The production and action of primary proinflammatory cytokines are strictly controlled by a series of circuits to avoid damage that they can cause if produced in excess. Interleukin-10 and interleukin-1 receptor antagonist contribute to the control of the magnitude of the inflammatory responses in vivo. Benzydamine, a non-steroidal anti-inflammatory drug that has been shown to have suppressive activity for the proinflammatory cytokines, tumor necrosis factor-alpha and interleukin-1beta, was investigated for its effects on interleukin-10 and interleukin-1ra production. The drug did not modify the production of interleukin-10 and interleukin-1ra by peripheral blood mononuclear cells stimulated with lipopolysaccharide, under conditions where tumor necrosis factor-alpha and interleukin-1beta were decreased. The antiinflammatory capacity of benzydamine might thus result from its ability to reduce the production of proinflammatory cytokines, without affecting antiinflammatory factors.