Pharmacokinetic and Pharmacodynamic Properties of Meropenem

Pharmacokinetic and pharmacodynamic profiles of antibiotics are important in determining effective dosing regimens. Although minimum inhibitory concentration (MIC) data reflect microbial susceptibility to an antibiotic, they do not provide dosing information. The integration of pharmacokinetic and microbiological data, however, can be used to design rational dosing strategies. Meropenem is a broad-spectrum β-lactam antibiotic that penetrates most body fluids and tissues rapidly after intravenous administration. Meropenem undergoes primarily renal elimination; therefore, dosage adjustment is required for patients with renal impairment. Meropenem is indicated for the treatment of complicated skin and skin-structure infections, complicated intra-abdominal infections, and bacterial meningitis. Meropenem has time-dependent bactericidal activity; thus, the percentage of time that free-drug concentrations are higher than the MIC (%T>MIC) best characterizes the drug's pharmacodynamic profile (bactericidal target of ∼40%T>MIC). Pharmacodynamic modeling can identify regimens with the greatest probability of attaining this target, and probabilities can be compared with clinical and microbiological responses in patients.