Establishment of the MID-NET® medical information database network as a reliable and valuable database for drug safety assessments in Japan.

PURPOSE: To establish a new medical information database network (designated MID-NET® ) to provide real-world data for drug safety assessments in Japan. METHODS: This network was designed and developed by the Ministry of Health, Labour and Welfare and the Pharmaceuticals and Medical Devices Agency in collaboration with 23 hospitals from 10 healthcare organizations across Japan. MID-NET® is a distributed and closed network system that connects all collaborative organizations through a central data center. A wide variety of data are available for analyses, including clinical and administrative information. Several coding standards are used to standardize the data stored in MID-NET® to allow the integration of information originating from different hospitals. A rigorous and consistent quality management system was implemented to ensure that MID-NET® data are of high quality and meet Japanese regulatory standards (good post-marketing study practice and related guidelines). RESULTS: MID-NET® was successfully established as a reliable and valuable medical information database and was officially launched in April 2018. High data quality with almost 100% consistency was confirmed between original data in hospitals and the data stored in MID-NET® . A major advantage is that approximately 260 clinical laboratory test results are available for analysis. CONCLUSIONS: MID-NET® is expected to be a major data source for drug safety assessments in Japan. Experiences and best practices established in MID-NET® may provide a model for the future development of similar database networks.

The utilization and challenges of Japan's MID-NET® medical information database network in postmarketing drug safety assessments: A summary of pilot pharmacoepidemiological studies.

PURPOSE: To examine the potential role of Medical Information Database Network (MID-NET® ), a newly established Japanese medical information database network, in postmarketing drug safety assessments through the characterization of its advantages and limitations in five pilot studies. METHODS: The pilot studies were designed to address three major objectives in postmarketing drug safety assessments, ie, the examination of actual drug utilization, the impact of safety-related regulatory actions, and drug-associated risks. The five studies were conducted on the following topics: (a) utilization of codeine-containing products and its relationship with respiratory depression, (b) impact of a Dear Healthcare Professional letter on hypocalcemia incidence associated with denosumab (Ranmark® ) use, (c) risk of acute myocardial infarction associated with antidiabetic drug use, (d) risk of glucose metabolism disorders associated with atypical antipsychotic drug use, and (e) prospective monitoring of abnormal laboratory test results during new drug prescriptions. RESULTS: The pilot studies were successfully conducted and demonstrated the value of MID-NET® in postmarketing drug safety assessments. In particular, the ability to utilize laboratory test results as objective clinical indicators is a major advantage of this database. Potential limitations include a relatively small sample size and a lack of patient-level data linkages among hospitals. CONCLUSIONS: MID-NET® was confirmed to be a valuable database for postmarketing drug safety assessments. The use of laboratory test results to define clinical outcomes may allow more objective and accurate analyses to be conducted. These studies furthered our understanding of the characteristics of MID-NET® , including its advantages and limitations.

Reduced Clearance of Phenobarbital in Advanced Cancer Patients near the End of Life.

BACKGROUND AND OBJECTIVES: Little is known about the pharmacokinetics of phenobarbital in terminally ill cancer patients. We investigated whether phenobarbital clearance alters depending on the length of survival. METHODS: We retrospectively reviewed the clinical, laboratory, and therapeutic drug monitoring (TDM) records of patients who received parenteral or oral phenobarbital for 21 consecutive days or longer between 2000 and 2016. Patients were divided into non-cancer and cancer groups. Cancer patients were further stratified according to the survival interval after TDM: those who survived > 3 months were classified as long-surviving and the remainders short-surviving cancer patients. Phenobarbital clearance (CLPB) was calculated at steady state. Multiple comparisons of median CLPB were conducted among the three groups. RESULTS: Data were collected from 44 non-cancer patients and 34 cancer patients comprising 24 long-surviving and 10 short-surviving cancer patients. Among 10 short-surviving cancer patients, 4 had hepatic metastasis. Median CLPB (range) in short-surviving cancer patients [0.076 (0.057‒0.114) L/kg/day] was significantly (p < 0.05) lower than that in non-cancer patients [0.105 (0.060‒0.226) L/kg/day] and in long-surviving cancer patients [0.100 (0.082‒0.149) L/kg/day]. CONCLUSION: Terminally ill patients with advanced cancer may have reduced CLPB, thereby TDM is recommended for these patients particularly near the end of life.

[Current Status and Issues of Electronic Information Provision for Risk Minimization: Coordination between Electronic Medicine Notebook and Patient Drug Information].

　In the collaboration between community pharmacies and hospitals or clinics, the use of electronic medicine notebook may allow information sharing, including among out-of-network hospitals, clinics, and community pharmacies. For risk minimization, mobile or smart phones, which patients always carry with them, should be used as a tool allowing drug information to be accessed at any time. An advantage of the electronic conversion of patient drug information is that it allows patients not only to obtain round-the-clock information on drugs, etc. that they are receiving but also to check patient-oriented information selected and made easier to understand by pharmacists. In the collaboration between community pharmacies and hospitals or clinics, if, for example, patient discharge summaries are conveyed to community pharmacies via electronic medicine notebook, patients will feel reassured about the medical alliance and place more trust in pharmacists overall. This can improve patient drug awareness, thus contributing effectively to risk minimization. Drug information in electronic medicine notebook with 24-h access requires not only patients but also pharmacists to be proactive in its use. In addition, a system to facilitate the proactive use of that information needs to be established. For the electronic conversion of patient drug information and the establishment of a system promoting electronic medicine notebook use, the current status and issues need to be thoroughly examined from the viewpoint of risk communication.

Meta-analysis on the Influence of Antifungal Spectrum on Effectiveness of Empirical Antifungal Therapy for Febrile Neutropenia.

We conducted a meta-analysis to investigate the influence of antifungal spectrum on the effectiveness and adverse events of empirical antifungal therapy for febrile neutropenia. We searched PubMed and Cochrane Central Register of Controlled Trials (Central), and identified randomized controlled trials reporting mortality, efficacy, adverse events, and hepatic and renal dysfunction. Five trials assessed the efficacy and adverse events of agents with antifungal spectrum covering and those not covering Aspergillus. There were no differences in mortality [risk ratio (RR); 0.79, 95% confidence interval (Cl); 0.60-1.02], efficacy ratio (RR; 1.01, 95%Cl; 0.91-1.12), adverse event ratio (RR; 0.23, 95%Cl; 0.04-1.23), and hepatic dysfunction ratio (RR; 0.81, 95%Cl; 0.59-1.12) between two groups. Antifungals with no activity against Aspergillus were associated with lower renal dysfunction ratio (RR; 0.27, 95%Cl; 0.10-0.71). Five trials compared agents with antifungal spectrum covering versus those not covering Mucor. There were no difference in mortality (RR; 1.24, 95%Cl; 0.98-1.57), efficacy ratio (RR; 1.09, 95%Cl; 0.91-1.30), and hepatic dysfunction ratio (RR; 0.98, 95%Cl; 0.66-1.45) between two groups. Antifungals with no activity against Mucor were associated with lower adverse event ratio (RR; 0.60, 95%Cl; 0.47-0.77) and renal dysfunction ratio (RR; 0.25, 95%Cl; 0.13-0.49). Presence or absence of activity against Aspergillus or Mucor is not associated with mortality or efficacy ratio. Amphotericin B with activity against Aspergillus and Mucor has a higher adverse event ratio. Depending on the case, selection of antifungal drugs considering efficacy and side effects is necessary.

Induration at Injection or Infusion Site May Reduce Bioavailability of Parenteral Phenobarbital Administration.

BACKGROUND: Phenobarbital is well tolerated and effective for controlling agitation or preventing convulsion at the end of life. No information is available concerning parenteral bioavailability of phenobarbital when induration develops at the injection or infusion site. We investigated whether induration at injection or infusion site is related to phenobarbital bioavailability via parenteral routes of continuous subcutaneous infusion and intermittent subcutaneous or intramuscular injection. METHODS: A retrospective analysis was conducted on the medical data obtained from 18 patients who received chronic subcutaneous or intramuscular injections of phenobarbital for the prevention of convulsions and underwent plasma concentration monitoring of the drug. Patients whose concomitant medications were altered during the observation periods were excluded from the analysis. Comparisons were performed for concentration/dose (C/D) ratios obtained from patients with induration at injection or infusion sites (induration group, n = 6) and those without induration (noninduration group, n = 12). P < 0.05 was considered statistically significant. RESULTS: The induration group showed significantly reduced C/D ratio compared with the noninduration group [median (range): 0.131 (0.114-0.334) versus 0.219 (0.180-0.322) d/L, P < 0.05). Assuming that systemic clearance was constant in our patients, changes in the C/D ratio would have contributed to 40% (median) reduction in bioavailability of the drug from the injection or infusion site. CONCLUSIONS: Our data suggest that absolute bioavailability of phenobarbital may be reduced when induration develops at the injection or infusion site in patients treated parenterally by continuous subcutaneous infusion or intramuscular injection.

Eculizumab Dosing Intervals Longer than 17 Days May Be Associated with Greater Risk of Breakthrough Hemolysis in Patients with Paroxysmal Nocturnal Hemoglobinuria.

Eculizumab given bi-weekly is widely recommended for the treatment of paroxysmal nocturnal hemoglobinuria (PNH). We undertook a retrospective analysis on the medical records of 763 dosings of 14 PNH patients to investigate whether a threshold would exist in dosing intervals associated with breakthrough hemolysis. We identified 12 events of breakthrough hemolysis in 4 patients. Multivariate logistic regression and receiver operating characteristics (ROC) analysis revealed a significant association between increased risk of breakthrough hemolysis and prolonged dosing intervals of 17 days or more and concomitant inflammation: odds ratios (OR) and 95% confidence intervals (CIs) were 1.6 (1.3-2.0, p<0.01) and 5.5 (1.3-22.8, p=0.02), respectively. ROC analysis showed that the best cut-off dosing interval discriminating breakthrough hemolysis was 16.5 days. We consider that eculizumab dosing intervals longer than 17 days may be associated with an increased risk for developing breakthrough hemolysis in patients with PNH.

[Influence of systemic inflammatory response syndrome on the pharmacokinetics of vancomycin].

Therapeutic drug monitoring (TDM) of vancomycin (VCM) is recommended to minimize its nephrotoxicity and maximize efficacy. Recently, the concept of systemic inflammatory response syndrome (SIRS) has been introduced to describe a clinical state resulting from the actions of complex intrinsic mediators in an acute-phase systemic response. However, there are few reports on the pharmacokinetics of VCM in patients with SIRS. This study investigated the effect of SIRS on the pharmacokinetics of VCM by analyzing the predictability of TDM and pharmacokinetic parameters in 31 non-SIRS patients and 52 SIRS patients, with stratification by SIRS score. The mean prediction error (ME) and mean absolute prediction error in SIRS score 2 and 3 patients differed from those in non-SIRS patients. The ME in the score 4 group showed a negative value. In the comparison of pharmacokinetic parameters by SIRS score, a significantly lower CL(vcm) value was observed at score 4 compared with scores 2 and 3, a higher Vd value was observed at score 4 compared with non-SIRS and at score 3, and a longer T1/2 was observed at score 2. In the comparison of patient characteristics by SIRS score, albumin, aspartate aminotransferase, and alanine aminotransferase levels showed differences among the scores. However, no correlation was observed between VCM pharmacokinetics and these three laboratory parameters. These findings suggest that the pharmacokinetics of VCM may be affected by the pathology of SIRS rather than by patient characteristics.

[Review of drug information provided to patients from the viewpoint of hospital pharmacists].

Risks for patients and consumers can be minimized depending on how they are provided appropriate drug information. Therefore, from the viewpoint of hospital pharmacists, I would like to report on how information should be provided in order to minimize patient risk. For example, there is an ongoing opinion that the provision of easy-to-understand drug information to patients and consumers "does not appear necessary". The reasons for this include the following: Because the level of understanding varies greatly among patients, it is difficult to define what "easy-to-understand" information entails; rather, it may cause misunderstanding. These problems occur repeatedly if they are resolved by individual institutions. Therefore, it is essential to standardize the drug information provided to patients, that is, to establish a system to transmit drug information to patients and consumers. Regardless of whether the development of a hospital information system is in progress or not, it can be said that the development of such information systems is gradually spreading outside of hospitals and the situation is changing. From the viewpoint of patients, medical services are not limited to those from hospitals. Patient-centered collaboration between hospitals/clinics and pharmacies (but not the collaboration between hospital pharmacists and community pharmacists (why not?)) can provide good medical services only if patient information is shared. It is essential to establish a system for providing a drug guide for patients, in order to have patients understand drug information. The preparation of Drug Information for Patients would provide health care specialists a communication tool that helps minimize patient risk.

A prospective stratified case-cohort study on statins and multiple adverse events in Japan.

PURPOSE: To assess the association between statins and diverse adverse events in Japanese population. METHODS: New users of statin who started statin after 6-month period of non-use were identified in 68 hospitals between January 2008 and July 2010. In addition to the random sample subcohort, we selected additional subcohort members to make the stratified sample subcohort have at least one patient in all subgroups stratified by each combination of statin and hospital. By abstraction from medical records, detailed information was obtained for all potential cases and pre-selected subcohort members. The event review committee consisting of 3 specialists judged whether possible cases met the definition of one of the adverse events of interest, and for adjudicated cases the committee further judged whether statin was a certain, probable or possible cause of the occurrence of the event. Adjusted for covariates including age, gender, status of "switcher", use of high daily dose and comorbidities at baseline, hazard ratio (HR) was estimated by the Cox proportional hazards model with Barlow's weighting method. Data were also analyzed by the method proposed by Breslow in 2009. RESULTS: A total of 6,877 new users of a statin were identified (median age: 66 years; males: 52%). The hazard ratios of increase in serum creatinine for atorvastatin and fluvastatin have wide confidence intervals, but both of the point estimates were around 2.5. Estimates of hazard ratios by the method of Barlow (1999) were similar to those by the method of Breslow (2009). CONCLUSIONS: Use of statin was not associated with a significant increased risk for renal, liver and muscle events. However, the hazard ratio of increase in serum creatinine tended to be high with atorvastatin and fluvastatin to require further studies.

Assessment of statin-associated muscle toxicity in Japan: a cohort study conducted using claims database and laboratory information.

OBJECTIVE: To estimate the incidence of muscle toxicity in patients receiving statin therapy by examining study populations, drug exposure status and outcome definitions. DESIGN: A retrospective cohort study. SETTING: 16 medical facilities in Japan providing information on laboratory tests performed in and claims received by their facilities between 1 April 2004 and 31 December 2010. PARTICIPANTS: A database representing a cohort of 35 903 adult statin (atorvastatin, fluvastatin, pitavastatin, pravastatin, rosuvastatin and simvastatin) users was studied. Use of interacting drugs (fibrates, triazoles, macrolides, amiodarone and ciclosporin) by these patients was determined. MAIN OUTCOME MEASURE: Statin-associated muscle toxicity (the 'event') was identified based on a diagnosis of muscle-related disorders (myopathy or rhabdomyolysis) and/or abnormal elevation of creatine kinase (CK) concentrations. Events were excluded if the patients had CK elevation-related conditions other than muscle toxicity. Incidence rates for muscle toxicity were determined per 1000 person-years, with 95% CI determined by Poisson regression. RESULTS: A total of 18 036 patients accounted for 42 193 person-years of statin therapy, and 43 events were identified. The incidence of muscle toxicity in the patients treated with statins was 1.02 (95% CI 0.76 to 1.37)/1000 person-years. The estimates varied when outcome definitions were modified from 0.09/1000 person-years, which met both diagnosis and CK 10× greater than the upper limit of normal range (ULN) criteria, to 2.06/1000 person-years, which met diagnosis or CK 5× ULN criterion. The incidence of muscle toxicity was also influenced by the statin therapies selected, but no significant differences were observed. Among 2430 patients (13.5%) received interacting drugs with statins, only three muscle toxicity cases were observed (incidence: 1.69/1000 person-years). CONCLUSIONS: This database study suggested that statin use is generally well tolerated and safe; however, the risk of muscle toxicity related to the use of interacting drugs requires further exploration.

[Investigation of the factors that contribute to the onset of insomnia in hypertensive patients by using a post-marketing surveillance database].

Many factors contribute to the onset of insomnia. However, few studies have identified the factors related to the onset of insomnia in hypertensive patients. We conducted a pharmacoepidemiologic study to examine the incidence of insomnia in hypertensive patients by using a post-marketing surveillance database. The insomnia onset was defined as the time of first prescription of hypnotics. The insomnia incidence rate in hypertensive patients under antihypertensive therapy was 0.77/100 person-years. The median insomnia onset date was 5 weeks. The insomnia type in 50.2% of the patients was difficulty in initiating sleep. We assessed the factors contributing to insomnia by using a nested case-control design. We selected 10 time-matched controls for every case. The hypotensive effect induced by antihypertensive therapy on the case group was lesser than that on the control group (p<0.01). The odds ratios (ORs) were estimated using multivariate conditional logistic regression. The factors contributing to insomnia onset were α blockers (OR, 2.38; 95% confidence interval [CI], 1.14-4.98), ß blockers (OR, 1.54; 95% CI, 0.99-2.39), and calcium channel blockers (OR, 0.62; 95% CI, 0.43-0.90) compared with angiotensin-converting enzyme inhibitors; female sex (OR, 1.76; 95% CI, 1.27-2.44); complication of gastric/duodenal disorders (OR, 2.35; 95% CI, 1.14-4.86) or musculoskeletal system/connective tissue disorders (OR, 2.43; 95% CI, 1.23-4.79); and concomitant antihypertensive therapy (OR, 0.44; 95% CI, 0.31-0.63). This study identified the potential factors that may help to predict insomnia onset in hypertensive patients under antihypertensive therapy.

Urinary lipocalin-type prostaglandin D synthase: a potential marker for early gentamicin-induced renal damage?

Urinary excretion of lipocalin-type prostaglandin D synthase (L-PGDS) has been suggested to be a useful biomarker of early diabetic nephropathy. We studied whether L-PGDS is also a marker of gentamicin (GM)-induced renal damage in the "creatinine-blind" range. A prospective study was conducted in 6 patients who were given long-term intravenous administration of GM (18-42 days in combination with a beta-lactam/carbapenem antibiotic or vancomycin) for the treatment of infective endocarditis. Urinary excretions of L-PGDS, beta2-microglobulin, and N-acetyl-beta-D-glucosaminidase were measured in the early (within 10 days from commencement) and late (thereafter) phases of GM therapy. Systemic clearance of GM (CLGM) and creatinine clearance (CLcr) was also measured concomitantly. CLGM was reduced significantly (P < 0.05) by 10% from the early to late treatment phase, whereas urinary L-PGDS excretion showed a significant (P < 0.05) increase (from 7.3 +/- 4.6 to 8.7 +/- 5.0 mg/g creatinine, mean +/- SD) concomitantly. In contrast, no significant changes were observed for urinary beta2-microglobulin and N-acetyl-beta-D-glucosaminidase concentrations. In conclusion, urinary L-PGDS may be a promising biomarker for the early phase of GM-induced renal impairment.

Relation between drug-induced taste disorder and chelating behavior with zinc ion; statistical approach to the drug-induced taste disorder, part II.

There are many reports that the drug-induced taste disorder is ascribable to the chelate reaction of a drug with zinc ion and the following zinc deficiency. As a quantitative measure of the chelating ability of drugs with zinc ions, the chelating ability was estimated from the electrode potential change of the Zn2+/Zn(Hg) system during the addition of a drug. The electrode potential was measured in a water-N,N-dimethylformamide mixed solution and in an aqueous solution depending on the solubility of the drugs. The observed electrode potential change showed a positive correlation to the frequency of the drug-induced taste disorder that was supplied from the manufacturer of the original drug. The regression analysis was carried out assuming that the frequency of the taste disorder and the electrode potential change was linear. The F-values, p-values, and R2-values were 4.29, 0.13, 0.589, and 4.15, 0.13, 0.580, respectively. The positive correlation between the drug-induced taste disorder and the electrode potential change appeared evident if the uncertainty in the frequency of the taste disorder was taken into consideration. Thus the assumption of the zinc ion chelating mechanism on the drug-induced disorder was also evident except for cisplatin. The frequency of the drug-induced taste disorder of bezafibrate was estimated to be 0.4--0.5 from the regression analysis.

Reduced vancomycin clearance despite unchanged creatinine clearance in patients treated with vancomycin for longer than 4 weeks.

Creatinine clearance-based nomograms are used routinely during the early phase of vancomycin therapy for individualizing doses. The authors studied whether such nomograms are also valid for patients receiving the drug for an extended period of longer than 4 weeks. A retrospective analysis was conducted on the therapeutic drug monitoring data obtained from 85 patients who received an intermittent intravenous infusion of vancomycin. The patients were allocated to one of five groups according to the length of drug exposure: Group 1 (4-7 days; n = 31), Group 2 (8-14 days; n = 22), Group 3 (15-21 days; n = 13), Group 4 (22-28 days; n = 8), and Group 5 (longer than 29 days; n = 11). Systemic clearance of vancomycin and estimated creatinine clearance calculated by Cockcroft & Gault's formula obtained from Groups 2 through 5 were compared with those from Group 1. Patients who had received vancomycin for longer than 4 weeks (Group 5) showed a significant (P < 0.05) reduction in systemic clearance of vancomycin by 50% compared with Group 1, whereas creatinine clearance remained unchanged. This study demonstrated that prolonged administration of vancomycin for over 4 weeks may result in a more pronounced reduction in systematic clearance of vancomycin than creatinine clearance. Our data suggest that creatinine clearance-based nomograms for individualizing vancomycin doses should be used with caution in patients who require substantially prolonged drug exposure such as those with infective endocarditis.

Statistical approach to drug-induced taste disorders based on zinc chelating ability.

Various drug-induced taste disorders have been ascribed to zinc deficiency in serum. Assuming that the zinc deficiency is caused by the chelating reaction of zinc ions with drugs, the electrode potential of the Zn(2+)/Zn(Hg) system was measured in the presence of drugs in water, ethanol, and N,N-dimethylformamide (DMF). The zinc-chelating ability was estimated based on the potential change Delta E(2) with the addition of a drug. A large potential change suggesting potent chelating ability was observed in penicillamine, furosemide, and ibuprofen in ethanol and in fluorouracil, acetazolamide, and bezafibrate in DMF. Multiple regression analysis was used to evaluate the observed Delta E(2) in mV to represent chelating ability. The regression equation to estimate the frequency of taste disorders was deduced from Delta E(2), and frequency of four drugs appeared in package inserts and interview forms. According to the regression equation, the frequency of taste disorders was successfully estimated for 14 drugs examined in this study. The result was examined in a clinical case.