Concomitant use of gastroprotective drugs among elderly NSAID/COX-2 selective inhibitor users: a nationwide register-based study

BACKGROUND AND OBJECTIVES: NSAIDs and cyclo-oxgenase (COX)-2-selective inhibitors have been associated with gastrointestinal (GI) complications among the elderly. It is recommended that gastroprotective drugs (i.e. misoprostol, proton pump inhibitors or high doses of histamine H2 receptor antagonists) be taken concomitantly to prevent NSAID-induced GI complications among older people. However, there are concerns that the rate of concomitant use of gastroprotective drugs in elderly NSAID users is too low. This study aimed to investigate the extent to which elderly users of NSAIDs/COX-2-selective inhibitors are concurrently taking gastroprotective drugs, and to determine the factors associated with concomitant use of gastroprotective drugs and NSAIDs/COX-2-selective inhibitors in a nationwide population of older people. METHODS: We analysed data on age, sex and dispensed drugs for people>or=75 years of age registered in the Swedish Prescribed Drug Register from October to December 2005 (n=732,230) and located 41,626 NSAID/COX-2-selective inhibitor users. Logistic regression analysis was used for analysing the association between the use of different NSAIDs/COX-2-selective inhibitors and gastroprotective drugs, and between individual characteristics and use of gastroprotective drugs. RESULTS: Gastroprotective drugs were used by 22% of NSAID/COX-2-selective inhibitor users. Celecoxib, ketoprofen, meloxicam and etoricoxib were most commonly used concomitantly with gastroprotective drugs. Meloxicam and celecoxib were most strongly associated with gastroprotective drugs, after adjustment for age, sex and number of other drugs. Furthermore, NSAID/COX-2-selective inhibitor+oral corticosteroid users, NSAID/COX-2-selective inhibitor+selective serotonin reuptake inhibitor users and users of two or more NSAIDs/COX-2-selective inhibitors were more likely to concomitantly use gastroprotective drugs compared with NSAID/COX-2-selective inhibitor only users, after adjustment for age, sex and number of other drugs. However, users of NSAIDs/COX-2-selective inhibitors+anticoagulants (both warfarin and low-dose aspirin [acetylsalicylic acid]) did not show an increased likelihood of concomitant use of gastroprotective drugs, after adjustment for age, sex and number of other drugs. CONCLUSION: Our results indicate that gastroprotective drugs are not prescribed to elderly NSAID users according to guidelines. Furthermore, COX-2-selective inhibitors were used with gastroprotective drugs more often than were traditional NSAIDs. Greater awareness of factors contributing to NSAID/COX-2-selective inhibitor-induced GI complications is warranted, particularly with respect to advanced age and concurrent use of anticoagulants.