If you ever need emergency medical treatment for a heart problem, the health care providers who treat you will need to know when you last took tadalafil. Tadalafil is also used to treat men who have signs and symptoms of benign prostatic hyperplasia BPH. Tadalafil Adcirca is used to improve the ability to exercise in people with pulmonary arterial hypertension PAH; high blood pressure in the vessels carrying blood to the lungs, causing shortness of breath, dizziness, and tiredness. When the smaller blood vessels in the lungs become more resistant to blood flow, the right ventricle must work harder to pump enough blood through the lungs. Children—Use and dose must be determined by your doctor. Tadalafil has been extensively studied for ED. This leads to shortness of breath when exercising or completing regular daily activities.Cialis may be used as needed to treat ED. For this use, doses range from 5 milligrams (mg) to 20 mg as needed before sexual activity. Cialis may keep working for up to 36 hours after taking a dose. For this reason, you may not need to take this medication every day when using it for occasional use.  · Descriptions Tadalafil is used to treat men who have erectile dysfunction (also called sexual impotence). Tadalafil belongs to a group of medicines called phosphodiesterase 5 (PDE5) inhibitors. These medicines prevent an enzyme called phosphodiesterase type-5 from working too quickly. The penis is one of the areas where . Cialis is not for use in women. Tadalafil is not approved for use by anyone younger than 18 years old. Tadalafil pregnancy and breastfeeding warnings (more detail) Related/similar drugs tamsulosin, finasteride, sildenafil, Flomax, Cialis, prazosin, doxazosin. Tadalafil 20 mg (T20) View all images.