Why use it

AUC-guided monitoring reduces nephrotoxicity while maintaining efficacy compared to trough-only strategies. Now the recommended approach per major guidelines.

About

AUC/MIC-guided vancomycin dosing calculator based on 2020 ASHP/IDSA/SIDP consensus guidelines. Replaces trough-only monitoring. Targets AUC24/MIC of 400-600 mg·h/L for MRSA infections (assuming MIC ≤1 mg/L).

When to use

Adults requiring vancomycin for serious infections (MRSA bacteremia, endocarditis, pneumonia, meningitis)
Patients at high risk of nephrotoxicity
AUC-based monitoring with two-level Bayesian or first-order PK estimation
Determining initial empiric dosing based on renal function

Formula

Empiric dose: 15-20 mg/kg q8-12h based on CrCl Loading dose (critically ill): 25-30 mg/kg × 1 Vd (L/kg) ≈ 0.7 (range 0.4-1.0) ke (hr⁻¹) = 0.00083 × CrCl + 0.0044 t½ = 0.693/ke AUC24 = Dose_total_24h / CrCl_adj (Bayesian preferred in practice)

Pearls & pitfalls

Target AUC24 400-600 mg·h/L; avoid AUC >600 to reduce nephrotoxicity.
Assumes S. aureus MIC ≤1 mg/L by broth microdilution — if MIC=2, alternative agents preferred.
Loading dose: 25-30 mg/kg for critically ill patients.
Dose on actual body weight (ABW); for obese patients use adjusted body weight.
CrCl by Cockcroft-Gault using actual body weight for dosing interval selection.
Adjust dose/interval every 2-3 days based on AUC monitoring.

Next steps

Target AUC24/MIC = 400-600 mg·h/L. For empiric dosing: 15-20 mg/kg IV q8-12h (based on CrCl). Obtain two levels (pre and post-distribution) for AUC calculation after 3rd or 4th dose.

Evidence

Rybak et al. ASHP/IDSA/SIDP 2020 Vancomycin Consensus Guidelines. Am J Health Syst Pharm. 2020;77(11):835-864.

References

Rybak MJ et al. Therapeutic monitoring of vancomycin for serious methicillin-resistant Staphylococcus aureus infections: a revised consensus guideline. Am J Health Syst Pharm. 2020;77(11):835-864. — link

Vancomycin AUC Dosing

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