Concentrations of flurbiprofen in serum and synovial fluid from patients with active rheumatoid disease: some preliminary observations.

In 3 patients with active rheumatoid disease, concentrations of flurbiprofen of approximately 2 microgram per ml were achieved in synovial fluid 3 hours after a single oral dose of flurbiprofen (100 mg). The highest concentrations were seen between 3 and 9 hours after administration of the dose. The concentration of flurbiprofen in synovial fluid seemed to fall more slowly than in the circulation, but more extensive data would be needed to confirm this. In all 3 patients the drug was absorbed rapidly into the circulation, the highest serum concentrations of 7 microgram to 9 microgram per ml being seen in the first blood sample withdrawn 1.5 hours after administration of the dose. Serum concentrations fell with a mean apparent half-life of approximately 3 hours.