What is the right gentamicin dose for multiple trauma patients? A Monte Carlo simulation exploration study

The appropriate dose of gentamicin is important to prevent and treat infections. The study aimed to determine the optimal dose of gentamicin to achieve the probability of pharmacokinetic/pharmacodynamic (PK) targets for efficacy and safety in multiple trauma patients.

PK parameters of gentamicin in multiple trauma patients were gathered to develop a one-compartment PK model for prediction. The Monte Carlo simulation method was performed. The 24-h area under the concentration time curve to the minimum inhibitory concentration ratio (AUC24h/MIC) ≥50 was defined for the infection prevention target. AUC24h/MIC ≥110 or the maximum serum concentration to MIC ratio ≥8-10 was for the treatment of serious Gram-negative infection target. The risk of nephrotoxicity was the minimum serum concentration ≥2 mg/L. The optimal dose of gentamicin was determined when the efficacy target was >90% and the risk of nephrotoxicity was lowest.

The optimal gentamicin dose to prevent infection when the MIC was <1 mg/L was 6-7 mg/kg/day. A higher dose of gentamicin up to 10 mg/kg/day could not reach the target for treating serious Gram-negative infection when the expected MIC was ≥1 mg/L. The probability of nephrotoxicity was minimal at 0.2-4% with gentamicin doses of 5-10 mg/kg/day for 3 days.

Once daily gentamicin doses of 6-7 mg/kg are recommended to prevent infections in patients with multiple trauma. Gentamicin monotherapy could not be recommended for serious infections. Further clinical studies are required to confirm our results.