Potential influence of body weight on the clearance of polymorphically acetylated drugs.

The acetylation clearance of sulfamethazine was found to be significantly dependent upon body weight in both intermediate and rapid acetylators. The correlation between acetylation clearance and body weight was stronger in the rapid acetylator. It is recommended that weight-corrected acetylation clearance values be used when constructing distribution histograms for phenotyping purposes. Within a phenotypic mode, body weight may be useful in providing initial estimates of dosing needs.