ED Medications: How They Work
Erectile Dysfunction medicine works by increasing blood flow to the penis. The most common medications are sildenafil (Viagra), tadalafil (Cialis), and vardenafil (Levitra). These drugs are called phosphodiesterase type 5 inhibitors of PDE5 inhibitors. They block the action of an enzyme called PDE5, which breaks down a chemical in the body called cGMP. cGMP causes the blood vessels in the penis to widen, allowing more blood to flow in. How the Medications Work When aroused, the body releases nitric oxide, which helps relax penile muscles and blood vessels. This allows blood to flow into the penis, causing an erection. PDE5 inhibitors enhance this effect by blocking the PDE5 enzyme that breaks down cGMP. For the medication to work, sexual stimulation is still needed. The drugs won't cause an erection without arousal. The effects of each medication can last from 4 to 36 hours depending on the dose. This means you have to time when you take the pill. For example, sildenafil and varden