NKOYO Koyogra 100mg Tablet For Erectile Dysfunction

Koyogra belongs to a group of medicines called phosphodiesterase type-5 (PDE-5) inhibitors. It works by helping to relax the blood vessels of penis, allowing blood to flow into penis. The physiologic mechanism of erection of the penis involves release of nitric oxide (NO) in the corpus cavernosum during sexual stimulation. NO then activates the enzyme guanylate cyclase, which results in increased levels of cyclic guanosine monophosphate (cGMP), producing smooth muscle relaxation in the corpus cavernosum and allowing inflow of blood. When sexual stimulation causes local release of NO, inhibition of PDE-5 by koyogra causes increased levels of cGMP in the corpus cavernosum, resulting in smooth muscle relaxation and inflow of blood to the corpus cavernosum. Koyogra at recommended doses has no effect in the absence of sexual stimulation.

In vitro studies have shown that koyogra is selective for phosphodiesterase-5 (PDE5) . Its effect is more potent on PDE5 than on other known phosphodiesterases . In particular, there is a 10-times selectivity over PDE6 which is involved in the phototransduction pathway in the retina . There is an 80-times selectivity over PDE1, and over 700-times over PDE 2, 3, 4, 7, 8, 9, 10 and 11 . And finally, koyogra has greater than 4,000-times selectivity for PDE5 over PDE3, the cAMP-specific phosphodiesterase isoform involved in the control of cardiac contractility .

In eight double-blind, placebo-controlled crossover studies of patients with either organic or psychogenic erectile dysfunction, sexual stimulation resulted in improved erections, as assessed by an objective measurement of hardness and duration of erections (via the use of RigiScan®), after koyogral administration compared with placebo . Most studies assessed the efficacy of koyogra approximately 60 minutes post-dose . The erectile response, as assessed by RigiScan®, generally increased with increasing koyogra dose and plasma concentration . The time course of effect was examined in one study, showing an effect for up to 4 hours but the response was diminished compared to 2 hours .

Koyogra causes mild and transient decreases in systemic blood pressure which, in the majority of cases, do not translate into clinical effects . After chronic dosing of 80 mg, three times a day to patients with systemic hypertension the mean change from baseline in systolic and diastolic blood pressure was a decrease of 9.4 mmHg and 9.1 mmHg respectively . After chronic dosing of 80 mg, three times a day to patients with pulmonary arterial hypertension lesser effects in blood pressure reduction were observed (a reduction in both systolic and diastolic pressure of 2 mmHg) . At the recommended dose of 20 mg three times a day no reductions in systolic or diastolic pressure were seen .