When it comes to the treatment of erectile dysfunction, today’s patients can find an extensive selection of remedies, including cheaper generic drugs. Primarily, generics provide producers of pharmaceuticals with a shortcut, decreasing the overall distance from the production line to the drugstore shelf. Specifically for sildenafil citrate, generic brands aim to use if only a slightly changed formulation to decrease the price without influencing the drug potency. Currently existing generic sildenafil instructions suggest that the patient will receive the same medical benefits as with the branded drug version.
Sildenafil (Viagra) works, essentially, as an inhibiting agent for phosphodiesterase (PDE). This enzyme degrades intracellular second messengers known as cyclic guanosine monophosphate (cGMP) and cyclic adenosine monophosphate (cAMP), in this way regulating intracellular signals. Of the entire PDE family, PDE-5 selectively acts on cGMP and is expressed not only in testicles but also in other parts of the reproductive organs. There have been reports on the fact that PDE-5 inhibitors improve sperm count, sperm motility and sperm morphology in patients with idiopathic dysfunction, which is the leading cause of male infertility. Another well-known effect of Viagra is, of course, the improvement of erectile function.
The most widely prescribed generic Viagra dosage is 50mg. In addition to the Viagra proper dose, patients receive recommendations on specifics of how to use the drug.
Similarly to all ED pills, Sildenafil 50–100mg requires sexual stimulation to help its user attain an erection.
Aside from involving in the mechanism of NO-mediated muscle relaxation, PDE 5 inhibitors stimulate Leydig cells present in the seminiferous interstitium to produce and secrete male hormones (such as testosterone) and supply testosterone to Sertoli cells. The latter ones are the exact cells providing the nourishing function during spermatogenesis. This makes Sildenafil a perfect candidate for the amelioration of infertility issues in addition to its erection-boosting effect.
In one study, sildenafil was administered to patients with oligospermia and low-motility spermatozoa for 12 weeks. As the result, Leydig cell secretion ability increased, as well as sperm concentration and sperm motility when the pre- and after-dosing semen was compared. This result suggested that the increase of cGMP by PDE-5 inhibitor stimulates the Leydig cell secretion ability and may lead to an increase in sperm concentration and sperm motility. Furthermore, the study authors proposed applying medicines like Vardenafil and Viagra for promoting spermatogenesis by influencing the patient’s Sertoli cells.
As for the field of ED treatments, the prevailing number of sildenafil users tend to unfailingly experience the erection-mending benefit of the drug already on the first (sometimes second or third) use. Long-term therapies with this medicine generally lead to a significant improvement in the patient’s ED symptoms.
Pulmonary hypertension is a general term for pathological conditions that manifest as an abnormal elevation of the pulmonary artery pressure. In general, pulmonary arterial hypertension (PAH) is diagnosed when the average pulmonary artery pressure in the lying position exceeds 25 mmHg. Sildenafil dosing, in these cases, is capable of bringing relief to PAH sufferers and the method itself has been receiving a positive feedback from many clinicians in the recent years.
The mechanism behind the action of sildenafil on PAH lies in the very same ability of the drug to control the levels of NO. The pathophysiology of pulmonary arterial hypertension mostly stems from a decreased NO production caused by vascular endothelial injuries; this, in its turn, is connected to the enhancement of expression and activity of PDE-5 in the cells of pulmonary artery smooth muscle and right ventricular myocardium. As Viagra enhances the NO production by blocking the PDE-5 activity, this allows the patient’s body to maintain a healthy level of vasoconstriction, as well as proliferation of the vascular smooth muscle.