Analgesic activity of cyclic imides: 1,8-naphthalimide and 1,4,5,8-naphthalenediimide derivatives.

In early studies, we have reported the synthesis and biological activities of several cyclic imides. The present study describes the analgesic activity of 1,8-naphthalimide and 1,4,5,8-naphthalenediimide derivatives in a standard murine model of analgesia. The pharmacological results show that all compounds studied, given intraperitoneally, produced significant inhibition of acetic acid-induced abdominal constrictions. At the ID50 (micromol/kg) level, these cyclic imide derivatives were about 40-270-fold more potent in this assay than aspirin and acetaminophen, two well-known and widely used analgesics. These results extend previous studies on the analgesic activity of cyclic imides.