Hayes – Vanc & Zosyn is NOT the Answer to Everything

This week, Dr. Bryan Hayes – Clinical Pharmacologist and expert in Toxicology gives an amazing talk highlighting 10 of his top tips for antimicrobial use in the emergency department & for the critically ill patient.  This is probably one of the most clinically useful lectures I’ve listened to in a long time.  Bryan has actually started his own campaign to make sure we are all using Vanc right in 2014 – he even made it a New Years Resolution of his own (Check out his post on Academic Life in EM)


  • How to correctly give a dose of vancomycin
    • Dose: 15-20 mg/kg every 8-12 hours in patients with normal renal function, MAX: 2 grams
    • Consider an even higher loading dose In seriously ill patients (e.g. sepsis, meningitis, infective endocarditis) with suspected MRSA infection: 25-30 mg/kg again, MAX 2 grams (ISDA recommendation).
    • Weight based dosing by using actual body weight
    • In adults, we round to the nearest 250 mg increment (to help out your friendly pharmacist)
  • In the critically ill obese patient, aminoglycosides should be dosed by adjusted body-weight
    • ABW = Ideal BW + 0.4*(Actual BW – Ideal BW)
  • A Penicillin allergy is NOT a contraindication to cephalosporin use!
    • 3rd, 4th, & 5th Generation cephalosporins can be safely given to PCN allergic patients.
    • Avoid keflex, cefaclor, cefadroxil, cefprozil as their beta lactam side chain is similar to PCN.
    • Carbapenems are also safe in PCN allergic patients
  • HCAP “double coverage” should include only 1 beta-lactam antimicrobial, the 2nd agent should have a different mechanism of action (i.e. fluoroquinolone, etc.)
  • Don’t forget the atypical coverage in HCAP patients!  Send the urine legionella antigen.
  • CAP patients admitted to the ICU should not be treated with a fluoroquinolone alone.  Add the beta-lactam.

Thanks Bryan – we’ll make sure to get it right in 2014.


  1. Ryback M, 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 Pharm2009;66(1):82-98.
  2. Rosini JM, et al. Prescribing habits of vancomycin in the emergency department: are we dosing appropriately? J Emerg Med 2013;44(5):979-84.
  3. Liu C, et al. Clinical practice guidelines by the Infectious Diseases Society of America for the treatment of methicillin-resistant Staphylococcus aureus infections in adults and children.Clin Infect Dis 2011;52(3):e18-55.
  4. Fuller BM, et al. Emergency department vancomycin use: dosing practices and associated outcomes. J Emerg Med 2013;44(5):910-8.
  5. Frankel KC, et al. Computerized provider order entry improves compliance of vancomycin dosing guidelines in the emergency department. Am J Emerg Med 2013;31(12):1715-6.
  6. Campagna JD, Bond MC, Schabelman E, Hayes BD. The use of cephalosporins in penicillin-allergic patients: a literature review. J Emerg Med. 2012;42(5):612-20.

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  1. Pingback: Do it Right – Vancomycin Dosing | neurocritical.de

  2. Jenny Maccagnano

    For pts with acute or chronic renal failure, how do you suggest dosing vanc if the pt is not a dialysis pt. As I have had pharmacy call me when I weight based the dose, when the pt had an elevated creatinine.

    For pts in septic shock or those needing broad spectrum coverage, we often use vanc and zosyn. What do you recommend in place of zosyn?

    1. Bryan Hayes

      Jenny, these are great questions. There isn’t a lot of clear guidance for patients with renal dysfunction. However, if the patient is still making urine, the first dose should generally be weight based. We usually adjust the interval for renal impairment cases (eg, q24 hours instead of q12 hours). For dialysis patients, 1 gm is a good default dose as many end up on a schedule of 1 gm after each dialysis session.

      Zosyn is certainly an appropriate antibiotic in some circumstances. Septic shock and intra-abdominal infections are two examples. It’s important to see what your institution’s antibiogram has for zosyn susceptibility patterns. For pseudomonas at my hospital, zosyn is 78% while cefepime is 90%. If I’m worried about pseudomonas and I have no old cultures to help guide therapy, I’m choosing cefepime every time and will add anaerobic coverage with metronidazole if needed.

  3. chase donaldson

    What studies showed worse outcomes with vancomycin for MSSA? Could you post those references?

    Similarly, could you show the references for your comment regarding complicated UTI being better treated inpatient with a fluoroquinolone versus a beta lactam for inpatient treatment?

    1. John Greenwood

      Hi Chase,

      Spoke with Bryan, and he asked me to pass along these references:
      1. Kim SH, Kim KH, Kim HB, et al. Outcome of vancomycin treatment in patients with methicillin-susceptible Staphylococcus aureus bacteremia. Antimicrob Agents Chemother. 2008;52(1):192-7. [Pubmed]
      2. Stryjewski ME, Szczech LA, Benjamin DK, et al. Use of vancomycin or first-generation cephalosporins for the treatment of hemodialysis-dependent patients with methicillin-susceptible Staphylococcus aureus bacteremia. Clin Infect Dis. 2007;44(2):190-6. [Pubmed]
      3. Schweizer ML, Furuno JP, Harris AD, et al. Comparative effectiveness of nafcillin or cefazolin versus vancomycin in methicillin-susceptible Staphylococcus aureus bacteremia. BMC Infect Dis. 2011;11:279. [Pubmed]

      Also, as far as the 2nd part of your question, here is his response:
      The guidelines (With respect to pyelonephritis) make comments such as “the beta-lactams generally have inferior efficacy and more adverse effects, compared with other UTI antimicrobials” and “oral beta-lactam agents are less effective than other available agents for treatment of pyelonephritis.” There is microbiologic data that shows beta-lactams don’t completely eradicate urinary bacteria as well as FQs or Bactrim. That is why we tend to use longer courses. If an individual hospital antibiogram is favorable toward use of FQs or Bactrim for these cases, then they should be used over beta-lactams. At our institution, that is not the case, so we tend to use more beta-lactams.

      Hope that helps.

      — John

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