Review of pharmacological data on benzydamine.

Pharmacological results are reviewed supporting the use of benzydamine in so-called "primary inflammations" rather than in rheumatic diseases. In experimental studies, benzydamine shares with aspirin-like drugs their activity in acute inflammatory responses but not in Freund's adjuvant arthritis. The efficacy of benzydamine is mainly manifested against phenomena such as pain and oedema which depend on local mechanisms in the inflammatory focus. Other manifestations such as hyperthermia which are indicative of systemic functional involvement, are poorly affected by the drug. Benzydamine also lacks some of the typical side-effects of aspirin-like drugs which are thought to reflect their generalized activity. Finally topical application increases the analgesic and antiinflammatory activities of benzydamine much more than those of other antiinflammatory drugs. The data reported demonstrate that benzydamine specifically acts on the local mechanisms of inflammation. In order to explain this feature the chemical, pharmacokinetic and biochemical properties of benzydamine are discussed.