Generic Drugs List

The most common medications used to treat erectile dysfunction (ED) are Viagra, Cialis, Sildenafil, and Levitra. They belong to a class of drugs called phosphodiesterase 5 inhibitors (PDE5 inhibitors), which will be explained below.

Before comparing the medications, it is important to know how an erection is achieved and how the medications used to treat ED help men achieve and maintain erections sufficient for sexual activity.

An erection occurs when someone is stimulated by an erotic thought or sexual contact. The brain then commands nitric oxide be produced. That leads to a series of chemical reactions in the blood vessels of the penis that results in 6 times the blood flow getting trapped in the penis. An erection might last indefinitely if it weren’t for chemicals called phosphodiesterases. They work at reversing the process that keeps the penis erect.

Usually there is a balance between the chemicals that cause an erection and those that would return the penis to being flaccid. They pull in opposite directions with one dominating over the other in a perfect sequence that lets a man have an erection as long as it is needed. That balance makes sure the phosphodiesterases to do their job when they should, but no sooner.

ED medications interfere with the chemicals that allow blood to leave the penis. They push the balance in favor of an erection. Men with erectile dysfunction benefit from having the chemicals leading to the erection outweigh the actions of the phosphodiesterases that cause the penis to lose its firmness. That is exactly what the medications for erectile dysfunction do; they block, or inhibit, the phosphodiesterases (that’s why they are called phosphodiesterase inhibitors). Simply stated, erectile dysfunction medications let the forces that give a man an erection rule over those that would not.