Penicillin Allergy
Penicillin Allergy
I'm writing about a recently posted "Ask the Expert" column in reply to a question about penicillin allergy and cross-reactivity with sulfa drugs. Dr. Briceland is certainly correct that there is no immunologic cross-reactivity between penicillins and sulfa drugs. However, I think the reader's question may have been prompted by an article recently published in The New England Journal of Medicine (Strom BL, Schinnar R, Apter AJ, et al. Absence of cross-reactivity between sulfonamide antibiotics and sulfonamide nonantibiotics. N Engl J Med. 2003;349:1628-1635). In summary, there is evidence that patients with sulfonamide antibiotic allergy are at some increased risk for reactions from nonantibiotic sulfonamides. Strom and colleagues' study compared patients with (or without) presumed allergic reaction within 30 days of sulfonamide (or penicillin) antibiotic, who received nonantibiotic sulfonamide prescription greater than or equal to 60 days later. The study also compared patients with (or without) presumed allergic reaction within 30 days of a penicillin antibiotic, who received nonantibiotic sulfonamide prescription greater than or equal to 60 days later. Allergy to a sulfonamide antibiotic was a risk factor for a subsequent allergic reaction to a sulfonamide nonantibiotic (odds ratio of 2.8), but a history of penicillin allergy was at least as strong a risk factor (with an odds ratio of 3.9). The authors concluded that the association might be explained by a general predisposition to allergic reactions among certain patients rather than a specific cross-reactivity with drugs containing the sulfa moiety.
The authors went on to emphasize that prescribers should simply understand that patients with a history of any type of allergic reaction after the receipt of sulfonamides or penicillins may be at increased risk for reactions to other drugs, rather than consider sulfonamides a specific contraindication for prescribing a nonantibiotic sulfonamide derivative.
Nonetheless, such patients are likely placed at even greater risk for reaction by administering an immunologically cross-reactive agent, and it behooves a physician to be aware of immunologic cross-reactivity between agents and specific contraindications for use, as discussed by Dr. Briceland.
I'm writing about a recently posted "Ask the Expert" column in reply to a question about penicillin allergy and cross-reactivity with sulfa drugs. Dr. Briceland is certainly correct that there is no immunologic cross-reactivity between penicillins and sulfa drugs. However, I think the reader's question may have been prompted by an article recently published in The New England Journal of Medicine (Strom BL, Schinnar R, Apter AJ, et al. Absence of cross-reactivity between sulfonamide antibiotics and sulfonamide nonantibiotics. N Engl J Med. 2003;349:1628-1635). In summary, there is evidence that patients with sulfonamide antibiotic allergy are at some increased risk for reactions from nonantibiotic sulfonamides. Strom and colleagues' study compared patients with (or without) presumed allergic reaction within 30 days of sulfonamide (or penicillin) antibiotic, who received nonantibiotic sulfonamide prescription greater than or equal to 60 days later. The study also compared patients with (or without) presumed allergic reaction within 30 days of a penicillin antibiotic, who received nonantibiotic sulfonamide prescription greater than or equal to 60 days later. Allergy to a sulfonamide antibiotic was a risk factor for a subsequent allergic reaction to a sulfonamide nonantibiotic (odds ratio of 2.8), but a history of penicillin allergy was at least as strong a risk factor (with an odds ratio of 3.9). The authors concluded that the association might be explained by a general predisposition to allergic reactions among certain patients rather than a specific cross-reactivity with drugs containing the sulfa moiety.
The authors went on to emphasize that prescribers should simply understand that patients with a history of any type of allergic reaction after the receipt of sulfonamides or penicillins may be at increased risk for reactions to other drugs, rather than consider sulfonamides a specific contraindication for prescribing a nonantibiotic sulfonamide derivative.
Nonetheless, such patients are likely placed at even greater risk for reaction by administering an immunologically cross-reactive agent, and it behooves a physician to be aware of immunologic cross-reactivity between agents and specific contraindications for use, as discussed by Dr. Briceland.
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