Vancomycin Reactions

Red man syndrome
  • Common
  • Anaphylactoid reaction usually related to rate of infusion (can occur with first ever dose)
  • Flushing, erythema, pruritus, usually of the upper body, neck, face > lower body. Muscle spasms in the back and chest, dyspnea, and hypotension may also occur.
Immediate hypersensitivity
(Type I)
Other reactions
  • Vancomycin-related linear IgA bullous dermatosis (LABD)
  • SJS, TEN
  • Leukocytoclastic vasculitis

Infusion Rate

Slow - lower risk for red man syndrome-----
Fast- higher risk for red man syndrome----
  • Rate ≤10 mg/min
  • Dose over ≥100 min
  • 1 gram over ≥1 hour
  • Rate >10 mg/min
  • 1 gram over <1 hour


  • Clinical diagnosis
  • Tryptase and/or histamine levels after the reaction occurs are not able to distinguish between red man syndrome and IgE-mediated allergy
  • Skin testing
    • Not standardized
    • Reported that a positive ID skin test at 0.1-1 mcg/mL or lower is strongly suggestive of IgE-mediated allergy, while irritant reactions occurred at concentrations ≥10 mcg/mL in controls

Management (Weller)

Prevention of red man syndrome

  • Mast_cell_degranulators.pngInfuse over ≥100 min or at a rate ≤10 mg/min, whichever results in a slower infusion
    • If faster infusion (>10 mg/min or 1 gram over 1 hour) required, consider empiric premedication with oral H1 and H2 blocker (e.g. diphenhydramine 50 mg PO and ranitidine 150 mg PO) 1 hour before infusion
  • Avoid coadministration of medications that may predispose to mast cell degranulation

Treatment of red man syndrome

  • Mild - flushing/pruritus that is not bothersome to patient
    • Stop infusion, when symptoms subside (usually minutes), resume infusion at 1/2 the rate
  • Moderate - flushing/pruritus withoutchest pain, muscle spasms, or hypotension
    • Stop infusion, give H1 blocker (e.g. diphenhydramine 50 mg PO or IV); when symptoms subside, resume infusion at 1/2 the rate
    • For future doses use premedication, consider role of patient's other medications (see table), infuse over at least 4 hours
  • Severe - pains/spasms or hypotension present
    • Stop infusion, give H1 and H2 blockers (e.g. diphenhydramine 50 mg IV and ranitidine 50 mg IV), IV fluid if needed
    • For future doses use premedication, consider role of patient's other medications (see table),
      infuse over at least 4 hours

  • Recurrent red man syndrome despite premedication and slow infusion rate
    • Consider alternative antibiotics, many patients labeled as PCN-allergic can receive PCN after an allergist's evaluation
    • Consider desensitization

Treatment of IgE-mediated reactions