Relationship between polypharmacy and adverse events.

A retrospective data analysis was performed to investigate the association between polypharmacy and adverse events using three different spontaneous adverse event reporting system databases. Multivariate logistic regression analyses were performed to investigate the association between the number of drugs and adverse events, including hepatic disorders, renal disorders, hypersensitivity, and extrapyramidal syndrome. The results showed that the risk of hepatic and renal disorders increased with the number of drugs. Thus, decreasing the number of drugs may reduce the risk of hepatic and renal disorders. Furthermore, attention should be given to specific drugs that may cause hypersensitivity and extrapyramidal syndrome.

Polypharmacy in three different spontaneous adverse drug event databases.

OBJECTIVE: Polypharmacy has become a major problem in medical care worldwide, including in Japan. The purpose of this study was to investigate the current situation of polypharmacy using different spontaneous adverse drug event report databases. MATERIALS AND METHODS: A retrospective data analysis was performed using reports from 2007 to 2015 from three different spontaneous adverse drug event report databases: the Japanese Adverse Drug Event Report (JADER) constructed by the Pharmaceuticals and Medical Devices Agency in Japan, the US Food and Drug Administration (FDA) Adverse Drug Event Reporting System (FAERS) constructed by the FDA in the United States, and the Canada Vigilance Adverse Reaction Online Database (CVARD) constructed by the government of Canada. Polypharmacy trends during the study period were investigated. RESULTS: The mean numbers of drugs per report in the JADER, FAERS, and CVARD databases during the study period were 6.62, 3.76, and 3.44, respectively. The mean number of drugs per report increased with age in all three databases, with a peak at ages 70 - 79 years in all three databases (7.0 drugs for JADER, 4.7 drugs for FAERS, and 4.2 drugs for CVARD). CONCLUSION: Adverse event reports were more likely to develop in the patients treated through polypharmacy. Polypharmacy in Japan should be improved to prevent adverse events. Additionally, the patients aged ≥ 80 years tended to develop adverse events even if the number of prescribed drugs was relatively small. Therefore, polypharmacy should be noted in these patients to prevent adverse events.

Polypharmacy in elderly patients in Japan: Analysis of Japanese real-world databases.

WHAT IS KNOWN AND OBJECTIVE: Polypharmacy is associated with an increased risk of adverse drug reactions (ADRs) and drug interactions, decreased adherence to medication and increased medical cost. Recently, polypharmacy has become a major problem in medical care in Japan as a result of the increase in the ageing population. The purpose of this study was to investigate the current situation of polypharmacy and the association between polypharmacy and adverse events. METHODS: A retrospective data analysis was performed using two different real-world data from 2007 to 2015 in Japan. The Japanese Adverse Drug Event Report (JADER), a public spontaneous adverse drug reaction database constructed by the Pharmaceuticals and Medical Devices Agency (PMDA), and a large prescription database constructed by a database vendor (Japan Medical Information Research Institute, Inc Japan [JMIRI]) were analysed. Trends of polypharmacy during the study period were investigated. RESULTS AND DISCUSSION: The mean number of drugs per report in the JADER database and per prescription in the JMIRI databases during the study period ranged from 4.8 to 5.6 and 3.5 to 3.7, respectively. The mean number of drugs increased with age in both the JADER and JMIRI databases, and the peak of the mean number of drugs was at 80-89 years (5.74 drugs) in the JADER database and at 90-99 years (4.97 drugs) in the JMIRI database. WHAT IS NEW AND CONCLUSIONS: The number of drugs increased until age 90 years or more, even though adverse events are more likely to occur after the age of 80 in Japan. Therefore, polypharmacy in the elderly should be focused on the patients aged ≥80 years rather than patients aged ≥65 years from the viewpoint of the prevention of adverse events.