Articles: mercaptopurine.
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Multicenter Study Comparative Study
Thiopurine methyltransferase and thiopurine metabolite testing in patients with inflammatory bowel disease who are taking thiopurine drugs.
Thiopurine methyltransferase genotyping and thiopurine metabolite testing has been established as an adjunct to monitoring patients taking thiopurine drugs. This special report describes the clinical implications for this type of testing for patients with inflammatory bowel disease who are taking thiopurine drugs. A total of 10% of patients were found to be intermediate metabolizers and the mean dosage (in mg/kg equivalent) was lower in intermediate metabolizers than extensive metabolizers. ⋯ Despite considerable study of thiopurine methyltransferase testing in the literature, it is still not widely used in many geographical areas. This study adds to the evidence about using such testing as well as expanding the role of simultaneously measuring thiopurine metabolites. Further work is planned to evaluate the uptake when such testing becomes available locally as a clinical service.
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6-Mercaptopurine and its prodrug azathioprine are effective for the treatment of inflammatory bowel disease. Thiopurine methyltransferase is important for the metabolism of thiopurines. However, there is controversy as to the clinical utility of measuring thiopurine methyltransferase enzyme activity and 6-thioguanine nucleotide levels. Our aim was to determine if thiopurine methyltransferase enzyme activity and 6-thioguanine nucleotide level monitoring would predict response to therapy with thiopurines in patients with inflammatory bowel disease. ⋯ Thiopurine methyltransferase activity inversely correlated with clinical response to thiopurine treatment in inflammatory bowel disease. Thiopurine methyltransferase enzyme activity below 30.5 U combined with a post-treatment 6-thioguanine nucleotide level > 230 pmol/8 x 10(8) erythrocytes was the best predictor of response.
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Am. J. Gastroenterol. · Nov 1975
Comparative Study Clinical Trial Controlled Clinical TrialResponses to drug therapy in ulcerative colitis. Evaluation by rectal biopsy and histopathological changes.
To evaluate responses to medical therapy in ulcerative colitis, rectal biopsies of patients with active untreated disease, individuals with positive and negative sigmoidoscopic findings treated with salicylazosulfapyridine, prednisone and 6-mercaptopurine, alone and in combinations and noncolitis controls were compared histologically. Predominant histological observations were analyzed statistically. There were fewer crypt abscesses but more mucosal edema after all forms of therapy. Quantitative histopathological analysis failed to demonstrate that the response to one drug was significantly different from another.
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Randomized Controlled Trial Comparative Study Clinical Trial
Interrupted vs. continued maintenance therapy in childhood acute leukemia.
A total of 313 patients with childhood acute leukemia received a combination of vincristine (2 mg/m2/week) and prednisone (60 mg/m2/day); 86% of 276 evaluable patients achieved a complete bone marrow remission in a median of 35 days. When a complete bone marrow remission was achieved, patients were randomized to one of three oral maintenance therapies: 6-mercaptopurine (6MP) (75 mg/m2/day), methotrexate (MTX) (25 mg/m2/twice weekly), or cyclophosphamide (CYC) (100 mg/m2/day). ⋯ The median lengths of subsequent marrow remissions for patients receiving maintenance therapy for 6 months and randomized to continue vs. discontinue were: 57 vs. 17 weeks for 6-MP patients; 60 vs. 40 weeks for MTX patients; and 23 vs. 10 weeks for CYC patients. Results indicate a significant advantage for continuing maintenance therapy at 2 and 6 months after the start of complete bone marrow remission.
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A total of 114 previously untreated patients with myeloblastic leukemia was included in a sequential therapy protocol. Daunorubicin, vincristine, and prednisone were employed for the first 3 weeks, followed by two or more 5-day courses of cytosine arabinoside and 6-mercaptopurine; there was a 5-day rest between courses. Maintenance therapy was as follows: the continuing 6-mercaptopurine and methotrexate treatment was interrupted every 30 days for sequential reinforcement courses consisting of one dose of daunorubicin and vincristine and 7 days of prednisone, or by a 5-day course of cytosine arabinoside plus 6-mercaptopurine. ⋯ The median duration of complete remission was 8 months: 12 months in children and 5 months in adults. The over-all survival rate was 4 months: 13 months for patients with complete remission, 4 months for those with partial remission, and 1 month for patients who did not respond to therapy. The difference in survival of those with complete remission and all the others was significant (p less than 0.01).