Pharmacokinetics and the dosage regimen of antimicrobial agents

Some consider antimicrobial therapy an art rather than a science. The drug concentration at the site of infection is often assumed to be a major factor in predicting efficacy and high serum concentrations are assumed to have an advantage by increasing the amount of drug that diffuses into the various body tissues and fluids. Pharmacokinetic studies, along with pharmacodynamic studies, remain to be an important and essential portion of the data base needed for the determination of a proper dosage regimen for antimicrobial agents prior to clinical trials. Additional studies are needed to define the influence of the post antibiotic effect and post antibiotic leukocyte enhancement, as well as the subminimal and supraminimal inhibitory concentrations, on establishing the proper dosage regimen. It is recommended that the insert for a prescription antimicrobial agent should contain pharmacokinetic parameters, such as volume of distribution, t1/2 and body clearances.