Which statement best describes trough level monitoring for vancomycin?

• A. To measure peak concentration
• B. To evaluate hydration status
• C. To adjust dosing based on liver function
• D. To balance efficacy and toxicity by ensuring trough levels within a target range

Answer: (D)

The main idea is that trough level monitoring for vancomycin is about keeping drug exposure within a safe and effective range. Trough is the lowest concentration in the bloodstream right before the next dose, and aiming for a target trough helps ensure the drug stays high enough to treat the infection but not so high that it damages the kidneys or other organs. Vancomycin dosing is adjusted to maintain that trough within the established range, reflecting a balance between efficacy (enough drug to kill bacteria) and toxicity (avoiding nephrotoxicity and other adverse effects). Peak measurements aren’t the focus for routine vancomycin dosing, and hydration status or liver function aren’t the primary reasons for trough monitoring.