Methadone oral tablets initially became available on the Japanese market in MAR－2013. Methadone, which has different pharmacological properties from other opioids including morphine, can cause serious adverse drug reactions such as respiratory depression and QT prolongation. One of the causes of these reactions is its extremely complex pharmacokinetics. Methadone is mostly metabolized in the liver, with a variety of metabolic enzymes, including cytochrome P450 (CYP) 3A4, CYP2B6, and CYP2D6, being involved. The characteristics of methadone include self-induction of metabolism, delayed excretion due to alkaline urine, and an extremely long half-life requiring a long time to achieve a steady state. Without a full understanding of its complex pharmacokinetics, the blood concentration of methadone is not maintained at a constant level, and serious adverse events could happen due to an unexpected increase in its blood concentration. Herein, for safe clinical use by physicians and pharmacists, we summarize the pharmacokinetics of methadone.

A 47-year-old male complaining of dyspnea and fever was admitted to our hospital and regurgitation of the aortic and mitral valves with mitral valve aneurysm due to infective endcarditis was diagnosed. The non-coronary and the right coronary cusps of the aortic valve had amount of vegetations, and also the anterior leaflet of the mitral valve had an aneurysm with vegetations. Both aortic and mitral valve replacement were performed. The postoperative clinical course was uneventful.

Primary malignant cardiac tumors are extremely rare. Among these, leiomyosarcoma are particularly exceptional and only about 20 surgically treated cases have been extensively described. We describe a case of right atrial leiomyosarcoma which was accidentally found by computed tomography. The tumor was surgically resected under extracorporeal circulation. Two months later the patient had cerebral hemorrhage due to a brain metastasis, which almost completely disappeared after irradiation. There was no other evidence of recurrence for 12 months after operation.

Objective: We conducted a questionnaire survey to comprehend the situation regarding the collection, provision, and utilization of drug safety information at hospitals.  In addition, we asked pharmaceutical companies how they select medical institutions to provide drug safety information.  We also investigated the current situation of information provision to Tokyo Medial Center by pharmaceutical companies.
Method: A questionnaire was mailed to all hospitals in Japan.  The survey was conducted between January 13 and February 10, 2011.  Moreover, we asked thirteen pharmaceutical companies by telephone and e-mail about the implementation status of the provision of information and performed a survey at Tokyo Medical Center on the current situation of information provision by pharmaceutical companies regarding revisions to precaution sections in package inserts.
Results: The results of the questionnaire survey (response rate: 41.2%) showed that the major information sources for hospitals were medical representatives (77.8%), Drug Safety Update (50.3%) and direct mails (49.3%).  Furthermore, in the case of drugs prescribed exclusively for extramural dispensing, fewer hospitals responded that medical representatives of the pharmaceutical companies provided drug safety information and more hospitals responded that they did not obtain any drug safety information at all, compared with drugs listed in the hospital formularies.
Conclusion: To minimize the risks of drugs, healthcare professionals must collect a wide range of drug safety information and must utilize this information in their medical practice.  Therefore, it is important that pharmaceutical companies and regulatory authorities make an effort to provide suitable information dissemination to medical institutions.  Furthermore, medical institutions must also strengthen their systems for collecting drug safety information and providing such information to healthcare professionals.