Non-steroidal anti-inflammatory drug and antacid co-prescription in Taiwan: analysis of national insurance claims.

Background: Antacids were usually co-prescribed with non-steroidal anti-inflammatory drugs (NSAIDs), although no broad evidences were available as to the effects of antacids in preventing NSAID-associated gastropathy. We performed a survey of national insurance claims for outpatient services in Taiwan to determine the extent of this co-therapy nationwide.

Methods: The National Health Insurance Research Database supplied the sampling datasets for analysis. They represented 0.2% of the entire claims for outpatient medical services in 1999. Co-prescribing was assessed as NSAIDs and antacids on the same prescription. The selection and grouping of NSAIDs followed the guidelines of the Anatomical Therapeutic Chemical (ATC) Classification System recommended by the World Health Organization. Only the oral drugs prescribed on regular visits were taken into account.

Results: In totally 425,442 prescriptions with 1,825,604 items of drugs, non-aspirin NSAIDs were present in 108,818 (25.6%) prescriptions and antacids in 235,252 (55.3%) prescriptions respectively. Furthermore, antacids were present in 71.3% of prescriptions that contained NSAIDs and in 49.8% of prescriptions that did not contain NSAIDs (p < 0.001). Significant association of NSAIDs and antacids existed in different specialties of prescribing physicians, but the co-prescription rate (antacids in NSAIDs prescriptions) varied from the highest of 92.8% in the neurosurgery to the lowest of 49.8% in the pediatrics. Significant association of NSAIDs and antacids also existed at different levels of health care facilities, where the co-prescription rates were 80.9% at medical centers, 83.5% at regional hospitals, 87.4% at local hospitals, and 66.6% at primary care units. The subgroup of oxicams was more frequently co-prescribed with antacids than other subgroups (odds ratio = 1.51, p = 0.001).

Conclusions: Concomitant prescription of oral non-aspirin NSAIDs and antacids was indeed a popular practice in Taiwan. Beside their effects in alleviating the NSAID-associated dyspepsia, the role of antacids in preventing NSAID-associated peptic ulcers or in masking the warning symptoms of these ulcers demands further evaluation.