Clinical evaluation of a new controlled-release formulation of naproxen in osteoarthritis and rheumatoid arthritis

SummaryA two-part multi-centre study was carried out to assess the efficacy and tolerability of a new controlled-release (CR) naproxen tablet in the treatment of osteoarthritis and rheumatoid arthritis. Patients already receiving naproxen on a regular basis were first enrolled in a 6-week randomized double-blind trial comparing the controlled-release tablet (750 mg or 1000 mg once-a-day) to the standard marketed tablet (375 mg or 500 mg twice-a-day). At the end of this phase, patients in both treatment groups were eligible to enter the long-term phase involving 28 weeks of open-label treatment with controlled-release naproxen at the previously established dose level (750 mg or 1000 mg once-a-day). A total of 404 patients entered the initial double-blind phase, 320 of whom continued into the open-label phase. Twenty-nine (14%) naproxen patients and 23 (11%) naproxen CR patients were withdrawn prematurely from the double-blind phase, 87 (27%) patients from the open-label phase. Parameters of efficacy and to...