14
Jan
Introduction Erectile dysfunction (ED) is the inability to get or keep an erection firm enough for satisfactory sexual activity. It can be caused by physical or psychological factors. Phosphodiesterase type 5 inhibitors (PDE5 inhibitors) are the most common oral treatments for ED. They work by blocking the enzyme PDE5 to improve blood flow to the penis and allow an erection to occur. This article compares two of the most well-known PDE5 inhibitor medications - sildenafil (Viagra) and tadalafil (Cialis). Sildenafil was introduced in 1998 as the first oral treatment for ED. Tadalafil entered the market in 2003 as a longer-lasting…