Approach to the evaluation of adverse antibiotic reactions in patients with cystic fibrosis.

BACKGROUND: Adverse drug reactions (ADRs) to antibiotics in patients with cystic fibrosis (CF) are common and often mislabeled as allergies. The labeling of an antibiotic reaction as an allergy can lead to the use of antibiotics that are less efficacious, are more expensive, or have a greater risk of adverse effects.

OBJECTIVE: To establish a safe approach for the evaluation of ADRs to antibiotics in patients with CF to help clarify future use of these medications.

METHODS: Patients with CF whose antibiotic allergies were causing difficulty in their medical management were referred for an allergy evaluation that consisted of a thorough drug allergy history and antibiotic testing if appropriate. If the history was not consistent with a true hypersensitivity reaction (HSR) and test results were negative, the patient underwent a challenge to the offending agent(s) to rule out an HSR. Challenges were only performed if the medication was indicated for future use.

RESULTS: A total of 17 patients (mean age, 32.4 years) underwent a thorough allergy evaluation. A total of 17 antibiotic challenges were performed in 11 patients without a reaction consistent with an HSR or severe delayed reaction. Only 2 medications had a history consist with an HSR, and it was recommended that they undergo a desensitization procedure if the drug was required.

CONCLUSION: If treatment with appropriate antibiotics becomes difficult in patients with CF because of drug allergies, then referral to an allergist can help safely identify treatment options. Our findings suggest that a thorough evaluation by an allergy specialist can lead to more appropriate treatment options in patients with CF.