Briefly outline the dosing adjustment and the monitoring necessary for each of the following drug groups in patients with established septic shock and moderate to severe renal dysfunction (without dialysis):

  1. Aminoglycosides
  2. Fluoroquinolones
  3. Beta-Lactams
  4. Carbapenems
  5. Glycopeptides

[Click here to toggle visibility of the answers]

College Answer

  • Aminoglycosides
    • High initial dose and monitor trough concentrations. Extend interval. May be necessary to decrease dose and monitor with MIC data
  • Fluoroqinolones
    • Reduce frequency but maintain dose.
    • Monitor QT interval
  • Beta Lactams
    • Can reduce dose OR frequency
    • Monitoring unnecessary
  • Carbapenems
    • As for Beta Lactams
  • Glycopeptides
    • High dosing on day one dose adjustments according to Cmin and dependent on degree of renal dysfunction

Discussion

Another question which relies on memory rather than on the capacity to reason. However, the classes of antibiotics discussed here are common ones, and one should be intuitively familiar with their use.

In a brief summary:

  • Beta-lactams can be either dose-adjusted or interval-adjusted
  • Carbapenems can be either dose-adjusted or interval-adjusted
  • Aminoglycosides keep the same dose, and are interval-adjusted (with monitoring of drug levels)
  • Fluoroquinolones keep the same dose, and are interval-adjusted (with monitoring of the QT interval)
  • Glycopeptides keep the same dose, and are interval-adjusted (with monitoring of drug levels)

References

McKenzie, Cathrine. "Antibiotic dosing in critical illness." Journal of antimicrobial chemotherapy 66.suppl 2 (2011): ii25-ii31.

Ulldemolins, Marta, et al. "Antibiotic dosing in multiple organ dysfunction syndrome." CHEST Journal 139.5 (2011): 1210-1220.

Lipman, J. "Towards better ICU antibiotic dosing." Critical Care and Resuscitation 2000; 2: 282-289 .

Trotman, Robin L., et al. "Antibiotic dosing in critically ill adult patients receiving continuous renal replacement therapy." Clinical infectious diseases 41.8 (2005): 1159-1166.