title: Determination of 6-mercaptopurine and azathioprine in plasma by high-performance liquid chromatography.
abstract: Using 1-ml plasma samples, levels of 6-mercaptopurine (6MP) as low as 5 ng/ml and azathioprine (AZA) as low as 40 ng/ml can be detected using a high-performance liquid chromatography reversed-phase column procedure following extraction. Both compounds were stable in frozen plasma for seven weeks. AZA stability in blood was temperature dependent; the half-lives of AZA breakdown to 6MP at 37 degrees were 28 and 46 min in blood drawn from two rhesus monkeys. Plasma levels of 6MP were measured in a rhesus monkey following 6MP (1.47 mg/kg) and AZA (3 mg/kg) intravenous administration. 6MP levels were also measured in three renal transplant patients on daily 50- and 100-mg AZA doses. Peak levels (45-75 ng/ml) were reached within an hour and 6MP levels were detected for up to 7 h.
mesh_terms: D000818:Animals; D001379:Azathioprine / Q000097:blood* / Q000494:pharmacology / Q000627:therapeutic use; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D000882:Haplorhini; D006801:Humans; D008253:Macaca mulatta; D015122:Mercaptopurine / Q000097:blood* / Q000494:pharmacology
chemical_list: D015122:Mercaptopurine; D001379:Azathioprine