Evaluation of two Japanese regulatory actions using medical information databases: a 'Dear Doctor' letter to restrict oseltamivir use in teenagers, and label change caution against co-administration of omeprazole with clopidogrel

• Published in: Journal of clinical pharmacy and therapeutics Vol. 39; no. 4; pp. 361 - 367
• Main Authors: Hanatani, T., Sai, K., Tohkin, M., Segawa, K., Antoku, Y., Nakashima, N., Yokoi, H., Ohe, K., Kimura, M., Hori, K., Kawakami, J., Saito, Y.
• Format: Journal Article
• Language: English
• Published: Oxford Blackwell Publishing Ltd 01.08.2014; Blackwell; Hindawi Limited
• Subjects: Adolescent; Age Factors; Antiviral Agents - administration & dosage; Antiviral Agents - therapeutic use; Biological and medical sciences; Child; clopidogrel; Databases, Factual - statistics & numerical data; Drug and Narcotic Control; Drug Interactions; General pharmacology; Humans; Interrupted Time Series Analysis; Japan; medical information database; Medical sciences; Miscellaneous; omeprazole; Omeprazole - administration & dosage; Omeprazole - therapeutic use; oseltamivir; Oseltamivir - administration & dosage; Oseltamivir - therapeutic use; Pharmacology. Drug treatments; Pharmacovigilance; Platelet Aggregation Inhibitors - administration & dosage; Platelet Aggregation Inhibitors - therapeutic use; Practice Patterns, Physicians' - statistics & numerical data; Proton Pump Inhibitors - administration & dosage; Proton Pump Inhibitors - therapeutic use; Regression Analysis; regulatory action; Ticlopidine - administration & dosage; Ticlopidine - analogs & derivatives; Ticlopidine - therapeutic use; Young Adult; Asia; Japan; Neuraminidase inhibitor; H; Antiulcer agent; K; Information; medical information database; Proton pump inhibitor; Therapeutic information; Antisecretory agent; Antithrombotic agent; Database; Antiviral; Drug interaction; Human; Evaluation; Enzyme; Use; Enzyme inhibitor; Pharmacovigilance; Antiplatelet agent; Glycosylases; Omeprazole; Oseltamivir; Benzimidazole derivatives; Exo-α-sialidase; Glycosidases; Adolescent; exchanging ATPase; Hydrolases; Clopidogrel; Regulation; regulatory action; Thienopyridine derivative; clopidogrel; omeprazole; oseltamivir; pharmacovigilance
• ISSN: 0269-4727; 1365-2710
• DOI: 10.1111/jcpt.12153

Summary What is known and objective The implementation of appropriate epidemiological methodology using medical information databases (MIDs) to evaluate the effects of regulatory actions has been highly anticipated. To assess scientific methods for active pharmacovigilance using MIDs, we conducted a quantitative assessment of the impact of two regulatory actions by the Japanese government: (i) restriction of use of oseltamivir in teenagers in March 2007 and (ii) caution against the co‐administration of omeprazole (OPZ) with clopidogrel (CPG) in April 2010. Methods Data were obtained from four hub hospitals in Japan. We measured the seasonal proportion of patients prescribed oseltamivir to those prescribed neuraminidase inhibitors for the 2002/2003 to 2010/2011 seasons. The monthly proportion of patients co‐administered OPZ and CPG (OPZ+CPG) to those prescribed CPG was measured from May 2009 to April 2011. We evaluated the changes observed with implementation of the regulatory actions. To estimate the impact of the actions, we conducted segmented regression analysis using interrupted time series data. The impact was assessed by two parameter estimates of the regression model: the change in level for short‐term effects and change in trend for long‐term effects. Results and discussion The use of oseltamivir in the target 10–19 years age group showed a significant and large decline (63·16%) immediately after the intervention (P = 0·0008). No change was observed in OPZ+CPG, although there was a relative inhibitory trend for OPZ+CPG compared with co‐administration of lansoprazole or rabeprazole with CPG as the control group. When restricted to new users of CPG, the stratified results were consistent with the overall results. What is new and conclusion The current analysis demonstrates the effectiveness of two regulatory actions. The results of the current study indicate that MID research can contribute to assessing and improving pharmacovigilance activities. Impacts of two regulatory actions on drug safety in Japan were evaluated using hospital medical information databases (MIDs). The segmented regression analysis using interrupted time series data revealed the effectiveness of these actions. The current study supports the benefit of MID research for improving pharmacovigilance.