Levitra is an oral drug used to treat erectile dysfunction. Sexual stimulation causes the production and release of nitric oxide from the nerves endings of the cavernous bodies of the penis hereby activating enzyme guanylate cyclase. Guanylate cyclase in its turn is responsible for production of cyclic guanosine monophosphate (cGMP). The cGMP causes widening and relaxation of the blood vessels carrying blood to the penis. Levitra prevents phosphodiesterase-5 enzyme from destroying cGMP and thus helps to support blood flow to the penis.

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