Action of a new non-steroid antiinflammatory drug, nimesulide, on activation of the complement system: an in vitro study.

The complement system has a pivotal role in the antiinflammatory reaction. Furthermore it has been shown that the sequential activation of the complement system may be inhibited at various levels by pharmacological agents such as non-steroidal antiinflammatory drugs. Therefore the eventual anticomplementary action of Nimesulide was assessed in vitro in various experimental models. It was found that it blocks immunohaemolysis in vitro and has a direct effect on serum complement activity. Nimesulide blocks the activation of third complement and this explains why the drug is also inhibitory on the inulin-induced haemolytic reaction.