Abstract
BACKGROUND: Rebamipide has been widely co-prescribed with non-steroidal anti-inflammatory drugs (NSAIDs) in Japan for decades. This study aimed to evaluate the effectiveness of rebamipide in preventing upper gastrointestinal bleeding in new users of NSAIDs without risk factors of NSAID-induced ulcers other than age. METHODS: A nested case-control study was conducted using medical claims data of 1.66 million inhabitants of 17 municipalities participating in Japan's Longevity Improvement & Fair Evidence study. The cohort entry (t0) corresponded to a new user of NSAIDs for osteoarthritis or low back pain. Patients with risk factors of NSAID-induced ulcers other than age were excluded. Cases were defined as patients who underwent gastroscopy for upper gastrointestinal bleeding (occurrence date was defined as index date). A maximum of 10 controls were selected from non-cases at the index date of each case by matching sex, age, follow-up time, and type and dosage of NSAIDs. Exposure to rebamipide was defined as prescription status from t0 to index date: Non-user (rebamipide was not co-prescribed during the follow-up period), Continuous-user (rebamipide was co-prescribed from t0 with the same number of tablets as NSAIDs), and Irregular-user (neither Non-user nor Continuous-user). Conditional logistic regression analysis was conducted to estimate each category's odds ratio compared to non-users. FINDINGS: Of 67,561 individuals who met the inclusion criteria, 215 cases and 1,516 controls were selected. Compared with that of Non-users, the odds ratios and 95% confidence interval were 0.65 (0.44-0.96) for Continuous-users and 2.57 (1.73-3.81) for Irregular-users. CONCLUSIONS: Continuous co-prescription of rebamipide significantly reduced the risk of upper gastrointestinal bleeding in an Asian cohort of new users of NSAIDs with osteoarthritis or low back pain without risk factors other than age.