PHARMACOLOGY AND CLINICAL RELEVANCE OF MACROLIDE ANTIMICROBIALS

摘要

Bovine respiratory disease is the most common cause of morbidity and mortality in beef cattle. The bacterial pathogens most frequently recovered from cattle with respiratory disease include Mannheimia haemolytica, Pasteurella multocida, Histophilus somni, and Mycoplasma bovis. Administration of an effective antimicrobial agent is one of the most effective methods of preventing respiratory disease and the only effective method of treatment.The plasma pharmacokinetics of most of these antimicrobial agents have been studied extensively in cattle. Optimal dosing of antimicrobial agents is dependent not only on the pharmacokinetics, but also on the pharmacodynamics of the drug. Pharmacodynamicproperties of an antimicrobial drug address the relationship between drug concentration and antimicrobial activity. Pharmacokinetic-pharmacodynamic studies play an important role in drug development and drug evaluation. At the moment, the most widely used pharmacokinetic-pharmacodynamic approaches for antimicrobial agents rely on plasma concentrations as the pharmacokinetic input and minimum inhibitory concentration (MIC) as the pharmacodynamic input value. For many drugs, microorganisms, and disease processes, measurement of plasma concentration is an adequate surrogate marker of efficacy. However, for some drugs and disease states, concentration at the site of infection is more relevant and directly related to the desired therapeutic effect. This presentation reviews current information regarding pulmonary disposition of antimicrobial agents on bovine respiratory disease.