Vardenafil is a phosphodiesterase‑5 (PDE5) inhibitor used for erectile dysfunction, enhancing nitric oxide cGMP signaling to relax corpus cavernosum smooth muscle and improve penile blood flow during sexual stimulation; it does not increase libido and requires arousal to work. Compared with similar agents, it has a relatively quick onset and is available as standard tablets and orally disintegrating forms. Key clinical guidance emphasizes cardiovascular assessment, avoidance with nitrates or significant QT prolonging risks, and individualized counseling on timing relative to sexual activity, food, and alcohol for consistent performance and suitability in comorbid conditions.