How are aminoglycosides dosed and what monitoring is essential?

• A. Dosed by weight with peak and trough monitoring; monitor renal function and drug levels
• B. Fixed dosing daily without monitoring
• C. Dosed by age; monitor liver enzymes
• D. Continuous infusion with no monitoring

Answer: (A)

Aminoglycosides require careful balancing because they work best when concentrations are high enough to kill bacteria but are risky if too high for the kidneys and ears. Because of their narrow therapeutic index, dosing is based on body weight and then adjusted using therapeutic drug monitoring. Measuring peak and trough levels tells you whether the patient is getting an effective exposure without reaching toxic levels. Peaks are checked after a dose is given to ensure the drug reaches a sufficient concentration, while troughs are checked just before the next dose to ensure levels stay low enough to minimize toxicity. Renal function is monitored because kidney injury is a major risk with these drugs, and impaired clearance can cause accumulation even with correct dosing. In practice, dose and interval are tailored to the individual using weight-based calculations and renal function, with peak and trough levels guiding adjustments. Continuous infusion or no monitoring would still require drug level checks and renal assessment, and dosing by age or only monitoring liver enzymes does not fit the known safety and efficacy pattern of aminoglycosides.