Antimicrobial drug concentrations and sampling techniques in the equine lung

The distribution of antimicrobial drugs in the equine lung is important in designing optimal dosage regimens for the treatment of lower airway infections. Several studies in horses and other species have shown that the pharmacokinetics of a drug in the lung cannot necessarily be predicted by its behaviour in plasma, and influencing factors include the class of drug, the animal species and the chosen sampling technique. This review provides a description of the target site for bacterial lower airway infections and describes the penetration of antibiotics into lung matrices. It also offers an overview of published equine pulmonary pharmacokinetic studies and considers the different sampling methods used and the influence existing methodological problems can have on the interpretation of data. An awareness of these factors is important in establishing optimal dosage regimes to treat lower airway infections in horses.