Objective: To examine the extent prescribed nonsteroidal anti-inflammatory drugs (NSAIDs) are used by elderly people in Alberta as well as the degree of concurrent use of multiple NSAIDs, of peptic ulcer medications and of certain medications known to have clinically significant adverse interactions with NSAIDs.
Design: Retrospective analysis of the Alberta Blue Cross database.
Setting: Alberta.
Patients: All people 65 years of age and older using the subsidized drug benefit plan for whom prescription claims were submitted for reimbursement between Jan. 1 and June 30, 1991.
Outcome measures: Number of people who received one or more prescriptions for NSAIDs, rates of prescribing peptic ulcer medications and drugs with the potential for clinically significant interactions with NSAIDs among NSAID users and non-NSAID users, and rate of prescribing more than one NSAID concurrently.
Results: Of the Albertan population 65 years of age and over 61,601 (26.7%) received at least one prescription for an NSAID during the study period. In decreasing order, the five most commonly prescribed NSAIDs were acetylsalicylic acid, diclofenac, naproxen, indomethacin and ibuprofen. The total cost of NSAID therapy was $5,415,974. Of the people prescribed an NSAID 25.8% were also prescribed a peptic ulcer medication, as compared with 10.5% of the non-NSAID users. There was a significant relation between the increasing number of NSAID prescriptions and the likelihood of receiving a peptic ulcer medication. Those who received a prescription for an NSAID were more likely than non-NSAID users to have been prescribed coumarin anticoagulants, diuretics, angiotensin-converting-enzyme inhibitors, beta-blockers, oral corticosteroids, methotrexate and lithium, all of which are known to have possible adverse interactions with NSAIDs. A total of 2,631 people had two or more prescriptions for NSAIDs filled on the same day.
Conclusions: NSAIDs are prescribed frequently for elderly people and are associated with an increased likelihood of concurrent prescription of peptic ulcer medication and medications that could have adverse drug interactions with NSAIDs. Additional study is required to evaluate the appropriateness of NSAID use in elderly patients, to determine the degree of actual patient consumption of these medications, to document the true prevalence of clinically significant drug interactions and to formulate educational strategies to reach physicians with this information.