particular use in patients who are heterozygous for the TPMT enzyme where reduced dose regimes are being used or where it is unclear that therapeutic levels are being achieved.

Special Details:

It is suggested that the  level of 6-TGNs is checked 4 weeks after commencing/changing the  thiopurine drug dose as by this time steady  state levels should have been achieved. Time of sampling need not be related to the  time of administration of the  parent drug.

We assay is run every day.




2 working days, with PDF reporting available

External QA Scheme:

In house QC at present  with  external QA under development

CPA Accredited Lab/Test:



Key Contact:

Jenna Waldron

Tel: 0121 507 5345

Head of Department:

Dr Jonathan Berg

Further information

Please download leaflet:

Download information leaflet: