[Effects of benzydamine on leukocyte aggregation]

The effect of benzydamine (Tantum) on the aggregation of rat leukocytes was compared to some commonly used nonsteroidal antiinflammatory drugs (NSAID). The aggregation response was induced by various activators such as the tumour promoter phorbol myristate acetate, the chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine (FMLP), arachidonic acid, sodium arachidonate, platelet activating factor (PAF) and a combination of cytochalasin B and Ca++-ionophore A 23187. As compared to indomethacin, piroxicam and acetylsalicylic acid benzydamine was inhibitory against most of the activators, i.e. the receptor-mediated induction of the aggregation by FMLP, the phorbol ester and sodium arachidonate. No effect could be observed against PAF induced aggregation. Under the assay conditions benzydamine exerted cytolytic effects at 2 X 10(-4) mol/l. Cytolysis reached 100% at 5 X 10(-4) mol/l benzydamine, as could be shown microscopically and by measurement of free cytosolic lactate dehydrogenase. Thus benzydamine exerted a broad spectrum inhibitory activity against rat leukocyte aggregation, possibly explained by its unspecific membrane affinity.