Vancomycin 50-mg/kg dosage helps achieve target AUCf24h

An empirical dosage of approximately 50 mg/kg on the first day of vancomycin therapy is needed to achieve an area under the concentration-time curve (AUC) in the first 24 h (AUCf24h), suggests a study while noting the use of two-point sampling in Bayesian estimations to improve accuracy.

This multicentric prospective study was carried out across five hospitals, including 27 critically ill patients and 395 samplings performed on the first day or days 3‒5 of therapy.

The investigators assessed the cumulative dose on the first day for the trapezoidal AUCf24h >400 μg·h/mL and the predictive performances of AUC and clearance in limited sampling. They also evaluated the probability of adherence to AUCf24h within 400‒600 μg·h/mL in the guidelines-compliant or noncompliant doses.

The mean cumulative dose on the first day was higher in the group with AUCf24h >400 μg·h/mL than in the group with AUCf24h <400 μg·h/mL (49.3 vs 42.1 mg/kg; p=0.01) for patients with creatinine clearance >90 mL/min, respectively.

Notably, the use of two-point concentrations at trough and peak improved the biases and variations of Bayesian posterior AUC by using only a trough concentration.

In addition, adherence to AUCf24h was significantly more probable in the guidelines-compliant than the noncompliant group (66.7 percent vs 11.1 percent; p<0.01).

“AUC-guided dosing is recommended in vancomycin therapy,” the investigators said.