title: Population pharmacokinetics of azithromycin in whole blood, peripheral blood mononuclear cells, and polymorphonuclear cells in healthy adults.
abstract: Azithromycin's extensive distribution to proinflammatory cells, including peripheral blood mononuclear cells (PBMCs) and polymorphonuclear cells (PMNs), may be important to its antimicrobial and anti-inflammatory properties. The need to simultaneously predict azithromycin concentrations in whole blood ("blood"), PBMCs, and PMNs motivated this investigation. A single-dose study in 20 healthy adults was conducted, and nonlinear mixed effects modeling was used to simultaneously describe azithromycin concentrations in blood, PBMCs, and PMNs (simultaneous PK model). Data were well described by a four-compartment mamillary model. Apparent central clearance and volume of distribution estimates were 67.3 l/hour and 336 l (interindividual variability of 114 and 122%, respectively). Bootstrapping and visual predictive checks showed adequate model performance. Azithromycin concentrations in blood, PBMCs, and PMNs from external studies of healthy adults and cystic fibrosis patients were within the 5th and 95th percentiles of model simulations. This novel empirical model can be used to predict azithromycin concentrations in blood, PBMCs, and PMNs with different dosing regimens.
authors.affiliation: Division of Pharmacotherapy and Experimental Therapeutics, University of North Carolina Eshelman School of Pharmacy, Chapel Hill, North Carolina, USA.
authors.forename: M R
authors.initials: MR
authors.lastname: Sampson
authors.affiliation: 1] Division of Pharmacotherapy and Experimental Therapeutics, University of North Carolina Eshelman School of Pharmacy, Chapel Hill, North Carolina, USA [2] Clinical Pharmacology Modeling and Simulation, GlaxoSmithKline, Research Triangle Park, North Carolina, USA.
authors.forename: T P
authors.initials: TP
authors.lastname: Dumitrescu
authors.affiliation: Division of Pharmacotherapy and Experimental Therapeutics, University of North Carolina Eshelman School of Pharmacy, Chapel Hill, North Carolina, USA.
authors.forename: K L R
authors.initials: KL
authors.lastname: Brouwer
authors.affiliation: Clinical Pharmacology Modeling and Simulation, GlaxoSmithKline, Research Triangle Park, North Carolina, USA.
authors.forename: V D
authors.initials: VD
authors.lastname: Schmith