But don’t assume that you’re alone. Oral medicines for ED usually work well and cause few side effects. Psychological Causes of Erectile Dysfunction The brain plays a key role in triggering the series of physical events that cause an erection, starting with feelings of sexual excitement. The body takes longer to absorb it after a high-fat meal or alcohol. Penile implants are another option and involve surgically placing a device that allows the penis to achieve an erection. When oral medications might not be safe Check with your health care team before you take any medicine for erectile dysfunction. In other cases, medications or other direct treatments might be needed.Viagra (sildenafil) is a prescription drug that’s used to treat erectile dysfunction (ED). The drug comes as a tablet you’ll take by swallowing. It’s usually taken as needed about 1 hour. Sildenafil is best known as a treatment for ED, the inability to get or keep an erection. Sildenafil is meant to be taken before having sex, with the understanding that its effects last only a few. Sildenafil (Viagra) is used to treat erectile dysfunction (impotence; inability to get or keep an erection) in men. Sildenafil (Liqrev, Revatio) is used to improve the ability to exercise in adults (Liqrev, Revatio) and children 1 year of age and older (Revatio) with pulmonary arterial hypertension (PAH; high blood pressure in the vessels carrying blood to the .