Sildenafil (Viagra)

Sildenafil is used to treat erectile dysfunction (ED) in men. It belongs to a group of medicines called phosphodiesterase 5 (PDE5) inhibitors, which prevent the enzyme PDE5 from acting too quickly. The penis is one of the areas where this enzyme works.

Erectile dysfunction occurs when the penis does not become firm or expand during sexual excitement, or when it is difficult to maintain an erection. Normally, sexual stimulation increases blood flow to the penis to produce an erection. Sildenafil helps maintain the erection by controlling the PDE5 enzyme. It does not cause an erection without physical stimulation, such as during sexual intercourse.

Sildenafil is also used to treat pulmonary arterial hypertension (PAH) in both men and women. PAH is a type of high blood pressure that affects the blood vessels between the heart and the lungs. Sildenafil works in the lungs to relax blood vessels, increasing blood flow and reducing the heart’s workload.