Antimicrobial Use Guidelines (AMUG) version 21 - UW Health

To address 3-hour infusions of meropenem in renal dysfunction, Dr. Drusano (personalcommunication) ran a Monte Carlo simulation for estimated CrCl = 40 ml/min (500mg Q6H), 30ml/min (500mg Q8H) and 17 ml/min (500mg Q12H). The results are in the following table forpercent of patients with meropenem > MIC for 40% of the dosing interval.MIC (mg/L) Est CrCl = 40 ml/min Est CrCl = 30 ml/min Est CrCl = 17 ml/min2 99% 99% 96%4 92% 88% 75%Based on these results, the guidelines renal dosing protocol appears valid.CefepimeLee, et al. used a Monte Carlo simulation to evaluate pharmacodynamic principles of cefepimeusing various dosing regimens including intermittent infusions, prolonged infusions andcontinuous infusions. 5 By using the parameter 50% fT>MIC, for organisms with an MIC < 4mcg/ml, all regimens evaluated achieved this target goal. If the MIC is increased to 16 mcg/ml,2g every 6-8 hours given by 30 minute infusions, 2g every 6-8 hours given by 3-4 hour infusionsand 4-6g/day given by continuous infusion achieved the target goal. Due to the lack of datashowing benefit with prolonged infusions, cefepime will continue to be dosed as a thirty minuteinfusion.B. ObjectiveProlonged infusions of piperacillin/tazobactam and meropenem will be used at UWHC in patientswith appropriate parenteral access to maximize pharmacodynamic principles and potentiallydecrease mortality, length of stay, and antimicrobial resistance.C. GuidelineAll patients prescribed meropenem or piperacillin/tazobactam will automatically be dosed withprolonged infusions (3 or 4 hours) after the first dose. The first dose will be infused over theconventional 30 minutes to obtain therapeutic levels quickly and potentially decrease mortality. 6Adult cystic fibrosis patients may receive prolonged infusions for pipercillin/tazobactam andmeropenem at the discretion of the Advanced Pulmonary service, but are not limited to dosesspecified in this guideline.. Patients receiving continuous renal replacement therapy will beexcluded from prolonged infusions and will be given the CRRT dose. Patients with CNSinfections will also be excluded from the trial since these patients usually will need higher dosesof the prescribed antibiotic. Finally, neutropenic patients will receive prolonged infusion, but willnot be eligible for meropenem dose reduction and will continue to receive high-dose prolongedinfusion meropenem.If a prescriber writes for a different dosing regimen, the pharmacist will automatically change tothe prolonged infusion regimen. The prescriber may write ‘Do not change to prolonged infusion’.The pharmacist and nurse should make all efforts to continue to use prolonged infusion; however,if intravenous access becomes problematic, the pharmacist will change to the renally-dosed 30minute infusion.