Vancomycin


Preferred antimicrobial agent for the treatment of methicilline-resistant Staphylococcus aureus. Vancomycin is a complex tricyclic glycopeptide obtained from the nocardia species Amycolatopsis orientalis.
 
Incidence
Adults: 5 to 14%.
 
Children: 1.6 to 35%.
 
Risk factors
Association with narcotics.
 
Age < 40 years: risk factor for infusion-related and delayed reactions.
 
Duration > 7 days: risk factor for delayed reactions.
 
Clinical manifestations
"Red man syndrome": flushing, pruritus, hypotension (occurs in 50% to 90% of normal volunteers infused with 1 g of vancomycin over one hour).
 
Delayed cutaneous eruptions: maculopapular rashes, exfoliative dermatitis, erythema multiforme, Stevens-Johnson’s syndrome, toxic epidermal necrolysis. Occurring 8 to 55 days after the start of treatment. Often associated with eosinophilia, fever, interstitial nephritis.
 
Linear IgA bullous dermatosis.
 
One case with dyspnea, fever, hypoxia and eosinophilia (inhaled vancomycin used in decontamination of the respiratory tract for allogenic bone marrow transplantation).
 
Diagnostic methods
Cutaneous testing.
 
Skin-prick tests are usually negative.
 
Intradermal skin-tests: few cases published positive with 0.02 ml at 0.1 µg/ml.
 
Basophil histamine release test.
 
One case published of specific histamine release and cross-reactivity between vancomycin and teicoplanin.
 
Mechanisms
"Red man syndrome" is due to histamine release into the blood by vancomycin with no antibody or complement involvement. Hypotension is linked to peripheral vasodilatation following histamine release. Myocardial dysfunction is secondary to endogenous myocardial histamine release, or direct inotropic myocardial depression.
 
IgE-mediated hypersensitivity reactions do exist in a few cases.
 
Management
Prevention of the "red man syndrome":
 
Decreasing vancomycin doses.
 
Slowing infusion rate (no faster than 10 mg/ min).
 
Pretreatment with an antihistamine (hydroxyzine 50 mg 2 hours before a vancomycin dose).
 
Desensitization
 
Rush: 0.5 mg/500 ml//4 hours to 1 000 mg/250 ml//4 hours in 13 days.
 
Fast: 0.0001 mg/ml infusion to 10 mg/ ml infusion in 100 minutes with pretreatment (antihistamines).
 
Cross-reactivity between vancomycin and teicoplanin remains controversial.

References

  1. Marik P.E, Ferris N, "Delayed hypersensitivity reaction to vancomycin", Pharmacotherapy., 1997 ; 17 (6): 1341-44
  2. Korman P.M, Turnidge J.D, Grayson M.L, "Risk factors for adverse cutaneous reactions associated with intravenous vancomycin", J. Antimicrob. Chemother., 1997 ; 39 (3): 371-81
  3. Anne S, Middleton E Jr, Reisman R.E, "Vancomycin anaphylaxis and successful desensitization", Ann. Allergy., 1994 ; 73 (5): 402-4
  4. Wong J.T, Ripple R.E, Mc Lean J.A, Marks D.R, Bloch K.J, "vancomycin hypersensitivity: synergism with narcotics and "desensitization" by a rapid continuous intravenous protocol", J. Allergy. Clin. Immunol., 1994 ; 94 (2.1): 189-94

As in all diagnostic testing, the diagnosis is made by the physican based on both test results and the patient history.