Tadalafil (Cialis)

[Product name]  Tadalafil (Cialis)

[ Molecular formula ]  C22H19N3O4

[ CAS NO.]  171596-29-5

[ Molecular weight ]  389.41

[ About Tadalafil ]   Tadalafil is a medicine used to treat erectile dysfunction in men. Erectile dysfunction is a condition where the penis does not harden and expand when a man is sexually excited, or when he cannot keep an erection. When a man is sexually stimulated, his body's normal response is to increase blood flow to his penis. This results in an erection. Tadalafil helps increase blood flow to the penis and may help men with erectile dysfunction get and keep an erection satisfactory for sexual activity. Once a man has completed sexual activity, blood flow to his penis decreases, and his erection goes away.This medicine is available only with your doctor's prescription.This product is available in the following dosage forms

[ Drug Class and Mechanism ]   Tadalafil is an oral drug that is used for treating impotence (the inability to attain or maintain a penile erection). It is in a class of drugs called phosphodiesterase inhibitors.

[ Pharmacokinetics ]    Erection of the penis is caused by the filling of the penis with blood. Filling occurs because the blood vessels that bring blood to the penis increase in size and deliver more blood to the penis, and, at the same time, the blood vessels that take blood away from the penis decrease in size and remove less blood from the penis.Sexual stimulation that leads to an erection causes the production and release of nitric oxide in the penis. The nitric oxide causes an enzyme, guanylate cyclase, to produce cyclic guanosine monophosphate (cGMP). It is the cGMP that is primarily responsible for increasing and decreasing the size of the blood vessels carrying blood to and from the penis, respectively, and causing the erection. When the cGMP is destroyed by another enzyme, phosphodiesterase-5, the blood vessels return to their normal size, blood leaves the penis, and the erection ends. Tadalafil prevents phosphodiesterase-5 from destroying cGMP so that cGMP stays around longer. The persistence of cGMP leads to a more prolonged engorgement of the penis with blood

[ Absorption ]    Tadalafil can be absorbed quickly after being taken orally, at the median time when is 2 hours after taking it, the plasma concentration reaches to the average observation maximum (Cmax). The absorptivity and absorption degree of Tadalafil is free of being influenced by foods, so it can be taken with or not with foods. The taking time (morning or night) has no effect in the absorptivity and absorption degree.