Student Tohoku university graduate school of medicine, medical science, Medical Statistics, Japan
Background: Generic drugs (GEs) are drugs that have been shown to be therapeutically equivalent to the brand-name drugs (BNs). However, it was reported that some generic alendronate tablet formulations outside Japan differed in the occurrence of adverse effects in the upper gastrointestinal tract. In order to ensure the safe use of GEs, it is necessary to investigate the actual safety status of generic alendronate products in Japan in the real world.
Objectives: Using a real-world database, we compared the safety of GEs to the BNs of alendronate sold in Japan.
Methods: Data: Administrative claim data from January 2005 to December 2020 registered in the JMDC claims database contracted with health insurance associations nationwide Setting: Analysis of parson who were prescribed alendronate tablets Exposure: Exposure if first alendronate is GE, control if BN. Outcome: ① Upper Gastrointestinal Events: identified upper gastrointestinal-related diagnoses within 90 days from the day following the first prescription ② Prescription Discontinuation: discontinuation of bisphosphonate (BP) tablets within 90 days of the ①Upper Gastrointestinal Events Analysis population: Propensity score matching (1:1) was performed using background factors such as age, gender, history of upper gastrointestinal event, history of other diseases, history of prescription of drugs with bleeding risk, history of hospitalization, etc. The analysis calculated the difference in incidence proportion, and 95% confidence intervals for the following two events. (1) Upper gastrointestinal event between GE and BN (2) Discontinuation of prescription between GE and BN (3) Upper gastrointestinal event between the group containing hydroxypropylcellulose(HPC) (HPC group) and the group not containing HPC(non HPC) among the GE group
Results: Of the 11872 patients identified as first-time users of alendronate tablets, 5858 (49.3%) were in the GE group and 6014 (50.7%) were in the BN group. Of the GE group, 2600 (44.4%) were in the HPC group and 3258 (55.6%) were in the non HPC group. After matching between GE and BN groups, the population for analysis was 5197 each, and the results for (1) to (3) were (1) 1.57% (0.88%-2.27%), (2) 0.39% (0.06%-0.73%), and (3) -0.23% (-1.34%-0.87%), respectively.
Conclusions: Generic alendronate tablets may have safety concerns compared to the BN drug. Identification of this factor needs to be considered in the future.
