What Pirfenidone does

Pirfenidone's (Pirfenidone's) exact mechanism of action is not fully understood. It is thought that the antioxidant effects of pirfenidone contribute to its anti-inflammatory effects, resulting in anti-fibrotic effects. Pirfenidone reduces the production of transforming growth factor-β1 (TGF-β1), a key profibrotic and proinflammatory cytokine associated with idiopathic pulmonary fibrosis (IPF). By inhibiting TGF-β1, pirfenidone inhibits TGF-β1-induced differentiation of human lung fibroblasts into myofibroblasts, thereby preventing excessive collagen synthesis and extracellular matrix production. In animal models, pirfenidone inhibits the influx of inflammatory cells and improves bleomycin-induced pulmonary vascular permeability.