what does viagra do?

Question

can anyone tell me?

Answer 1

It can keep you up most of the night.

Answer 2

It was originally made as a heart medication. The 'happiness' is just a side effect.

Answer 3

It allows more blood to flow "down there" -- but it doesn't make you horney. Plus, it doesn't give you better sex. You have have a hard one and not know what to do with it. Even a semi soft one can be better with proper use than a hard one with no idea! :)

Answer 4

It's supposed to help men with erectile dysfunction to get an erection, but some use it for other purposes...

Answer 5

gives you a raging ***** that is not supposed to last longer than 4 hours.

I didn't realize B O ner was a swear word...that's dumb

Answer 6

It makes Mr Dinkle very big and strong!

Answer 7

Restricts blood flow. when a male has an erection the blood vessels contract causing the erection to stay full of blood, in turn holding the erection.

Answer 8

I think that it allows more bloodflow to the penile tissue in order to produce an erection in a man.

Answer 9

Isn't it obvious from the commercials?
It makes you smile a lot.

Answer 10

well...

Sildenafil citrate, sold under the names Viagra, Revatio and generically under various other names, is a drug used to treat male erectile dysfunction (impotence) and pulmonary arterial hypertension (PAH), developed by the pharmaceutical company Pfizer. Viagra pills are blue and diamond-shaped with the words "Pfizer" on one side and "VGR xx" (with xx representing 25, 50 or 100, the dose of that pill in milligrams) on the other. Its primary competitors on the market are tadalafil (Cialis), and vardenafil (Levitra).

Mechanism of action
Part of the physiological process of erection involves the parasympathetic nervous system causing the release of nitric oxide (NO) in the corpus cavernosum of the penis. NO binds to the receptors of the enzyme guanylate cyclase which results in increased levels of cyclic guanosine monophosphate (cGMP), leading to smooth muscle relaxation (vasodilation) in the corpus cavernosum, resulting in increased inflow of blood and an erection.

Sildenafil is a potent and selective inhibitor of cGMP specific phosphodiesterase type 5 (PDE5) which is responsible for degradation of cGMP in the corpus cavernosum. The molecular structure of sildenafil is similar to that of cGMP and acts as a competitive binding agent of cGMP in the corpus cavernosum, resulting in better erections. Without sexual stimulation and no activation of the NO/cGMP system, sildenafil should not cause an erection. Other drugs that operate by the same mechanism include tadalafil (Cialis®) and vardenafil (Levitra®).

Sildenafil is metabolised by hepatic enzymes and excreted by both the liver and kidneys. If taken with a high fat meal, there may be a delay in absorption of sildenafil and the peak effect might be reduced slightly as the plasma concentration will be lowered.

Some reports have claimed that sildenafil causes enhanced sexual pleasure for women by increasing blood flow to the sexual organs. This lacks firm evidence, and it has also been suggested that this is part of an effort to invent a new disease - female sexual dysfunction - thus doubling the potential size of the market for this class of drugs.

Other uses
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Pulmonary hypertension
As well as erectile dysfunction, sildenafil citrate is also effective in the rare disease pulmonary arterial hypertension (PAH). It relaxes the arterial wall, decreasing pulmonary arterial resistance and pressure, and thus the strain on the right side of the heart thus improving symptoms of right-sided heart failure. Because the distribution of PDE-5, which is primarily in the arterial wall smooth muscle in the lungs and penis, sildenafil acts selectively in both these areas without inducing vasodilation in other areas of the body. Pfizer submitted an additional registration for sildenafil to the FDA, and sildenafil was approved for this indication in June 2005. The preparation is named Revatio, avoiding confusion with Viagra, and the 20 milligram tablets are white and round. Sildenafil joins bosentan and prostacyclins therapies for this condition[13].

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Raynaud's phenomenon
In 2005, Dr. Roland Fries and colleagues reported that sildenafil cut the frequency of Raynaud's phenomenon attacks, reduced their duration by roughly one half, and more than quadrupled the mean capillary blood velocity. This was a double-blind, placebo-controlled crossover trial and the patients had both the primary and secondary forms and had all discontinued the more conventional treatments for this[14].

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Cognitive enhancement
A recent study performed at the National Institute on Aging's Gerontology Research Center shows that sildenafil citrate may help to attenuate cognitive deficits associated with aging. Scientists found that in rats, administration of sildenafil citrate partially reversed the memory impairment produced by L-NAME, a nitric oxide synthase inhibitor implicated in the same cGMP signal transduction pathway as sildenafil. While it is too early to draw a firm conclusion, researchers seem optimisitic about the drug's promise in treating age-related neurodegeneration (PMID 16320087).

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Analgesia
Several studies have determined that sildenafil citrate demonstrates anti-nociceptive properties in rodents. While the effect seems to be greatest in diabetic animals, non-diabetic animals, too, show significant elevation in pain threshold (PMID 15452368). Current evidence seems to suggest that the cGMP that accumulates as a result of Phosphodiesterase 5 inhibition interacts with the cholinergic system to mediate this pain-reducing effect (PMID 15088685).

Answer 11

relaxes blood vessels.

the Army is actually testing it for the High Altitudes of Afghanistan