Synovial-fluid pharmacokinetics of ketoprofen.

A study was made of the plasma and synovial-fluid levels of ketoprofen after single oral doses of 50 mg and 100 mg given to patients with rheumatoid arthritis. The drug was rapidly absorbed and plasma levels were similar to those seen in healthy volunteers. The mean early plasma half-life of ketoprofen in both volunteers and patients with rheumatoid arthritis was 1.5 to 2 hours. A cumulative effect of ketoprofen was evident in the synovial-fluid of the patients studied.