Vancomycin Dosing for Severe Pneumonia

Initial Dosing Strategy

For seriously ill patients with severe pneumonia, a loading dose of 25-30 mg/kg (actual body weight) is recommended to rapidly achieve therapeutic concentrations 1, 2
Given the risk of red man syndrome with large doses, consider prolonging the infusion time to 2 hours and using an antihistamine prior to administration of the loading dose 1
Standard maintenance dosing of 15-20 mg/kg (actual body weight) every 8-12 hours should be initiated after the loading dose 1, 2

Trough vancomycin concentrations should be obtained at steady state conditions, prior to the fourth or fifth dose 1, 2
For severe pneumonia, target trough concentrations of 15-20 μg/mL are recommended to achieve an AUC/MIC ratio >400, which correlates with clinical efficacy 1, 2
Monitoring is strongly recommended for patients who are morbidly obese, have renal dysfunction, or have fluctuating volumes of distribution 1

Weight-based dosing is particularly important in obese patients, who are likely to be underdosed when conventional dosing strategies of 1 g every 12 hours are used 1, 2

Underdosing vancomycin can lead to treatment failure and promote resistance development 1, 2
For isolates with a vancomycin MIC >2 μg/mL, an alternative to vancomycin should be considered as target AUC/MIC ratios may not be achievable with conventional dosing 1, 2
Vancomycin-induced nephrotoxicity risk increases with trough levels >15 mg/mL, especially when combined with other nephrotoxic agents 1

If the patient has not had a clinical or microbiologic response to vancomycin despite adequate debridement and removal of other foci of infection, an alternative to vancomycin is recommended regardless of MIC 3
High-dose daptomycin (10 mg/kg/day), linezolid (600 mg PO/IV twice daily), or TMP-SMX (5 mg/kg IV twice daily) may be considered as alternatives 3