Aminoglycosides exhibit concentration-dependent bactericidal activity and a prolonged post-antibiotic effect (PAE). The clinical implication of these PK/PD properties is:
- A They should be given as a single large daily dose to maximize Cmax/MIC ratio and exploit the PAE, while reducing nephrotoxicity by allowing trough recovery periods ✓
- B They should be given in multiple small doses to maintain MIC throughout the day
- C Continuous infusion over 24 hours achieves optimal bactericidal activity
- D Dose should be based on time above MIC target of 40–50%
Explanation
Aminoglycosides are concentration-dependent antibiotics where bactericidal efficacy correlates with the peak (Cmax)/MIC ratio. Higher peak concentrations achieved with once-daily dosing (ODD) increase bactericidal effect and exploit the prolonged post-antibiotic effect (PAE), during which bacterial regrowth is suppressed even below MIC. Additionally, the nephrotoxic aminoglycoside transport into renal proximal tubular cells is saturable — once-daily dosing allows trough levels to fall, permitting tubular cell recovery and significantly reducing nephrotoxicity compared to multiple daily dosing.
Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.