The analgetic properties of piroxicam in animals and correlation with experimentally determined plasma levels.

In animal antinociceptive tests responsive to non-steroidal anti-inflammatory drugs (NSAID), piroxicam is an extremely potent and effective analgetic at doses of 1--2 mg/kg p.o. In mice the plasma half-life and duration of analgetic action is short (t 1/2 = 1.7 h), unlike man, wherein piroxicam exhibits an exceptionally long duration of action (half-life 40--45 h). An excellent correlation is observed between plasma levels and analgetic activity in the writhing test in mice suggesting that piroxicam will exhibit potent and long-lasting analgetic activity in man.