Objective: The aim of this study was to review cautionary statements regarding hypersensitivity to drugs with a moiety similar to sulfonamide on Japanese package inserts.
Methods: From approved drugs listed as of March 2015, we selected those with a moiety similar to sulfonamide and examined their therapeutic categories, together with the presence or absence, location, and wording of cautionary statements regarding usage, and matters pertaining to a history of drug hypersensitivity that was not limited to sulfonamide, on the package inserts.
Results: We extracted 73 drugs (65 components) that included a moiety similar to sulfonamide.  Their therapeutic categories were diverse, and 39 (53.4%) had cautionary statements about hypersensitivity caused by a moiety similar to sulfonamide.  Among these 39 drugs, the cautionary statements were located in different sections (Contraindication 31, Careful Administration 4, and Important Precautions 4).  The cautionary statements showed differences in wording according to the individual drugs or positions.  For 10 of the drugs, information pertaining to a history of drug hypersensitivity not limited to sulfonamide was provided.
Conclusion: Medical staff should recognize that package inserts are not standardized with regard to cautionary statements about hypersensitivity caused by moieties similar to sulfonamide, and that it is necessary to predict or judge the likelihood of cross-hypersensitivity reaction to such moieties on the basis of their chemical structure.  In addition, it is necessary to carefully observe the clinical condition of individual patients who are receiving drugs that have a moiety similar to sulfonamide.