Manabu Akazawa

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.

Economic impact of switching to fixed-dose combination therapy for Japanese hypertensive patients: a retrospective cost analysis

BackgroundThe prescription of fixed-dose combinations (FDC) of antihypertensive drugs has increased rapidly since the relaxation of the prescription-term restriction.In this study, we used the opportunity of this policy change in Japan as an instrument to assess the causal impact of switching to FDC on hypertensive treatment costs.MethodsClaims data from 64 community pharmacies located in Tokyo were used to identify hypertensive patients under continuous treatment with angiotensin-receptor blockers (ARBs). Patients switching to FDC between December 2010 and April 2011 were compared to patients who did not receive FDC (control group). Changes in annual antihypertensive drug costs were compared using a difference-in-differences approach to adjust for patient characteristics and use of concomitant medication. Subpopulation analyses were also performed, taking into account pre-index treatment patterns and prescribers’ characteristics.ResultsThere were 542 patients who switched to FDC and 9664 patients in the control group. No significant differences were observed between the 2 groups, except for antihypertensive drug use patterns before the policy change and prescribers’ characteristics. The switch to FDC was associated with an annual saving of 10,420 yen (US

A cross-sectional investigation of the quality of selected medicines in Cambodia in 2010

112.0) in antihypertensive drug costs. Approximately 20% of the FDC patients, however, switched from ARB alone, and their drug costs increased by 2376 yen (US

Effect of abatacept on the immunogenicity of 23-valent pneumococcal polysaccharide vaccination (PPSV23) in rheumatoid arthritis patients.

25.5).ConclusionsFor hypertensive patients who required ARB-based combination therapy, switching to FDC drugs had a significant cost-saving effect. However, the policy change of relaxing the prescription-term restriction could encourage aggressive treatment, i.e., switching to a combination therapy from monotherapy, regardless of medical conditions. Further research is required to evaluate the possible negative aspects of FDC drugs.

The 23-valent pneumococcal polysaccharide vaccine in patients with rheumatoid arthritis: a double-blinded, randomized, placebo-controlled trial.

BackgroundAccess to good-quality medicines in many countries is largely hindered by the rampant circulation of spurious/falsely labeled/falsified/counterfeit (SFFC) and substandard medicines. In 2006, the Ministry of Health of Cambodia, in collaboration with Kanazawa University, Japan, initiated a project to combat SFFC medicines.MethodsTo assess the quality of medicines and prevalence of SFFC medicines among selected products, a cross-sectional survey was carried out in Cambodia. Cefixime, omeprazole, co-trimoxazole, clarithromycin, and sildenafil were selected as candidate medicines. These medicines were purchased from private community drug outlets in the capital, Phnom Penh, and Svay Rieng and Kandal provinces through a stratified random sampling scheme in July 2010.ResultsIn total, 325 medicine samples were collected from 111 drug outlets. Non-licensed outlets were more commonly encountered in rural than in urban areas (p < 0.01). Of all the samples, 93.5% were registered and 80% were foreign products. Samples without registration numbers were found more frequently among foreign-manufactured products than in domestic ones (p < 0.01). According to pharmacopeial analytical results, 14.5%, 4.6%, and 24.6% of the samples were unacceptable in quantity, content uniformity, and dissolution test, respectively. All the ultimately unacceptable samples in the content uniformity tests were of foreign origin. Following authenticity investigations conducted with the respective manufacturers and medicine regulatory authorities, an unregistered product of cefixime collected from a pharmacy was confirmed as an SFFC medicine. However, the sample was acceptable in quantity, content uniformity, and dissolution test.ConclusionsThe results of this survey indicate that medicine counterfeiting is not limited to essential medicines in Cambodia: newer-generation medicines are also targeted. Concerted efforts by both domestic and foreign manufacturers, wholesalers, retailers, and regulatory authorities should help improve the quality of medicines.

Drug Utilization Reviews by Community Pharmacists in Japan: Identification of Potential Safety Concerns through the Brown Bag Program

IntroductionPatients with rheumatoid arthritis (RA) treated with abatacept (ABT) are at increased risk for vaccine-preventable infections. The aim of the present study is to evaluate the humoral response to 23-valent pneumococcal polysaccharide (PPSV23) vaccination in RA patients receiving ABT.MethodsThe immunogenicity study was nested within a randomized, double-blind placebo-controlled study, designed to evaluate the efficacy of the PPSV23. PPSV23 was given to 111 RA patients, who were classified into three groups: RA control (n = 35), methotrexate (MTX) alone (n = 55), and ABT (n = 21). Before and 4–6 weeks after vaccination, we measured the patients’ concentrations of antibodies against pneumococcal serotypes 6B and 23F using an enzyme-linked immunosorbent assay and determined their antibody functionality using a multiplexed opsonophagocytic killing assay, reported as the opsonization index (OI).ResultsThe pneumococcal serotype-specific IgG concentrations and OIs were both significantly increased in all treatment groups in response to PPSV23 vaccination. In the ABT group, the IgG responses for the 6B serotype were lower compared with those in the MTX alone or control groups, whereas the OI responses were similar to those in the other two groups. In a subgroup analysis, the pneumococcal serotype-specific IgG responses were significantly lower in both serotypes (6B and 23F) in the ABT/MTX group; however, the OI responses in the ABT group were not different from the control group. There was no association between the pneumococcal serotype-specific IgG and OI responses for the 6B serotype in patients receiving ABT in contrast to the control or MTX alone patients. No severe adverse effects were observed in any of the treatment groups.ConclusionsOI responses indicate antibody functionality rather than simply their amount, so the similarity of these measurements between all three groups suggests that RA patients receiving ABT still benefit from receiving the PPSV23 vaccination, even though they produce less IgG in response to it. The results suggest an influence of ABT on the humoral response to PPSV23 vaccination under MTX treatment; however, preserved opsonin responses are expected in RA patients treated with ABT plus MTX.Trial registrationUniversity Hospital Medical Information Network Clinical Trials Registry: UMIN000009566. Registered 12 December 2012.

Opsonic and Antibody Responses to Pneumococcal Polysaccharide in Rheumatoid Arthritis Patients Receiving Golimumab Plus Methotrexate.

BackgroundPneumococcal pneumonia is the most frequent form of pneumonia. We herein assessed the effectiveness of the 23-valent pneumococcal polysaccharide vaccine (PPSV23) in the prevention of pneumonia overall in rheumatoid arthritis (RA) patients at risk for infections. We hypothesized that PPSV23 vaccination is superior in preventing pneumococcal pneumonia compared with placebo in RA patients.MethodsA prospective, multicenter, double-blinded, randomized, placebo-controlled (1:1) trial was conducted across departments of rheumatology in Japanese National Hospital Organization hospitals. RA patients (n = 900) who had been treated with biological or immunosuppressive agents were randomly assigned PPSV23 or placebo (sodium chloride). The primary endpoints were the incidences of all-cause pneumonia and pneumococcal pneumonia. The secondary endpoint was death from pneumococcal pneumonia, all-cause pneumonia, or other causes. Cox regression models were used to estimate the risk of pneumonia overall for the placebo group compared with the vaccine group.ResultsSeventeen (3.7%) of 464 patients in the vaccine group and 15 (3.4%) of 436 patients in the placebo group developed pneumonia. There was no difference in the rates of pneumonia between the two study groups. The overall rate of pneumonia was 21.8 per 1000 person-years for patients with RA. The presence of interstitial pneumonia (hazard ratio: 3.601, 95% confidence interval: 1.547–8.380) was associated with an increased risk of pneumonia in RA patients.ConclusionPPSV23 does not prevent against pneumonia overall in RA patients at relative risk for infections. Our results also confirm that the presence of interstitial lung disease is associated with pneumonia in Japanese patients with RA.Trial registrationUMIN-CTR UMIN000009566. Registered 17 December 2012.

Considering economic analyses in the revision of the preventive vaccination law: A new direction for health policy-making in Japan?

OBJECTIVES Pharmacy-based drug utilization reviews were conducted through the Brown Bag program to understand drug-use patterns, identify potential safety concerns, and provide appropriate consultation for elderly individuals. METHODS Community pharmacists in Hiroshima, Japan, participated in this review program from October to December 2009. Elderly individuals, 65 years or older, were recruited from community events or at pharmacies and were asked to bring all their prescription and nonprescription drugs including over-the-counter drugs and dietary supplements to the program. Pharmacists reviewed the medications and their usages and gave appropriate feedback if medications were used incorrectly, had potential interactions, or had safety concerns. The relationships among medication usage, participant responses, and potential safety concerns were analyzed by using logistic regression models. In addition, contraindications, duplicate medications, and potentially inappropriate medications were descriptively analyzed. RESULTS Drug utilization reviews were conducted on 508 elderly participants at 177 community pharmacies. Of the 508 participants, 53% were 75 years old or older and 34% were men. Twenty-four percent of the elderly participants used prescription drugs only, and 73% used both prescription and nonprescription drugs. Pharmacists offered feedback to 250 participants (49%) concerning the risk of duplication/interaction, possible adverse drug reaction that can be averted, inappropriate/unnecessary medication, nonadherence, and overdose. Two cases of contraindicated drugs, 3 cases of duplicate medications, and 327 cases of potentially inappropriate medications were identified. CONCLUSIONS The drug-use patterns among elderly individuals were identified. This medication review program conducted at community pharmacies was a useful approach to reduce concerns among users and prevent safety problems.

Antihypertensives prescribed for pregnant women in Japan: Prevalence and timing determined from a database of health insurance claims

AbstractVaccination against Streptococcus pneumoniae is recommended for rheumatoid arthritis (RA) patients receiving immunosuppressive treatments. The objective of this study was to evaluate the humoral response to 23-valent pneumococcal polysaccharide vaccination (PPSV23) in RA patients receiving methotrexate (MTX) alone or in combination with a tumor necrosis factor inhibitor, golimumab (GOM).PPSV23 was given to 114 RA patients, who were classified into three groups: RA control (n = 35), MTX alone (n = 55), and GOM + MTX (n = 24). Before and 4 to 6 weeks after vaccination, concentrations of antibodies against pneumococcal serotypes 6B and 23F were measured using an enzyme-linked immunosorbent assay and antibody functionality was determined using a multiplexed opsonophagocytic killing assay, reported as the opsonization index (OI).The IgG concentrations and OIs were both significantly increased in all treatment groups in response to PPSV23 vaccination. In the GOM + MTX group, the IgG responses were lower than those in the MTX alone or control groups, whereas the OI responses were similar to those in the other 2 groups. Furthermore, discrepancies between the IgG and OI responses were found in GOM + MTX group. No severe adverse effect was observed in any treatment groups.OI responses indicate that antibody functionality rather than antibody quantity is important. The similarity of these measurements between all 3 groups suggests that RA patients receiving MTX + GOM still benefit from receiving the PPSV23 vaccination, even though they produce less IgG in response to it. These results can help clinicians to better schedule and evaluate pneumococcal vaccination for RA patients.

Cost-Minimization Analysis of Deep-Brain Stimulation Using National Database of Japanese Health Insurance Claims: COST-MINIMIZATION OF DBS IN JAPAN

Evidence of a significant vaccine policy shift can be witnessed not only in the number of new vaccines available in Japan but also in the way that vaccine policy is being formulated. In 2010, policy makers decided for the first time ever to commission economic analyses as a reference in their consideration of subsidy allocation. This research offers a first hand account of the recent changes in vaccine policies by examining the decision-making process from the perspective of the researchers commissioned to perform the economic evaluations. In order to understand the vaccine policy-making process, a review was made of all the documents that were distributed and discussed during the government committee meetings from February 2010 when the revision of the Preventive Vaccination Law was initially proposed to May 2012 when the final recommendations were made. Economic evaluations were conducted for seven vaccines under consideration in the routine immunization program (Haemophilus influenzae type b or Hib, pneumococcal disease for children and adults, human papillomavirus, varicella, mumps, and hepatitis B). All were cost-effective options, except the Hib and hepatitis B vaccines. Nonetheless, all the vaccines were recommended equally for inclusion in the routine immunization program. While it is significant that policy-makers decided to commission economic assessments at all, various issues remain regarding the influence of external pressure, the choice of evaluation methods and the implications of using cost-effectiveness analyses on the future of Japanese health policy-making.