Possible disease-modifying effects of naproxen in the adjuvant-arthritic rat.

Naproxen was evaluated for possible disease modifying effects in the Freund's adjuvant injected rat (AIR). Oral administration of the clinical dose, 7 mg/kg/day, lead to an almost complete inhibition of hindpaw swelling and cartilage and bone erosion. This was noted in animals maintained on drug as well as those in which therapy was discontinued. AIR, comparable to arthritic patients, demonstrate a reduced lymphocytic response to T cell mitogens. This response was normalized in naproxen-treated rats. These results suggest that naproxen has a disease modifying effect in the AIR.