Mechanism of action
How does Cialis work?
When sexually stimulated, the arteries carrying blood through the penis relax. This allows more blood to flow into the organ where it is absorbed by a sponge-like area of tissue and creates the tumescence. This initial process of relaxation is triggered by the production of cyclic guanosine monophosphate (cGMP) in the muscle cells, but this process may be slowed or stopped if the body also produces phosphodiesterase type 5 (PDE5). Cialis and the other two leading brands work by preventing the production of PDE5. On its own, this has no effect on the penis because sexual stimulation is required for an erection to occur. Cialis is distinctive because any given dose is only fully eliminated from the body after a period of thirty-six hours, whereas both Viagra and Levitra lose their effectiveness after about six hours and are fully eliminated in between eight and ten hours.
This ability to persist within the body also makes Cialis of potential use in the treatment of PAH. Research scientists hypothesise that, as with impotence, the network of blood vessels in the chest and lungs is affected by excessive production of PDE5. If this is the case, the pulmonary artery in particular might remain constricted. Clinical trials are now testing whether Cialis, as a once-daily treatment, will dilate the artery and so ease the resistance to blood flow and generally lower the pressure in the blood vessels. If these changes were to occur, it would reduce the load on the valves serving the lower chambers of the heart. This would represent a significant medical breakthrough because post-mortem studies have consistently shown that untreated PAH is a major cause of a failure in the right ventricle.
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Talking to your Partner can
change a lot |
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Tips for ladies
How you can help your partner |
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| Why you should talk over certain problems with your doctor. And how to do it. |
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