Viagra

Viagra - Erectile Dysfunction Pill

Viagra Chemical Composition

Viagra is the most popular, well-known and widely-marketed product used for treatment of erectile dysfunction. Viagra’s scientific name is Sildenafil, “C22H30N6O4S” is the chemical formula of Viagra. Viagra’s bioviability is 40% and half life is from three to four hours. Besides Viagra, Sildenafil is sold under such trade names as Revatio and other. Treatment of erectile dysfunction, although, is not the only use of Sildenafil, as it is also starting to be used for treatment of PAH (pulmonary arterial hypertension). Since it became available back in 1998, Viagra has become the most popular medicine for treatment of ED and other sexual problems for males. Viagra has lots of nicknames among people, which include “The Blue Pill”, “Vitamin V” and many others. There is no other drug, which ever became as popular as Viagra, not only due to it’s marketing, but also because of its amazing effects and minor negative influence on the body.

Pfizer

Viagra History

Viagra was developed and sold by the most popular pharmaceutical company, producing erectile dysfunction treatments – PFIZER. Sildenafil was first synthesized by a small group of chemists professional in the area of pharmaceutics in Kent, England. Viagra was tested in Swansea in Morriston Hospital. Viagra received it’s patent under Pfizer company in 1996, which will expire in 2011-2013. It was also approved for sales in the United States of America by the American Food and Drug Association in March of 1998. It was the very first oral erectile dysfunction treatment medication, which was approved by the FDA. Since 1998 Viagra was offered for sales by Pfizer on the territory of the United States and became extremely successful by reaching over $1B of yearly sales in 1999 – 2001. In 2000 sales of Viagra made up about 92% of the worldwide market of prescription erectile dysfunction treating drugs. As for now, Viagra has about 50% of share in the global market of prescription ED treatments, mostly due to strong emerging of its major competitors – Cialis and Levitra.

Viagra General Links:

1. Viagra.com – Official Site
2. Erectile Dysfunction Drug Viagra Launched In India By Pfizer. (about generics)
3. AIDS Healthcare Foundation Launches Ad Campaign Against Pfizer’s Ads Promoting Erectile Dysfunction Drug
4. Viagra Ads. (video)
5. Viagra Ads 2. (video)
6. Viagra Ads 3. (video)
7. Six Viagra Myths. (article)

Viagra Dosage

Viagra Dosage

Viagra is sold in a form of pills, which are usually blue and shaped in the form of diamonds. Revatio pills are white and round with a film coat. They have “RVT20” on one side of each pill. Pfizer Viagra pills have “Pfizer” name on one side and “VGR 00” engraved on another. In the place of 00 the dose is usually put. Viagra is supplied in different doses: 25 mg, 50mg or 100 mg. The dose is prescribed by a doctor and is a daily dose, which should not be exceeded. Viagra usually starts acting less than one hour after taking the pill, so depending on the dose and your personal performance, Viagra pills should be taken half an hour to four hours before the sexual intercourse. When Viagra is used for treatment of arterial hypertension, then a 20mg dosed pills should be taken three times a day.

Viagra Dosage Links:

1. Man, 28, Dies From Viagra Overdose During Orgy. (news)
2. Glamorous City Shindig Shaken by Viagra Overdose Scandal. (news)
3. Viagra Overdose Gives User Blue Vision. (news)
4. Viagra Overdose. (funny picture)

How Viagra Works

Viagra works by regulating blood flow into the penis using enzymes. Sildenafil inhibits cyclic GMPs of type 5 (specific phosphodies terase). Viagra operates by releasing nitric oxide into penis (directly into the corpus cavernosum). When Viagra starts working, muscles become more relaxed. This results in better flow of blood into the penis, and erection, as a result. Viagra inhibits cyclic GMP of type 5. The structure of molecules of Sildenafil is very similar to that of the cyclic GMP. It can act as the competitive agent for binding of PDE5 elements in the penis. Viagra does not cause sexual arousing, unless there is some kind of sexual stimulation used. After use of the medicine, Viagra elements stay in the body for some time, and later are excreted by liver and kidneys.

Viagra is an oral medication used for treating of erectile dysfunction, which is only sold and should be taken according to doctor’s prescription. It is advised to take Viagra with a light meal or without a meal, as combination of Viagra with a hard high-fat meal decreases its absorption and therefore increases the time needed to receive results from the Viagra medicine. If you take Viagra with a fat meal, it is very likely, that the first results of the medicine will be visible after about 1 hour and 20 minutes, or up to 1 hour and a half, instead of 40 minutes to 1 hour.

Viagra is a prescription-only drug, but it is widely advertised on TV and street advertising directly to its potential consumers. Viagra is used for erectile dysfunction treatment and not only helps get an erection, but also to sustain it long enough to complete a sexual activity successfully. Viagra can be used even by patients suffering from diabetes. There are different causes of problems with erection or partial ED. Viagra can help almost in any case and not depending on the reason of erectile dysfunction. Another use of Viagra includes use for treatment of pulmonary arterial hypertension. Because Sildenafil is able to relax walls of arteries, it can easily decrease the pulmonary resistance and pressure of arteries. As a result of these actions of Viagra, it is easy to decrease the load on the heart and avoid heart strokes and other heartaches. Viagra is sometimes used in sports, as its effects of opening the blood vessels can help enrich muscles, therefore enhance the performance of athletes. Viagra is also used in recreational purposes, or better say is abused, as there is no point in taking Viagra by men, who do not suffer from erectile dysfunction. Among young people, who abuse illegal substances, it is especially popular to mix Viagra with MDMA or ecstasy. But it is very dangerous to mix Viagra with some medications, especially those containing nitrates, and such combinations should be avoided.

Viagra Works Links:

1. How Viagra, Levitra, and Cialis Work. (video)
2. When Viagra Doesn’t Work
Treating Erectile Dysfunction (article)
3. Viagra Doesn’t Work For Women. (news)
4. Viagra not working? Check Your Testosterone Levels (article)
5. Viagra vs. Cialis vs. Levitra: Differences and Similarities. (article)

5 Comments

  1. Scott :

    Feb 10, 2010 11:51 am |


    PDE-5 inhibitors are a group of effective drugs for the treatment of ED. Viagra is the only oral treatment for erectile dysfunction, available in the U.S., and Cialis and Levitra have recently been approved for use in Europe. Since Viagra is the only PDE-5 inhibitor used in the U.S., in this article we will focus on its use in cardiological patients.
    Viagra acts by inhibiting the enzyme PDE-5, which breaks down cyclic guanosine monophosphate (cGMP). That cGMP leads to relaxation of smooth muscle cells of arteries, arterioles and sinusoids of the cavernous body of penis. NO, secreted nerve endings and endothelium during sexual stimulation leads to activation of the enzyme guanylyl, which catalyzes the formation of cGMP. Its amount may be impaired in men with ED. Thus, PDE-5 inhibitor, Viagra prevents the collapse of cGMP, which leads to greater vasodilation in the cavernous bodies and better erections. Cialis and Levitra act through similar mechanisms.
    Receiving 100 mg Viagra leads to improved erections in 82% of patients with ED. The drug is effective in patients with organic and psychogenic ED. Patients with ED and coronary artery disease (and, presumably, or atherosclerotic vascular causes of erectile dysfunction), Viagra was effective in approximately 70% of cases. Studies the effectiveness of Viagra in patients with hypertension Viagra was safe and improved erections in 70-72% of patients. Moreover, it was effective in patients who received one, two, three or more drugs for the treatment of hypertension. This is important because some antihypertensive drugs can impair erectile function. Thiazide diuretics, b-blockers and drugs acting on the central level, are the most likely examples of such drugs. Calcium channel blockers and ACE inhibitors are less likely as causes of ED. Recently there have been several interesting studies, suggest that angiotensin receptor antagonists are in fact able to improve erectile function. There was no evidence of increasing frequency of serious cardiovascular complications such as angina, myocardial infarction or cardiac death in patients with coronary artery disease or hypertension who received Viagra.

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    The enzyme PDE-5 is localized in vascular smooth muscle cells of the corpora cavernosa, as well as in smooth muscle cells of systemic arteries and veins, smooth muscle cells of the gastrointestinal tract and in platelets. Due to the fact that PDE-5 is located in the smooth muscle cells of systemic arteries and veins, with its marked inhibition of mild vasodilation, with the hemodynamic effect resembles the action of weak nitrate. Therapeutic doses of Viagra reduced blood pressure by about 8 mmHg and diastolic pressure by about 5-6 mm Hg. In most cases this reduction is not felt by patients. Viagra reduces systemic vascular resistance and has no appreciable effect on heart rate. It does not increase myocardial contractility and reception in therapeutic doses has no adverse effect on the interval QT. In a study of patients with severe coronary artery disease treated with Viagra in the laboratory for cardiac catheterization, Viagra did not alter the diameter of the coronary arteries and blood flow velocity in them. He showed a weak positive effect on increasing coronary reserve in response to the action of adenosine and did not cause.

    Several studies have confirmed the safety of Viagra in patients with coronary artery disease undergoing exercise testing. In one study has even been suggested that Viagra increases the exercise tolerance and increases the ischemic threshold. The importance of these studies is that patients perform exercises with a load comparable to the loads that have occurred during sexual intercourse. Several similar studies have confirmed the safety of Cialis and Levitra in patients with coronary artery disease in the performance of exercise testing.
    Early analysis of occurrence of myocardial infarction and death in a double-blind, placebo-controlled studies were comparable in patients receiving Viagra and placebo. Open studies have shown lower rates while taking Viagra compared with placebo. The British study administered substances found no evidence proving the increased frequency of cardiovascular events while taking Viagra have thousands of men, compared with the total male population in England. Similar but less extensive studies Cialis also showed no increase in the frequency of myocardial infarction or death among patients receiving the drug, compared with patients receiving placebo or a similar age group from the general population. FDA has also published data show that mortality among men taking Viagra, was within the expected rates for men of this age. Thus, despite sporadic reports of the development of cardiovascular complications in patients taking Viagra, a thorough analysis of the frequency of such events among patients receiving Viagra, compared with patients of similar age, who may develop erectile dysfunction, has shown that Viagra does not lead to such phenomena. Although sexual activity in rare cases can cause the development of myocardial infarction, the absolute number of such cases is small. Given that Viagra may allow a man to resume sexual activity, different societies, for example, the American College of Cardiology and American Heart Association created a recommendation regarding the appointment of Viagra cardiac patients. In addition to the contraindications to the appointment of Viagra to patients taking nitrates (eg nitroglycerin, isosorbide dinitrate and isosorbide mononitrate), these societies and authors Prinsentonskih conciliatory recommendations believe that we should be wary of the appointment of Viagra in patients with unstable heart disease. It should be noted that this assumption is highly questionable, especially given the fact that patients with unstable heart disease indeed (eg, unstable angina, myocardial infarction and severe heart failure), rarely turn to doctors for the treatment of sexual disorders.

    Due to the fact that PDE-5 inhibitors are weak vasodilators, some doctors fear assign them patients taking antihypertensive drugs, for fear of hypotension. Most studies have shown no or little additional reduction in pressure in the appointment of PDE-5 inhibitors in combination with antihypertensive agents. The preparation of the group a-blocker doxazosin, made jointly with PDE-5 inhibitor Viagra, has led to orthostatic hypotension in only a small number of patients that require the abolition of the contraindications to the joint reception of these drugs within 4 hours. Cialis does not lead to additional reduction in blood pressure during the joint reception with amlodipine, but the decrease in pressure observed when combined with angiotensin receptor blockers to. It also led to a slight drop in pressure at admission, together with diuretics, b-blockers and ACE inhibitors. The small reduction in blood pressure also occurred at a joint reception of vardenafil with various antihypertensive drugs. Thus, inhibitors of PDE-5 can lead to a slight decrease in blood pressure. PDE-5 inhibitors are effective in treating erectile dysfunction in patients with arterial hypertension. In general, no significant increase in the frequency and severity of side effects of PDE-5 inhibitors in patients receiving antihypertensive drugs compared with those who have not received them.

    Organic nitrates such as nitroglycerin, are NO donors and increase the production of cGMP. PDE-5 inhibitors prevent the collapse of cGMP. In a joint reception of both drugs may increase the level of cGMP, sufficient for the development of significant hypotension in some patients. As a result, nitrates are the only contraindication to receiving Viagra in the United States. Some cases of deaths of patients taking Viagra, were due to the simultaneous intake of nitrates. Interaction with nitrate as described for Cialis, and it is likely that the contraindication regarding the admission of nitrates will be common to the entire class of PDE inhibitors in general. If the patient received Viagra, and he developed an episode retrosternal pain in the recommendations of the conciliation of the American College of Cardiology and American Heart Association indicates that the nitrates can not be applied within 24 hours after taking Viagra to happen drug excretion from the body for period equal to six half-life. Recent preliminary data suggest that interaction with nitrates may disappear within 4 hours after taking Viagra. It is possible that the opportunity to interact with nitrates will be longer while taking Cialis, since the long half-life of the drug is 17.5 hours. If the patient has an inhibitor of PDE-5, and he developed retrosternal pain, there are other antianginalnye / anti-ischemic drugs that can be used instead of nitrate. They include b-blockers, calcium channel blockers, oxygen, acetylsalicylic acid and morphine. Patients with myocardial infarction, who took an inhibitor of PDE-5, can receive conventional treatment (acetylsalicylic acid, thrombolytic therapy, percutaneous intervention) with the exception of nitrates.

    Two studies have shown that Viagra can improve endothelial function. In one study, patients with diabetes Viagra improved rapidly decreased dilation of the brachial artery. In addition, the daily intake of Viagra for several weeks resulted in better expansion of blood vessels, which suggests that long term administration may lead to long-term patronage of vascular disease in patients with diabetes. In another study, Katz et al. showed that patients with congestive heart failure have a lower degree of expansion of the brachial artery after compression. Viagra improved the figure, while the effect was dose-dependent.
    PDE-5 is distributed in the vessels of the lungs. Several studies have shown that Viagra reduces pulmonary vascular resistance and pressure in the pulmonary artery and improves cardiac output in patients with primary and secondary pulmonary hypertension (which occur with scleroderma and other). Given that pulmonary hypertension poorly to treatment, the emergence of new drugs is viewed with enthusiasm. Sildenafil has an additional positive effect on pulmonary hemodynamics while taking it together with pulmonary vasodilator iloprost or inhalation of NO. Large-scale multicenter studies are currently in the planning stage.
    Recent studies suggest that Viagra has the additional advantage of providing improved END in patients with heart failure. Bocchi et al. [48] studied the effect of oral Viagra in 23 patients with congestive heart failure (in most cases 2 and 3 classes) during exercise testing. Viagra reduces heart rate and blood pressure before and during the 6-minute test tredmile. Viagra increased the maximum oxygen consumption during load time and improved performance of exercises with 12.3 to 13.7 minutes (p = 0,003). In the preliminary report Lachmann et al. describe patients with heart failure, performing load cycling with maximum intensity. The next day they performed right heart catheterization. Viagra improved efficiency, maximum oxygen consumption and cardiac output against the background of the exercises. It also reduced the peripheral resistance during rest and increased the stroke volume during rest and during exercise. These data, combined with the data of Katz et al., showing improving vascular function while taking sildenafil, suggest that studies of long-term effectiveness of sildenafil or other PDE-5 inhibitors are quite reasonable in patients with heart failure.

    Erectile dysfunction is often a consequence END. Smoking, lipid metabolism, diabetes, hypertension (the same risk factors as for coronary heart disease) are also associated with ED. ED may be an early sign of CHD. PDE-5 inhibitors can effectively treat patients with ED, including patients with atherosclerosis, coronary artery disease and hypertension. Has not been shown that inhibitors of PDE-5 can directly lead to cardiovascular complications. They should not be used in conjunction with nitrates. They are safe for most patients receiving antihypertensive therapy. PDE-5 inhibitors are primarily intended to treat angina, but in the process of research Viagra in these patients improved erections, which is primarily seen as a side effect, the result was the indication for the drug. Apparently, we have come full cycle, as currently developed an interest in application of Viagra in cardiac patients and especially patients with heart failure and pulmonary hypertension. In addition, there are other potential areas of application, as Viagra restores endothelial function and, possibly, has sosudoprotektivnym action. Viagra may be appointed to long-term prescription for patients with peripheral vascular disease and coronary heart disease, as well as a new antihypertensive drug.
    Note
    Since writing this article, vardenafil has been approved for use in the United States. In connection with the possibility of hypotension, a-blockers and nitrates is a contraindication to its use.

    [Reply]

  2. Mike :

    Sep 3, 2009 2:02 pm |

    Viagra is the best medicine for men like me! I can’t believe it affects me this way! I change women every week. It’s so interesting to discover the tastes of every woman. They are so different in bed. They are so yummy! I love sex! I love to have sex with different women: skinny and fat, tall and low. Viagra helps me to get an erection several times during the night. One thing that troubles me is that my erection can last for hours. Is it ok? Can anybody share their experience of taking viagra? Did you get long lasting erections? Sometimes it can last for 5 hours. I hope it’s not bad for my organism. I can’t imagine my life without viagra any more!

    [Reply]

  3. Adam :

    Sep 3, 2009 1:45 pm |

    I don’t like to speak about my sexual problems. Still I want others to not be afraid of this. Erectile dysfunction is a disease any man can suffer. For two years I was alone. I didn’t want to start any relationship because I couldn’t please my women. I was too shy to talk to my doctor and ask him to prescribe viagra to me. Recently I decided to try this medicine. I got viagra without a prescription. I was afraid it wouldn’t work because online pharmacies can sell fake medication. But it worked!!! I took a pill before having sex with a woman I really liked. I pleased her two times in a row! We are still dating, and she just loves my energy in bed.

    [Reply]

  4. S M LAHIRI :

    Aug 31, 2009 9:52 pm |

    CAN A DIABETIC PATIENT WHOSE SUGAR LEVEL IS AROUND 136 TO 160 CAN TSKE

    [Reply]

    admin Reply:

    Viagra has been tested and found effective for diabetes in men. Viagra works by helping to weaken the smooth muscle of the penis during sexual stimulation, allowing increased blood flow. In previous studies involving 21 patients, the use of Viagra to improve the quality of erections in 48% receiving doses of 25 mg and 52% of those receiving 50 mg. Larger study of 268 men with diabetes found improved erections in 56% of Viagra. For comparison, between 65% to 88% of men reported improved without diabetes.

    [Reply]

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