Potential drug interactions in patients with rheumatoid arthritis.

Introduction: The term polypharmacy, meaning the concomitant use of multiple medications by one individual, has been widely reported in institutionalized or elderly patients. It can, however, occur in patients with chronic diseases, such as rheumatoid arthritis (RA).

Objective: To quantify polypharmacy in a group of RA patients and to assess the risk of potential undesirable interactions between medications used for managing RA and those used for non-chronic diseases.