RESUMO
Clindamycin is an antimicrobial agent metabolized by CYP3A4. Gender may influence the pharmacokinetics of drugs metabolized by this pathway, however, no information about differences in the pharmacokinetics of clindamycin in men and women is available. The purpose of this study was to evaluate gender differences in clindamycin oral pharmacokinetics. Twenty-four subjects (11 men and 13 women) received an oral 600 mg dose of clindamycin under fasting conditions and plasma concentrations were obtained at selected times during 12 h. Increased plasma levels were observed in women, but when the dose was normalized by the body weight of individuals, these differences disappeared, indicating that gender does not play an important role in the pharmacokinetics of this drug.
Assuntos
Antibacterianos/farmacocinética , Clindamicina/farmacocinética , Citocromo P-450 CYP3A/metabolismo , Administração Oral , Adulto , Antibacterianos/administração & dosagem , Peso Corporal , Clindamicina/administração & dosagem , Feminino , Humanos , Masculino , Fatores SexuaisRESUMO
The current requirement of the Mexican Authorities to demonstrate the interchangeability of ranitidine formulations is to establish that the dissolution profile of the drug shows similarity. In order to establish if this requirement is adequate, the bioavailability of two formulations that did not meet this similarity were compared. Twenty-five female volunteers received 150 mg ranitidine (Azantac or Midaven) under fasting conditions in two separate sessions using a cross-over design. Plasma samples were obtained at selected times for a period of 12 h and stored frozen at -80 degrees C until analysed. Ranitidine plasma levels were determined and pharmacokinetic parameters were obtained. Values (mean+/-SEM) were: Cmax 528.85+/-25.34 and 563.03+/-33.25 ng/ml, tmax 2.76+/-0.19 and 2.79+/-0.18 h, and AUC12 h 2694.94+/-99.50 and 2648.51+/-133.38 ng.h/ml, for Azantac or Midaven, respectively. No statistically significant difference was obtained in the parameters evaluated. Moreover, 90% confidence limits were 96.6%-116.2% and 90.7%-105.1% for Cmax and AUC12 h ratios, respectively, indicating that the formulations tested are bioequivalent, despite the dissimilarity in the dissolution profile of the formulations. These results suggest that the comparative dissolution profile is not an adequate test to demonstrate the interchangeability of ranitidine formulations.