Aminoglycosides are increasingly administered as a single large daily dose rather than divided doses. The pharmacodynamic basis for once-daily aminoglycoside dosing is:

• A They exhibit concentration-dependent killing plus a significant post-antibiotic effect ✓
• B Time above MIC is the parameter that best predicts their killing
• C Their half-life lengthens progressively as the single dose increases
• D Once-daily dosing eliminates the need for therapeutic drug monitoring

Explanation

Aminoglycosides show concentration-dependent bactericidal activity, meaning higher peak concentrations kill organisms faster and more completely. They also produce a post-antibiotic effect, continued suppression of bacterial growth after drug levels fall below the MIC. Together these allow a large once-daily dose that maximizes peak-to-MIC ratio while allowing a drug-free interval that reduces nephrotoxicity and ototoxicity. Time above MIC governs beta-lactams, not aminoglycosides, and monitoring is still required in renal impairment.

Reference: Katzung Basic and Clinical Pharmacology, 16th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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