From our very own ED pharmacist, Natalija Farrell:
- Methicillin-resistant Staphylococcus aureus (MRSA) infections and MRSA-related hospitalizations continue to increase.1
- Vancomycin remains the cornerstone for the treatment of suspected or confirmed MRSA infections.
- Its efficacy is measured by troughs (goal 10-20 mg/L) and troughs <10 mg/L foster vancomycin resistance.2
- Due to the increased mortality in patients with vancomycin susceptible aureus with higher minimum inhibitory concentrations (“MIC creep”) and emergence of vancomycin intermediate or resistant S. aureus (VISA, VRSA),3-5 it is even more paramount to dose vancomycin correctly and target troughs 15-20 mg/L.
- Emergency Departments are underdosing vancomycin in >70% of patients (especially in obese patients).
- Most patients received vancomycin 1 g IV. 6-7
- Traditional Dosing: Vancomycin 15 – 20 mg/kg IV
- Loading Doses: Vancomycin 25 – 30 mg/kg IV x1
- Should be used to in critically ill patients (e.g. sepsis, febrile neutropenia, meningitis, endocarditis, etc.)
- More rapidly achieve therapeutic levels
- Minimizes vancomycin resistance
- Not associated with increased adverse effects
- Renal function determines the frequency not the dose
- Totally daily doses >4 g increase the risk of nephrotoxicity
|Weight*||Traditional Vancomycin IV Dosing†||Vancomycin IV Loading Dose†|
|50 kg||750 mg, 1 g||1.25 g, 1.5 g|
|60 kg||1 g, 1.25 g||1.5 g, 1.75 g|
|70 kg||1 g, 1.25 g, 1.5 g||1.75 g, 2 g|
|80 kg||1.25 g, 1.5 g||2 g|
|90 kg||1.5 g, 1.75 g||2 g|
|100 kg||1.5 g, 1.75 g, 2 g||2 g|
|110 kg||1.75 g, 2 g||2 g|
|>110 kg||2 g||2 g|
|*Actual body weight
†Dose rounded to the nearest 250 mg to a maximum of 2 g
- Proper vancomycin dosing will help curb the increasing incidence VISA and VRSA
- Vancomycin 1 g IV is not appropriate for all patients.
- Critically ill patients should receive vancomycin loading doses (e.g. 50 kg = 1.5 g, 60 kg = 1.75 g; ≥70 kg = 2 g)
- Mera RM, Suaya JA, Amrine-Madsen H, et al. Increasing role of Staphylococcus aureus and community-acquired methicillin-resistant Staphylococcus aureus infections in the United States: a 10-year trend of replacement and expansion. Microb Drug Resist 2011;17(2):321-8.
- Rybak MJ, et al. Therapeutic monitoring of vancomycin in adult patients: a consensus review of the American Society of Health-System Pharmacists, the Infectious Diseases Society of America, and the Society of Infectious Diseases Pharmacists.Am J Health Syst Pharm 2009;66(1):82-98.
- van Hal SJ, et al. The clinical significance of vancomycin minimum inhibitory concentration in Staphylococcus aureus infections: a systematic review and meta-analysis.Clin Infect Dis2012;54(6):755-71
- Lodise TP, et al. Relationship between vancomycin MIC and failure among patients with methicillin-resistant Staphylococcus aureus bacteremia treated with vancomycin.Antimicrob Agents Chemother 2008;52(9):3315-20.
- Appelbaum PC. The emergence of vancomycin-intermediate and vancomycin-resistant Staphylococcus aureus. Clin Microbiol Infect 2006;12(S1):16-23.
- Rosini JM, et al. Prescribing habits of vancomycin in the emergency department: are we dosing appropriately?J Emerg Med 2013;44(5):979-84
- Fuller BM, et al. Emergency department vancomycin use: dosing practices and associated outcomes.J Emerg Med 2013;44(5):910-8.
- Reardon J, Lau TTY, and Ensom MHH. Vancomycin loading doses: a systematic review. Ann Pharmacother 2015;49(5):557-65.
- Rosini JM, Laughner J, Levine BJ, Papas MA, Reinhardt JF, and Jasani NB. A randomized trial of loading vancomycin in the emergency department. Ann Pharmacother 2015;49(1):6-13.
- Lodise TP, Lomaestro B, Graves J, Drusano GL. Larger vancomycin doses (at least four grams per day) are associated with an increased incidence of nephrotoxicity. Antimicrob Agents Chemother 2008;52:1330-6.