[New pharmacologic and biochemical findings on the mechanism of action of the non-steroidal antiphlogistic, benzydamine. A synopsis].

Benzydamine (Tantum) is an indolic non-steroidal antiinflammatory drug (NSAID) for systemic use in acute traumatic lesions and locally as mouth gargle wash. Benzydamine is lipophilic at pH 7.2, has an affinity for membranes and shows membrane stabilizing properties with local anaesthetic effects. Contrary to other NSAID, benzydamine does not inhibit the cyclo- nor the lipoxygenase (10(-4) mol/l) and is also not ulcerogenic in the rat. Phospholipase A2 is slightly inhibited as well as the lysophosphatide-acyltransferase (greater than 10(-4) mol/l). Macrophage PGE2 synthesis is enhanced at 10(-4) mol/l. The production of reactive oxygen species by phagocytes is effectively inhibited (10(-5)-10(-4) mol/l). Phagocyte degranulation and aggregation are also inhibited (10(-4) mol/l). The strongest in vitro effect is the inhibition of leukocyte adhesion to vascular endothelium (3-4 X 10(-6) mol/l). Benzydamine is also antithrombotic in the rat (ED35 8.5 mg/kg p.o.) and reduces PAF (platelet activating factor)-induced mortality in the mouse (50 mg/kg p.o.; p less than 0.05). It is concluded that benzydamine is antiinflammatory by preventing vessel wall damage from activated, adhering and emigrating leukocytes i.e. being vasoprotective.