Sildenafil 25mg tablets

Sildenafil is an oral therapy used to treat Erectile Dysfunction in men.  The medication is referred to as a Phosphodiesterase type 5 inhibitor (PDE5 inhibitor)

Mechanism of Action (how it works):

During sexual stimulation Nitric Oxide(NO) is released in the corpus cavernosum of the penis. NO activates an enzyme called guanylate cyclase which results in increased levels of cyclic guanosine monophosphate (cGMP).  cGMP promotes smooth muscle relaxation in the corpus cavernosum  allowing a greater inflow of blood to the area.  This results in a firmer and fuller erection.  Sildenafil has no direct relaxant effect on the corpus cavernosum but enhances the effect of NO by inhibiting PDE5 which is responsible for the degradation (breakdown) of cGMP in the corpus cavernosum.  So, basically, inhibiting PDE5 allows the concentration of cGMP to rise which is what you want to relax the area and allow greater blood flow.