Sildenafil Citrate 99.98% High Purity Viagra Safe Effective Sex Enhancement Powder CAS 171599-83-0

Sildenafil Citrate

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Product Name : Sildenafil Citrate

Trade Name: Viagra

Description:

This product is an oral drug for the treatment of penile erectile dysfunction (ED). It is the citrate salt of sildenafil, a selective inhibitor of phosphodiesterase type 5 (PDE5) specific for cyclic guanosine monophosphate (cGMP). Mechanism of Action: The physiological mechanism of penile erection involves the release of nitric oxide (NO) in the corpus cavernosum during sexual stimulation. The activation of guanylate cyclase by NO leads to an increase in the level of cyclic guanosine monophosphate (cGMP), which relaxes the smooth muscle in the cavernous body and fills the blood.

The effect of sildenafil on penile erectile response: sildenafil is a highly selective phosphodiesterase 5 (PDE5) inhibitor, PDE5 is highly expressed in the corpus cavernosum, while in other tissues (including platelets, blood vessels and Visceral smooth muscle, skeletal muscle), low expression. Sildenafil selectively inhibits PDE5, enhances the nitric oxide (NO)-cGMP pathway, and increases the level of cGMP to cause the relaxation of the smooth muscle of the cavernous body of the penis, so that patients with erectile dysfunction can produce a natural erectile response to sexual stimulation. Erectile response generally increases with increasing dose and plasma concentration of sildenafil. Experiments have shown that the drug effect can last up to 4 hours, but the reaction is weaker than that at 2 hours. The response of sildenafil to myocardium: PDE5 does not exist in normal or diseased cardiac conduction tissue, cardiomyocytes, endothelial cells, and lymphoid tissues, so sildenafil (PDE5 inhibitor) has no positive inotropic effect and cannot Directly affect myocardial contractility.

Effects of sildenafil on cardiac parameters: Normal male volunteers took a single dose of 100 mg sildenafil orally, and no clinically significant changes in the electrocardiogram occurred. Under the monitoring of Swan-Ganz catheter, 8 patients with stable ischemic heart disease were injected intravenously with a total of 40 mg of sildenafil in 4 times. fell by 7% and 10%, respectively. Resting right atrium, pulmonary artery pressure, pulmonary artery wedge pressure, and cardiac output decreased by an average of 28%, 28%, 20%, and 7%, respectively. Although this intravenous dose is 2 to 5 times higher than the average peak plasma concentration of sildenafil 100 mg given by a single oral dose of healthy male volunteers, the above-mentioned hemodynamic response still exists during exercise.

The response of sildenafil to blood pressure: a single oral dose of 100 mg sildenafil in healthy male patients resulted in a drop in supine blood pressure (the average maximum amplitude was 8.4/5.5mmHg). The drop in blood pressure was most obvious 1-2 hours after taking the drug, and 8 hours after taking the drug No difference from placebo group. 25mg, 50mg, and 100mg sildenafil have similar effects on blood pressure, which seem to have nothing to do with drug dose and blood drug concentration. The antihypertensive effect was greater in patients taking nitrates at the same time. Hypotension (90/50 mmHg) and nitrates or drugs that provide nitrates are strict contraindications to the use of sildenafil. The maximum effect of sildenafil on blood pressure occurs about 1 hour after administration, which is consistent with the peak plasma level of the drug. Therefore, sexual activity may induce cardiac events at peak plasma drug concentrations of sildenafil. Although the hypotensive response induced by sildenafil was mild and transient (blood pressure returned to baseline within 4 hours, generally), the interaction between sildenafil and nitrates produced a significant and prolonged reduction in blood pressure. Sildenafil has a short half-life, and the drug can be eluted within 24 hours (about 6 half-lives). The American College of Cardiology and the American Heart Association have clearly pointed out that sildenafil is prohibited for those who have used nitrates within 24 hours.

The effect of sildenafil on vision: Studies have shown that when taking 2 times the maximum recommended dose of the drug, this product has no effect on vision, electroretinogram, intraocular pressure and optic disc size. There may be transient blue/green color discrimination abnormalities. Whether used alone or in combination with aspirin, this product has no effect on human bleeding time. In vitro experiments, this product enhanced the anti-human platelet aggregation effect of sodium nitroprusside (NO donor). In anesthetized rabbits, the combination of heparin and sildenafil has an additive effect on prolonging the bleeding time, but no similar human studies have been conducted. After a single oral dose of sildenafil 100mg in healthy volunteers, the motility and morphology of sperm were not affected.