Benzydamine

Despite being categorized as a non-steroidal anti-inflammatory drug (NSAID), benzydamine demonstrates various mechanisms of action that differ from those of traditional aspirin-like NSAIDs. In particular, benzydamine predominantly acts by inhibiting the synthesis of pro inflammatory cytokines like tumour necrosis factor-alpha (TNF-α) and interleukin-1β (IL-1β) without largely affecting other pro inflammatory cytokines (ie. such as IL-6 and IL-8) or anti-inflammatory cytokines (ie. like IL-10 or IL-1 receptor antagonist).

Moreover, benzydamine is largely a weak inhibitor of prostaglandin synthesis as it has been shown to effectively inhibit cyclooxygenase (COX) and lipoxygenase enzyme activity only at concentrations of 1mM or greater. Considering most contemporary usages of benzydamine are topical applications that are generally not well absorbed through the skin and/or non-specialized mucosae, benzydamine does not often achieve the kind of absorption or blood concentrations necessary to cause any extraneous distant systemic effects or COX inhibition, allowing it to localize its action.

Additionally, it is also hypothesized that benzydamine is capable of inhibiting the oxidative burst of neutrophils and membrane stabilization. These actions are exhibited by the substance’s ability to inhibit the release of granules from neutrophils and to stabilize lysosomes.

Furthermore, benzydamine is capable of a local anaesthetic effect that may be related to its capability for inhibiting the release of inflammatory mediators like substance P and calcitonin gene related peptide from sensory nerve endings. Since substance P is capable of causing the release of histamine from mast cells, benzydamine’s prevention of substance P release further contributes to an anti-inflammatory effect.

Benzydamine also demonstrates a non-specific antibacterial activity against various bacterial strains that are resistant to broad-spectrum antibiotics such as ampicillin, chloramphenicol, and tetracycline at concentrations of about 3 mmol/L. Combinatorial use of benzydamine and other antibiotics like tetracycline and chloramphenicol are also synergistic against antibiotic resistant strains of Staphylococcus aureus and Pseudomonas aeruginosa.