PHARMACOKINETICS OF VANCOMYCIN IN ADULT CYSTIC-FIBROSIS PATIENTS

Although the dispositions of many antibiotics are altered in cystic fi brosis patients, that of vancomycin has not been studied. To assess va ncomycin pharmacokinetics, 10 adult cystic fibrosis patients were give n a parenteral dose of vancomycin (15 mg/kg) during the first 72 h of hospitalization for acute bronchopulmonary exacerbation, Blood samples were obtained at 0, 1, 1.25, 1.5, 2, 3, 4, 6, 8, 12, 15, and 24 h, Th e mean (standard deviation) weight, measured creatinine clearance, and Taussig clinical score were 51 (13) kg, 130 (39) ml/min/1.73 m(2), an d 64 (13), respectively, Multicompartmental pharmacokinetic parameters were best described by a two-compartment model, The mean (standard de viation) volume of distribution, total body clearance, and terminal el imination rate constant were 0,58 (0.15) liter/kg, 91 (19) ml/min/1.73 m(2), and 0.123 (0.05) h(-1), respectively, These values were consist ent with vancomycin pharmacokinetic parameters obtained in previous st udies of healthy adult volunteers. Vancomycin dosages predicted by usi ng a two-compartment Bayesian model were approximately 15 mg/kg every 8 to 12 h, There were poor correlations between clinical score or crea tinine clearance and any pharmacokinetic parameter (r values of < 0.32 ), The coefficient of correlation between urine flow rate and total bo dy clearance was 0.7 (P < 0.05), Adult cystic fibrosis patients exhibi t a disposition of vancomycin similar to that exhibited by healthy adu lts, and thus cystic fibrosis does not alter vancomycin pharmacokineti cs.