Extended-interval (once-daily) aminoglycoside dosing produces efficacy comparable to conventional multiple-dose regimens while reducing toxicity. This strategy is rational because aminoglycosides exhibit:

• A Time-dependent killing with a minimal post-antibiotic effect
• B Concentration-dependent killing with a significant post-antibiotic effect ✓
• C Purely bacteriostatic activity independent of peak levels
• D Activity determined solely by time above MIC regardless of peak concentration

Explanation

Aminoglycosides show concentration-dependent bactericidal activity, so higher peaks give greater kill rates, and they have a clinically significant post-antibiotic effect, meaning bacterial growth remains suppressed after serum levels fall below the MIC. Together these allow one large daily dose with equal efficacy and lower accumulation-related nephrotoxicity. Time-dependent drugs such as beta-lactams require frequent dosing instead, which is exactly why their PK/PD driver differs.

Reference: Katzung Basic and Clinical Pharmacology, 15th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.