Comparative AKI Incidence in Obese Patients: AUC vs Trough Vancomycin Dosing

Overview

This retrospective cohort study compared acute kidney injury (AKI) incidence in obese patients receiving vancomycin dosed by area under the concentration–time curve (AUC) versus trough-based strategies. The AUC dosing group demonstrated significantly lower AKI rates and higher initial target attainment than the trough group.

Background

Vancomycin is a first-line treatment for severe methicillin-resistant Staphylococcus aureus (MRSA) infections, with dosing monitoring shifting from trough-based to AUC-guided strategies to reduce nephrotoxicity. Obese patients present unique pharmacokinetic challenges, including altered clearance and volume of distribution, which complicate dosing. Limited data exist on the safety and efficacy of AUC-based dosing in this population, despite rising obesity prevalence. This study evaluates AKI incidence and target attainment after transitioning from trough to AUC dosing in obese patients.

Data Highlights

Key Findings

• AKI rates were significantly lower in the AUC dosing group (11.3%) compared to the trough group (25.2%).
• AUC-based dosing achieved higher initial target attainment (50.0%) versus trough dosing (23.9%).
• After adjustment, AUC dosing was associated with reduced AKI risk for cumulative vancomycin doses below the median of 10,250 mg (OR 0.47, 95% CI 0.25–0.88).
• No significant AKI risk reduction was observed with AUC dosing at doses above the median cumulative dose.
• Pharmacokinetic differences in obese patients necessitate tailored dosing strategies; AUC dosing better accounts for these variations.

Clinical Implications

Clinicians treating obese patients with severe MRSA infections should consider AUC-guided vancomycin dosing to reduce AKI risk and improve target attainment. Careful dose adjustment is critical, especially for cumulative doses below 10,250 mg, to maximize safety benefits. Transitioning to AUC monitoring protocols may enhance therapeutic outcomes in this high-risk population.

Conclusion

In obese patients receiving vancomycin for severe MRSA infections, AUC-based dosing significantly reduces AKI incidence and improves target attainment compared to trough-based dosing. These findings support adopting AUC-guided monitoring to optimize vancomycin therapy in obesity.

References

1. Crass et al 2022 -- AUC-Based Vancomycin Dosing in Obese Patients
2. Vancomycin Consensus Guidelines 2020 -- Therapeutic Monitoring Recommendations
3. Institutional Retrospective Cohort Study 2014-2022 -- AKI Incidence with Vancomycin Dosing Strategies