The clinical relevance of piroxicam-beta-cyclodextrin (PBC) in the long-term treatment of osteoarthritis and rheumatoid arthritis is reviewed. Two hundred and twenty-five patients--one hundred with rheumatoid arthritis and one hundred and twenty five with osteoarthritis--were enrolled in a double-blind, randomised, controlled study versus piroxicam. Drugs were administered once-daily, for twelve weeks. The indices of efficacy (pain intensity, severity of inflammation, functional impairment evaluated at 0,2,4,8 and 12 weeks showed the good analgesic effect of piroxicam without significant differences between its two formulations. Tolerance appeared to be better in the group of patients treated with PBC than in the one treated with piroxicam. Both the incidence and severity of side effects were lower for patients treated with PBC. The majority of side effects were related to the gastrointestinal tract. The study suggests that PBC, used in the long term treatment of rheumatic diseases, improves the safety of piroxicam without affecting its efficacy. In another study, thirty patients with chronic osteoarthritis were randomly assigned to receive PBC or tenoxicam daily for eight weeks. Both drugs effectively reduced pain, inflammation, and functional limitation of the affected joints. Endoscopy revealed minor post-treatment mucosal lesions; these tended to be less severe with PBC than with tenoxicam. The clinical experience in the long-term treatment of rheumatic conditions indicates that the microencapsulation of piroxicam as piroxicam-beta-cyclodextrin has provided a new drug with a superior tolerability compared to the parent compound without affecting its high efficacy on the symptoms of the primary disease.