Knowledge and attitudes of American pharmacists concerning sulfonamide allergy cross-reactivity

Pharmacists are commonly confronted with patients with a history of sulfonamide allergy. Basic immunologic and clinical data suggest a low likelihood of a patient with a history of sulfonamide hypersensitivity developing an allergic reaction to a non-antimicrobial sulfonamide drug. We conducted a survey to describe the knowledge and attitudes of licensed pharmacists concerning sulfonamide allergy cross-reactivity.

A survey instrument was developed and sent to all licensed pharmacists in the state of Iowa. The survey recorded demographic information and included six patient scenarios designed to elicit responses concerning sulfonamide allergy cross-reactivity with a number of non-antimicrobial sulfonamides.

A total of 421 surveys were returned for a 39% response rate. There was a wide discrepancy in approaches to patients with a history of sulfonamide allergy prescribed a sulfonamide containing non-antibiotic. Differences depended on previous history of tolerating the medication in question, the degree of cautionary statements in product literature, and the familiarity the pharmacist had with the product.

Our survey suggests a significant diversity in knowledge and attitudes of pharmacists concerning cross-reactivity of sulfonamide antimicrobials and other drugs with a sulfonamide moiety. Depth of training in this area may be an associative factor.