title: Effect of acetaminophen on sulfamethazine acetylation in male volunteers.
abstract: The effect of acetaminophen on sulfamethazine N-acetylation by human N-acetyltrasferase-2 (NAT2) was studied in 19 (n=19) healthy male volunteers in two different phases. In the first phase of the study the volunteers were given an oral dose of sulfamethazine 500 mg alone and blood and urine samples were collected. After the 10-day washout period the same selected volunteers were again administered sulfamethazine 500 mg along with 1000 mg acetaminophen. The acetylation of sulfamethazine by human NAT2 in both phases with and without acetaminophen was determined by HPLC to establish their respective phenotypes. In conclusion obtained statistics of present study revealed that acetaminophen significantly (P<0.0001) decreased sulfamethazine acetylation in plasma of both slow and fast acetylator male volunteers. A highly significant (P<0.0001) decrease in plasma-free and total sulfamethazine concentration was also observed when acetaminophen was co-administered. Urine acetylation status in both phases of the study was found not to be in complete concordance with that of plasma. Acetaminophen significantly (P<0.0001) increased the acetyl, free and total sulfamethazine concentration in urine of both slow and fast acetylators. Urine acetylation analysis has not been found to be a suitable approach for phenotypic studies.
authors.affiliation: College of Allied Health Professionals, Directorate of Medical Sciences, Government College University, Faisalabad, Pakistan Department of Biochemistry, University of Agriculture, Faisalabad, Pakistan imtiazmahmoodtahir@gcuf.edu.pk.
authors.forename: I M
authors.initials: IM
authors.lastname: Tahir
authors.affiliation: Department of Biochemistry, University of Agriculture, Faisalabad, Pakistan.
authors.forename: T
authors.initials: T
authors.lastname: Iqbal
authors.affiliation: Department of Chemistry, Government College Women University, Faisalabad, Pakistan.
authors.forename: S
authors.initials: S
authors.lastname: Saleem
authors.affiliation: Department of Biochemistry, University of Agriculture, Faisalabad, Pakistan.
authors.forename: H
authors.initials: H
authors.lastname: Mehboob
authors.affiliation: College of Allied Health Professionals, Directorate of Medical Sciences, Government College University, Faisalabad, Pakistan.
authors.forename: N
authors.initials: N
authors.lastname: Akhter
authors.affiliation: Department of Biochemistry, University of Agriculture, Faisalabad, Pakistan.
authors.forename: M
authors.initials: M
authors.lastname: Riaz
mesh_terms: D000082:Acetaminophen / Q000494:pharmacology*; D000107:Acetylation; D000328:Adult; D001191:Arylamine N-Acetyltransferase / Q000037:antagonists & inhibitors; D006801:Humans; D008297:Male; D013418:Sulfamethazine / Q000378:metabolism*
chemical_list: D000082:Acetaminophen; D013418:Sulfamethazine; D001191:Arylamine N-Acetyltransferase; C478900:NAT2 protein, human
keywords: N-acetyltransferase 2 (NAT2); Pakistan; acetaminophen; acetyl sulfamethazine (AcSMZ); acetylation; slow and fast acetylator; sulfamethazine (SMZ)