Published Online: February 18, 2013
Every physician is likely to face a patient with a history of penicillin allergy for which a beta-lactam antibiotic is the preferred antibiotic regimen. Although the safest approach would be to avoid any beta-lactam in all patients with presumed penicillin allergy, this practice is not optimal as most patients with a history of penicillin allergy are not allergic, and commonly used alternative antibiotics carry additional costs, promote antimicrobial resistance, and can be less effective or more toxic. Therefore, guidelines on drug allergy provide management algorithms to allow safe administration of beta-lactam antibiotics to patients with a history of penicillin allergy. However, it is unclear if non-allergists adhere to these guidelines, particularly in the absence of allergists among the hospital staff.
In a recent issue of the The Journal of Allergy and Clinical Immunology: In Practice, Picard et al. studied in detail the management of patients with a history of penicillin allergy in a large Canadian tertiary-care academic hospital without allergists on staff. They reviewed the files of patients with a record of penicillin allergy admitted to the intensive care unit, coronary care unit, and on internal medicine wards over a one-year period. Documentation of the allergic status, need for antibiotics during hospitalization, and decision-making process underlying the choice of antibiotics was assessed for each patient. The costs associated with the use of alternative antibiotics instead of the preferred beta-lactam antibiotic were calculated. A survey was also conducted among the physicians on staff to evaluate their attitude towards referring patients for a history of penicillin allergy.
The authors found that 9.9% of patients (172/1738) had a record of penicillin allergy. In most cases, the history of the reaction was poorly detailed and even absent from the medical notes in 20.7% of the files. Half of patients with presumed penicillin allergy (87/172) had an indication for a beta-lactam antibiotic during their hospitalization. Fifty three (61%) received at least one dose of beta-lactam antibiotic (a penicillin in 25 patients) without any precaution. The history was not more detailed in those patients who received a beta-lactam antibiotic, and the decision-making process was documented in only 13 cases, of which 5 were based on a faulty rationale, which can be exemplified by the use, in one case, of cefazolin without any precaution because the patient had had a successful desensitization to ampicillin the year before. Thirty-four patients (39%) were treated with alternative antibiotics, mainly vancomycin and fluroquinolones, which led to an estimated additional cost averaging $326.50 (CAD) per patient compared to the preferred beta-lactam antibiotic. Only two patients were referred to an allergist after discharge for evaluation of their presumed penicillin allergy. A survey conducted among attending physicians revealed two key factors hampering optimal management of these patients: lack of allergists on staff and poor knowledge of penicillin allergy.
These findings show that, in the absence of allergists, management of patients with a history of penicillin allergy is frequently suboptimal and associated with increased antibiotic-related costs. Allergists have a key role to play to improve education on penicillin allergy and provide assistance to non-allergists in the management of patients with a history of penicillin allergy.
The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.