Drug utilization patterns of flupirtine following implementation of risk minimization measures in Germany.

This report characterizes flupirtine prescribing patterns before and after the implementation of risk minimization measures (RMM) in Germany as a complementary analysis to support previous study findings. A retrospective analysis was conducted using a patient-level longitudinal prescription database (IMS LRx) in Germany. The study population included patients who were prescribed flupirtine-containing products. One-year periods before (2012) and after (April 2015-March 2016) RMM implementation were assessed for the following measures: flupirtine use of up to two weeks, flupirtine use when other analgesics are contraindicated and concomitant use of drugs with a known potential to induce liver injury. The number of flupirtine users decreased by 41.0% from 248,738 patients in the pre-RMM implementation period to 146,764 in the post-implementation period. The proportion of patients prescribed flupirtine for up to 14 days increased significantly by 22.7%, from 67.9% to 90.6% in the pre- to post-implementation periods, respectively. Over half the patients received long-term medications for conditions contraindicated with the use of other analgesics within 12 months prior to the first flupirtine prescription in the pre- and post-implementation periods (57.1% and 52.3%, respectively). Concomitant prescriptions of drugs with known potential hepatotoxic effects were recorded in 36.6% and 34.2% of flupirtine prescriptions during the pre- and post-implementation periods, respectively. While physicians generally restricted flupirtine prescriptions to the short-term treatment duration recommended in the labeling, the other labeling recommendations were not as stringently adopted. Findings of this investigation support a previous study conducted in an electronic medical record database.