From the Guidelines
Vancomycin should be used to treat pneumonia when there is confirmed or strongly suspected Methicillin-resistant Staphylococcus aureus (MRSA) infection, with a typical dosing regimen of 15-20 mg/kg (based on actual body weight) intravenously every 8-12 hours, and a target trough concentration of 15-20 μg/mL for serious infections like pneumonia, as recommended by the Infectious Diseases Society of America 1. The use of vancomycin is specifically indicated when empiric coverage for MRSA is needed in patients with risk factors such as recent hospitalization, prior MRSA infection, residence in long-term care facilities, recent antibiotic use, or in areas with high MRSA prevalence. Some key points to consider when using vancomycin for pneumonia include:
- Obtaining appropriate cultures before starting therapy when possible, and de-escalating to a more targeted antibiotic if cultures reveal a susceptible organism
- Monitoring vancomycin trough concentrations to ensure adequate levels and minimize the risk of nephrotoxicity
- Adjusting doses based on creatinine clearance in patients with renal impairment
- Considering alternative agents, such as linezolid, in patients with renal insufficiency or those receiving other nephrotoxic agents, as suggested by studies 1
- Maintaining adequate hydration and monitoring renal function regularly during treatment. It's also important to note that vancomycin has a narrow therapeutic window and requires therapeutic drug monitoring, and that high failure rates have been observed in the treatment of MRSA pneumonia, particularly ventilator-associated pneumonia (VAP), which has been attributed to vancomycin’s poor penetration into pulmonary tissue and lung epithelial lining fluid 1.
From the Research
Vancomycin Use in Pneumonia
- Vancomycin is recommended as the treatment of choice for methicillin-resistant Staphylococcus aureus (MRSA) pneumonia, with a desired trough concentration of 15 to 20 mg/L 2.
- A vancomycin regimen of 1 g i.v. every 12 hours in critically ill trauma patients with MRSA pneumonia and normal renal function is unlikely to achieve trough concentrations of 15 to 20 mg/L, and doses of at least 1 g i.v. every 8 hours are needed 2.
- The British Thoracic Society, American Thoracic Society, and Infectious Diseases Society of America guidelines recommend vancomycin for MRSA pneumonia, based on evidence suggesting that a vancomycin AUC₀₋₂₄/MIC ratio of 400 predicts clinical success against MRSA pneumonia 3.
Dosage Recommendations
- New recommendations for vancomycin dosages and dosing intervals for MRSA-infected pneumonia patients with various degrees of renal function impairment have been established, with recommended doses and intervals based on individual creatinine clearance (CLcr) 4.
- For patients with CLcr of 80-100 ml/min, a dose of 20 mg/kg every 12 h is recommended, while for patients with CLcr of 30 ml/min, a dose of 18 mg/kg every 48 h is recommended 4.
Treatment Outcomes
- Vancomycin has been the treatment of choice for nosocomial MRSA pneumonia, but linezolid has demonstrated similar efficacy to vancomycin in randomized clinical trials, and may be superior in some cases 5.
- Predictors of vancomycin failure in MRSA bacteraemia include endocarditis and pneumonia, and vancomycin provides suboptimal therapy in these situations 6.
- High failure rates have been observed in patients with MRSA bacteraemia treated with vancomycin, despite high vancomycin troughs and low rates of nephrotoxicity 6.