Purpose: We report a case with portal vein stenosis that showed unexpected drowsiness induced by oral administration of low dose opioid, suggesting elevation of opioid level in blood. Case report: A 60-year-old woman developed portal vein stenosis caused by postoperative local recurrence and lymph node metastasis after operation of lower bile duct carcinoma. Her doctor administrated 10mg/day of oral controlled-release oxycodone tablet to her and she became drowsy. Therefore, we started powdered form of oral sustained release morphine with 10mg/day and reduced the dose to 5 mg/day; however, her drowsiness persisted. Finally, the symptom was remarkably improved when the administration was changed to a transdermal fentanyl patch (12.5μg/h). Conclusion: Adequate observation is required for cases with reduction in portal blood flow at the time of oral opioid administration. Because oral opioid can escape from first pass effect of the liver and opioid level in blood will be increasing. Furthermore, it is suggested that change in administration method from oral route to percutaneous one may be effective for improvement of adverse effects involving increased opioid-level in blood. Palliat Care Res 2008; 3(2): 331-334

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.