title: Validity of saliva samples for the estimation of dipyrone metabolites pharmacokinetics.
abstract: Plasma and saliva pharmacokinetics of dipyrone (CAS 5907-38-0) metabolites, 4-methylaminoantipyrine (MAA), 4-aminoantipyrine (AA), 4-formylaminoantipyrine (FAA) and 4-acetylaminoantipyrine (AAA), has been studied in 10 healthy volunteers, after oral administration of 1.0 g dipyrone, MAA, AA, FAA and AAA saliva concentrations correlated significantly with the respective plasma concentrations (r = 0.81, r = 0.62, r = 0.83 and r = 0.91, p < 0.001). MAA and AA concentrations in saliva were lower than in plasma while the FAA and AAA saliva concentrations were similar to the respective plasma concentrations. The saliva/plasma concentration ratios were highly dependent on sampling time. The elimination half-life of the final metabolites FAA and AAA can be equally evaluated from plasma and saliva data. For MAA, plasma and saliva t1/2 values were significantly correlated despite a substantial intra-subject difference. No correlation was found for AA plasma and saliva derived pharmacokinetic parameters. Similar to the plasma AAA/AA ratio, the saliva AAA/AA ratio in spot sample 6 h following oral dose might be proven to be a reliable discriminatory index for acetylation phenotyping.
authors.affiliation: Clinical Pharmacology Unit, Hadassah University Hospital, Jerusalem, Israel.
authors.forename: Y
authors.initials: Y
authors.lastname: Caraco
authors.forename: E
authors.initials: E
authors.lastname: Zylber-Katz
authors.forename: L
authors.initials: L
authors.lastname: Granit
authors.forename: M
authors.initials: M
authors.lastname: Levy
mesh_terms: D000107:Acetylation; D000328:Adult; D000632:Aminopyrine / Q000031:analogs & derivatives / Q000493:pharmacokinetics; D000675:Ampyrone / Q000493:pharmacokinetics; D004177:Dipyrone / Q000031:analogs & derivatives / Q000032:analysis / Q000493:pharmacokinetics*; D005260:Female; D006207:Half-Life; D006801:Humans; D008297:Male; D010641:Phenotype; D047069:Pyrazolones; D012463:Saliva / Q000737:chemistry*
chemical_list: D047069:Pyrazolones; D000632:Aminopyrine; D000675:Ampyrone; C011256:4-formylaminoantipyrine; D004177:Dipyrone; C008667:noramidopyrine