Transsynovial kinetics of piroxicam in patients with rheumatoid arthritis.

Twenty-four patients suffering from rheumatoid arthritis, who required articular puncture, participated in this open label study. Following a washout period of 7 days piroxicam 20 mg was administered once daily for 7 days. The average drug concentration in a dose interval in plasma fluctuated between 4.45 micrograms/ml and 8.02 micrograms/ml, and in synovial fluid it ranged between 4.16 micrograms/ml and 5.55 micrograms/ml. Piroxicam was eliminated from plasma with a half-life of 41.7 h and 43.2 h from synovial fluid as calculated from measured and interpolated data from all patients. Despite the short treatment period, clinical improvement could clearly be demonstrated.