BACKGROUND AND AIMS High concentrations of methylated thiopurine metabolites, such as 6-methyl mercaptopurine, are associated with hepatotoxicity during administration of the conventional thiopurines azathioprine or 6-mercaptopurine in IBD patients. Metabolization of the non-conventional thiopurine 6-thioguanine does not generate 6-methyl mercaptopurine. Hence, the aim of our study was to evalu...

BACKGROUND Phase II biotransformation reactions (also 'conjugation reactions') generally serve as a detoxifying step in drug metabolism. Phase II drug metabolising enzymes are mainly transferases. This review covers the major phase II enzymes: UDP-glucuronosyltransferases, sulfotransferases, N-acetyltransferases, glutathione S-transferases and methyltransferases (mainly thiopurine S-methyl tran...

BACKGROUND The thiopurine drugs, azathioprine and mercaptopurine (MP), are established treatments for IBD. However, therapeutic failure caused by adverse drug reactions occurs frequently. AIM To study combination of allopurinol with reduced-dose thiopurine in an attempt to avoid adverse drug reactions in the treatment of IBD. METHODS Patients with drug reactions to full-dose thiopurines wer...

Acute lymphoblastic leukemia (ALL) is an aggressive hematological tumor resulting from the malignant transformation of lymphoid progenitors. Thiopurine is a widely used drug in the maintaining treatment of ALL. After a period of chemotherapy, 20% of pediatric patients and over 50% of adult patients will relapse. To investigate the mechanisms of drug resistance in vitro, we established the thiop...

In 1995 a report in the New England Journal of Medicine on medication use and risk of Stevens-Johnson syndrome/ toxic epidermal necrolysis (SJS/TEN) identified carbamazepine as a drug with a higher excess risk than most other drugs known to be associated with this severe muco-cutaneous drug reaction. Since then, pharmacogenomics (the study of the role of inherited and acquired genetic variation...

Background: 6-Mercaptopurine (6-MP), a widely used anti-metabolite for the maintenance phase of childhood acute lymphoblastic leukemia (ALL), has been observed to cause myelotoxicity due genetic polymorphism thiopurine methyl transferase (TPMT), one drug-metabolizing enzymes. This study aimed determine frequency S-methyl (TPMT) polymorphic variants in group Pakistani children with (ALL) using 6...

BACKGROUND Individuals with low activity of a key metabolic enzyme, thiopurine methyl transferase (TPMT), are more susceptible to azathioprine-induced myelosuppression. AIM To determine the pattern of use of TPMT activity estimation, with respect to azathioprine use, by medical practitioners in the UK. DESIGN Retrospective analysis of assay use. METHODS We analysed all test results (n=329...

The thiopurine antimetabolites 6-thioguanine and 6-mercaptopurine are important chemotherapeutic drugs in the treatment of childhood acute lymphoblastic leukaemia. Measurement of metabolites of these thiopurines is important because correlations exist between levels of these metabolites and the prognosis in childhood acute lymphoblastic leukaemia. The reversed-phase method for the determination...

aim :  to evaluate the association of dnmt1 and mgmt amino acid substitution polymorphisms and colorectal cancer in iranian population. background : the mgmt and dnmt1 are two important methyltransferase enzymes. amino acid substitution polymorphisms in mgmt and dnmt1 genes may be associated with the genetic susceptibility to sporadic colorectal cancer. patients and methods : we assessed eight ...