Abstract:
The professional information leaflets of three locally available specific cyclooxygenase-2 inhibitors indicate that these
drugs are contraindicated in persons with a known allergy to sulfonamides. There are many concerns about cross-allergenicity
between sulfonamide antibiotics and non-antibiotic sulfonamide-containing drugs including the sulfones, and
these concerns continue to complicate drug therapy. Several elegant investigations have demonstrated lack of interaction
between the sulfonamide group and either cellular or humoral immunity. The immunologic determinant of type I
immunologic responses to sulfonamide antibiotics are the N1 heterocyclic ring, and non-antibiotic sulfonamides
including the sulfones lack this structural feature. Reactive sulfonamide metabolites contribute many non-type I hypersensitivity
responses to sulfonamide antibiotics. Metabolite formation demonstrates stereospecificity to the N4 amino
nitrogen of the sulfonamide antibiotics, a structure not found on any non-antibiotic sulfonamide drugs and is also lacking
in the sulfones. Apparent cross-reactivity responses to sulfonamide-containing drugs likely represent multiple concurrent,
rather than linked, drug hypersensitivities.
