Sildenafil is a phosphodiesterase (PDE) -5 inhibitor used in erectile dysfunction treatment and as a vasodilator in the treatment of pulmonary arterial hypertension.
In cases of erectile dysfunction, it increases the local action of nitric oxide favoring erectile response by increasing the blood flow to the penis during sexual stimulation. Sexual stimulation is necessary for its action; it does not increase the frequency nor the intensity of sexual desire. Neither does it prevent pregnancy nor protect against sexually transmitted diseases such as human immunodeficiency virus (HIV). Currently, phosphodiesterase-5 inhibitors constitute the first pharmacologic step in light-moderate erectile dysfunction.
Sildenafil (Revatio®) is used to improve the ability to exercise in those adults who suffer from pulmonary arterial hypertension (high blood pressure in the vessels that carry blood to the lungs, causing shortness of breath, dizziness and tiredness).
Sildenafil should not be used to treat children.
Sildenafil can cause side effects, usually dose dependant:
- Very frequent (>10%): headache, sensation of suffocating, flushing, dyspepsia, back pain, diarrhea, limb pain, fever. Also transitory visual disorders (2-11%) may consist of an abnormal perception of colors, increased light perception, blurry vision, red eye. Alopecia.
- Less frequent: dizziness, hives, nasal congestion, muscular pain, priapism, tonic-clonic seizures, severe hypotension (if taken concurrently with nitrates and nicorandil. Gynecomastia.
Gene or region studied