ANTINOCICEPTIVE ACTIVITY OF FILENADOL ON INFLAMMATORY PAIN

The novel analgesic filenadol ,4'-methylenedioxyphenyl)-1-morpholinopr opan-2-ol) inhibited phenyl-p-benzoquinone-induced writhing in mice wi th ID50 values of 68.8 (p.o.), 1.67 (i.v.) and 0.48 (i.c.v.) mg/kg. Hy peralgesia induced by arachidonic acid, PGE(2) or LTB(4) in this test was also decreased by filenadol (ID50 = 24.4, 3.7 and 50.1 mg/kg p.o., respectively). This compound was effective on PGE(2), LTB(4), bradyki nin, PAF or IL-1 beta-induced decrease in pain threshold in the rat pa w pressure model and almost totally suppressed the writhing induced by zymosan in mice, while peritoneal production of 6-ketoPGF(1 alpha), w as inhibited by 48.5-62 % and only at 100 mg/kg significant inhibition of LTC(4) was achieved. The late phase of formalin-induced pain respo nse in mice was prevented by filenadol, without affecting the oedema. Filenadol is an antinociceptive agent that reduces the hyperalgesic ef fects of inflammatory mediators besides inhibiting partially the synth esis of eicosanoids.