INVESTIGATION INTO THE DURATION OF ACTION OF SUSTAINED-RELEASE IBUPROFEN IN OSTEOARTHRITIS AND RHEUMATOID-ARTHRITIS

The duration of action of sustained-release ibuprofen ('Brufen Retard' ) was investigated in a 14-day double-blind study involving 14 osteoar thritis and 10 rheumatoid arthritis patients. The recommended once-dai ly dosage of this preparation (1600 mg taken in the evening)provided e ffective control of arthritic symptoms for both patient groups, with s ignificant overall improvements in pain and stiffness compared to base line. Substitution of placebo for a single dose of the active treatmen t resulted in a trend towards worsening of pain and stiffness in the r heumatoid group; however, the only statistically significant change in volved impaired quality of sleep (p = 0.03) du ring the night after pl acebo administration, over 24-hours after the previous dose of active medication. In this particular study, symptom control was also clearly achieved for the osteoarthritis patients, as this group showed no det erioration within the same period The 24-hour clinical action underlyi ng these findings is consistent with ibuprofen plasma profiles obtaine d with the sustained-release preparation in earlier pharmacokinetic st udies. It is likely that the greater sensitivity of rheumatoid patient s to withdrawal of a single day's active treatment in this study refle cts a more severe inflammatory disease process than that of the osteoa rthritis patients.