Classification of children as slow or rapid acetylators based on concentrations of isoniazid in saliva folowing oral administration of body-weight and surface-area-related dosages of the drug

摘要

The acetylator phenotype of 180 children agedud3-11 years was determined on the basis of isoniazidudconcentrations in saliva collected at 5 hours afterudoral administration of body-weight and surfacearea-udrelated &sages of the drug in a syrup form.udisoniazid 25 mglkg was administered on one occasionudand 75 mg/m2 surface-area on another, withudan interval of 3 days between the occasions. Audcross-over design was employed and the sequenceudwas determined by random allocation. The distributionudof the concentrations was bimodal withudboth procedures, indicating the presence of twoudgroups namely, the slow and rapid acetylators. Theudcriterion for a rapid acetylator was a concentrationudof 0.3 μg/ml or less by body-weight-related dosageudand 0.4 μg/ml or less by that based on surface-area.udBased on these criteria, 62 % of the children wereudclassified as slow acetylators and 38% as rapidudacetylators by body-weight, and 59 and 41 %,udrespectively by surface-area, and the findings wereudsimilar in children in the different age-groups. Theudagreement between the two procedures was 98%.