The Blue pill or Magic pill sold under the names Viagra, Revatio and generically under various other names was approved by the FDA (Food and Drug Administration) in 1998 as the first non-surgical treatment option for erectly dysfunction that doesn't require be inserting or injecting directly in the man's penis. Viagra which brand name is sildenafil citrate surprisingly, such modern and innovative was nearly discovered by accident. Originally, the drug was tested by Pfizer Pharmaceuticals as a heart medication. Those studies were stopped in 1992 due to unsatisfactory results of the medication in patients suffering from chest pain.

However, Pfizer researchers notice some properties in the sildenafil citrate that may shed a light on the treatment for erectile dysfunction. Tests so proved that the substance could really be a hope for men that weren’t able to maintain an erection long enough to engage in normal sexual activity.

Clinical trials involved patients with age ranging from 19 to 87 who had a condition of erectile dysfunction due to the following problems: serious spinal cord injury, diabetes, history of prostate surgery and also patients with no identifiable cause of sexual dysfunction. Some of the patients also presented coexisting problems such as hypertension, and coronary artery issues. The various tests were held worldwide, with 3700 random patients, placebo-controlled, leading to the approval of the sildenafil citrate only six months later, since the results were very satisfactory and presented no significant side effects.

What is Viagra™?

Viagra™ (sildenafil citrate) is a medication made by Pfizer Pharmaceuticals, and is the first approved non-surgical treatment for erectile dysfunction (ED) that does not have to be either injected or inserted directly into the penis to achieve and maintain an erection. It was approved by the US Food and Drug Administration (FDA) for prescription sale at the end of March, 1998.

Development history of Viagra:

Originally developed by Pfizer as a drug to help men who were suffering from chest pain, sildenafil citrate as a heart medication did not show promise and studies were stopped in 1992.
However, based on published information about some properties contained in sildenafil citrate, Pfizer researchers began to look at it as a treatment for erectile dysfunction. It was re-evaluated for its effect on the ability of men with ED to engage in sexual activity, and the ability to achieve and maintain erection sufficient for satisfactory sexual activity.
Eventually, 21 randomized, placebo-controlled clinical trials involving more than 3700 patients, ages 19 to 87 years, were held worldwide. The participants had varying degrees of impotence associated with the following:

• diabetes
• spinal cord injury
• history of prostate surgery
• no identifiable organic cause

Some patients also had coexisting illnesses, including hypertension and coronary artery disease.

The clinical trials found Viagra to be so effective, the FDA approved it only six months after submission, and without consulting an advisory committee of outside experts because there were no troubling questions and no significant side effects.

What are the side effects of Viagra?

In the clinical trials, when Viagra was taken on an as-recommended and as-needed basis, the following adverse events were reported:

• headache - 16 percent with Viagra; 4 percent with the placebo
• flushing - 10 percent with Viagra; 1 percent with the placebo
• indigestion - 7 percent with Viagra; 2 percent with the placebo
• nasal congestion - 3 percent with Viagra; 2 percent with the placebo
• urinary tract infection - 3 percent with Viagra; 4 percent with the placebo
• mild and temporary visual changes (blue/green color perception changes, light perception changes, and blurred vision) and also increased sensitivity to light or blurred vision. - 3 percent with Viagra; 0 percent with the placebo
• diarrhea - 3 percent with Viagra; 1 percent with the placebo
• dizziness - 2 percent with Viagra; 1 percent with the placebo
• rash - 2 percent with Viagra; 1 percent with the placebo

Side effects that occurred less than 2 percent included respiratory tract infection, back pain, flu syndrome, and arthralgia.

How does Viagra work?

The erection of the penis involves release of nitric oxide (NO), a chemical that is normally released in response to sexual stimulation, in the corpus cavernosum of the penis.

• Nitric oxide then activates an enzyme called guanylate cyclase, which, in turn, results in increased levels of cyclic guanosine monophosphate (cGMP).
• This produces smooth-muscle relaxation in the corpus cavernosum and allows the inflow of blood.

[There are three types of muscles: smooth, cardiac, and striated. Smooth muscles are those that are involuntary in action and are found principally in internal organs.]

• Viagra (sildenafil citrate) has no direct relaxant effect on the human corpus cavernosum.
• Instead, sildenafil enhances the effect of nitric oxide (NO) by inhibiting phosphodiesterase type 5 (PDE5).
• PDE5 is responsible for degradation of cGMP in the corpus cavernosum, which causes the penis to become flaccid, or relaxed.
• When sexual stimulation causes local release of NO, sildenafil inhibits PDE5, which, in turn, causes increased levels of cGMP in the corpus cavernosum. This results in continued smooth-muscle relaxation, allows for inflow of blood to the corpus cavernosum, and erection of the penis.
• Sildenafil at has no effect in the absence of sexual stimulation.

The use of the sildenafil citrate is controlled since its efficacy was proved. Since then, its potential cost was the primary reason why the substance is not used in a larger scale. Either for the health services or patients who would have a Viagra prescription, the price is still high, although significantly cheaper in comparison to the other types of treatment available. The amount of people looking for a Viagra substitute or a manner to low the costs ended up leading to illegal sales, contraband and manufacturing of low-quality illegal Viagra imitations. Those imitations are strongly not recommended. It’s impossible to know what was used in the pill, and it can be extremely dangerous. The only safe way to buy Viagra is in a well-known and trustworthy drugstore (it does not include any kind of sex shop). You can also order Viagra online in virtual drugstores, where you can also get Viagra samples, but depending of the country, there can be ethic, legal or safety issues.

There are several other substances being tested (particularly in the U.K.) to produce new medications to control disorders of the male sexuality. Researchers believe that within the next few years, those Viagra Alternatives will be available, presenting more efficacies in the inhibition of the phosphodiesterase type 5 and fewer side effects. It is also expected scientists to produce drugs that may act directly upon the brain, bringing even better results.

Sources:

Pfizer
US Food and Drug Administration
University of Utah Health Sciences Center
Men’s Health
History of sexuality

Tag: Viagra the Blue pill