| Approximately 140 million men worldwide are estimated to suffer from sexual dysfunction. Over than 50% of all males with erectile dysfunction are believed to have some physical (medical) condition. The remainder are thought to have psychological causes of impotence. Diabetes and circulatory, nerve damage or urological conditions are medical causes of impotence.
Penile erection occurs when the blood vessels carrying blood to the organ boost the delivery of blood and the blood stream from the penis declines. In healthy men, sexual arousal leads to the production and release of nitric oxide in the penis. Afterwards, nitric oxide activates the enzyme - guanylate cyclase - which brings on the production of cyclic guanosine monophosphate (cGMP). It is the cGMP that is mainly responsible for the erection by controlling the quantity of blood that the blood vessels dilever and carry away from the penis.
Viagra (sildenafil) is prescribed for the treatment of impotence of either medical or psychological cause. Sildenafil is a blue, coated, rounded tablet that comes in 25, 50, and 100 mg tablets. Viagra inhibits an enzyme known as phosphodiesterase-5 (PDE5) which destroys the cGMP. Hence, Viagra precludes the destruction of cGMP and allows cGMP to increase in quantity and persist longer. The longer cGMP persists, the more lengthened the engorgement of the penis.
Sildenafil is rapidly absorbed. Maximal observed plasma concentrations are reached within 30 to 120 minutes after oral administration in the fasted state. When sildenafil is taken with a fatty meal, the rate of absorption reduces.
Sildenafil increases the effects of heart medicines and nitrates that are taken primarily for curing angina. Hence, drug interactions with heart medications and nitrates can be dangerous.
Around 15% of patients taking Viagra experience side effects. The most common side effects are pounding headaches, dyspepsia, facial flushing and visual changes. Infrequentcases of sudden loss of hearing have been observed with phosphodiesterase inhibitors, such as sildenafil, sometimes with ringing in the ears and lightheadedness.
Before taking Viagra, consult your doctor. |
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