Fosfodiesteraasi5estäjiä

Fosfodiesteraasi5estäjiä, commonly known as PDE5 inhibitors, are a class of medications primarily used to treat erectile dysfunction and, in some cases, pulmonary arterial hypertension. These drugs work by blocking the action of an enzyme called phosphodiesterase type 5 (PDE5). PDE5 is responsible for breaking down cyclic guanosine monophosphate (cGMP). In the context of erectile function, increased levels of cGMP lead to smooth muscle relaxation in the corpus cavernosum of the penis, allowing for increased blood flow and an erection. By inhibiting PDE5, these medications prolong the presence of cGMP, thereby facilitating and maintaining an erection.

The first PDE5 inhibitor, sildenafil, was approved in 1998. Other well-known PDE5 inhibitors include tadalafil, vardenafil, and avanafil. While their primary mechanism of action is the same, they differ in their onset of action, duration of effect, and potential side effects. Common side effects can include headache, flushing, nasal congestion, and visual disturbances. PDE5 inhibitors are generally not recommended for individuals taking nitrate medications due to the risk of a dangerous drop in blood pressure. They are a significant advancement in the treatment of conditions related to impaired smooth muscle relaxation.