Sildenafil, which appeared on the market in the late 90s, is the first really effective drug that has helped solve the problem of erectile dysfunction to large number of men. According to statistics, about 150 million men from 18 years and older suffer from problems in sexual life and urination due to the disorder of blood circulation in the pelvic. One of the most popular and effective drugs for symptomatic treatment is Viagra. Today there are not less popular counterparts, and namely, German Levitra, American Cialis and other, but nevertheless, sildenafil keeps its position. Thanks to a big advertising campaign and truly innovative features, the drug is known all over the world.
Its high efficiency is specified by an incidental finding and synthesizing the compound – sildenafil – which acts selectively only for a particular process in the smooth muscle. In order to understand how Viagra works the mechanism of erection appearance and preventing factors should be examined.
What is the process of erection? It is basis is hemodynamics or blood flow through the vessels in an area of low pressure. Smooth muscle of the cavernous body should be relaxed, nitric oxide is released in the body at the sexual arouse, more and more blood rushes to the penis, it swells and this is a natural reaction to the stimulation. But if the walls of the vessels resist the movement, the blood becomes more viscous, the difficulties arise and the process stops. The matter is that while the release of nitric oxide an enzyme that breaks down cGMP, a nucleotide in the RNA composition also begins to "work". And nitric oxide has no time to release in a sufficient amount; the enzyme continues to interfere with the rush of the blood. Viagra stops it. Thus during the arousal no physiological process does not prevent to occur the natural and normal erection.
Sildenafil acts solely in relation to this enzyme – phosphodiesterase-5. Other isoenzymes it influences ten times less, i.e., does not compromise load to the heart, brain and other major organs. Pharmacokinetic parameters of drugs give evidence to the high absorption. In average, it is needed about an hour to reach a peak content of sildenafil. The time for intimacy should be planned in these time frames.
The preparation does not influence the indicators of sperm quality, within two hours after administration the admission to the semen contains less than 0, 0002% of the dose. Participation in metabolism: sildenafil is metabolized in the liver and excreted mainly by an intestine.
1. The drug helps to strengthen and maintain erectile function. It does not treat, but only improves the blood supply.
2. Increases the duration of sexual intercourse and speeds up the recovery period.
3. Increases blood flow in the genitourinary system, which is useful for all of the pelvic organs and helps cure some diseases.
4. Practically does not have side effects at all the positive effects for sexual life.
5. Overdosing does not lead to dangerous health results (on condition that the patient is not at risk group for cardiovascular diseases or renal and liver failure).
6. Can be used at any age from 18 years.
7. Not addictive.
8. Allows to get rid of impotence even in complex cases.
9. Does not affect the quality of the semen and may be taken before planned conception.
The drug is taken continuously or once. An urologist prescribes the scheme of the medicine administration. Calculation of dosage depends on many factors. Administration conditions: tablet should be taken at least 30 minutes prior to sexual contact. It should be taken with plenty of water (not cold). The combination with fatty food will worsen the absorption and delay the onset of action of the drug. It is prohibited to take with alcohol and drugs containing organic nitrates.
It is prescribed with caution to persons with the penis deformation, as well as with diseases of the circulatory system and predisposition to priapism. The contradictions for Viagra take are the following diseases: stomach ulcers (among the side effects dyspepsia is noted), acute heart failure, angina, aggravating during sexual intercourse, severe arrhythmia, blood pressure below 90/50 and above 170/100 mm Hg.
Only 10% of patients registered side effects. They are the following: headache, dizziness, face hyperemia, hypertonia, tachycardia, impairment of vision, rhinitis, and dyspepsia.
It is not recommended to take the tablet in a state of alcoholic inebriation – in this case even a small dose of alcohol can be harmful for blood circulation in the pelvic organs and sildenafil will not have the desired effect. Also, fatty food slows the absorption of the drug and consequently delays the beginning of its action, i.e. instead of 30-60 minutes from the intake Viagra will work only after 120 minutes.