Viagra

Viagra is a drug used to treat erectile dysfunction in men.

Originally, it was synthesized for the treatment of angina pectoris and other cardiac diseases. However, after clinical trials in 1992, it was found that the action of the tablets had practically no effect on the blood flow to cardiac muscle. Otherwise, it provokes the blood flow increase to the cavernous bodies.Viagra_ Potent ED Drug

Composition

The active and basic substance is Sildenafil. The auxiliary components include:

  • anhydrous calcium hydrogen phosphate;
  • magnesium stearate;
  • croscarmellose sodium;
  • titanium dioxide (E 171);
  • triacetin;
  • Hypromellose;
  • indigo carmine aluminum varnish (E 132);
  • lactose.

Indications

Viagra is recommended for men suffering from erectile dysfunction, which is explained by the inability to achieve or maintain an erection. Such a lack prevents successful sexual intercourse. For the effective action of this drug, sexual excitement is necessary.

Mode of application

This drug is intended for oral administration.

The recommended daily Viagra dose for adults is 50 mg. It is taken approximately 1 hour before sexual intercourse. Given the effectiveness and tolerability, the dose can be increased to 100 mg or reduced to 25 mg. The maximum recommended dose is 100 mg.

The frequency of use of the maximum recommended drug dose is 1 time per day. When using this drug during meals, its effect may occur later than when it is used on an empty stomach.

Elderly patients: there is no need for dose adjustment in elderly patients (≥65 years).

Patients with renal failure; for patients with mild to moderate renal failure (creatinine clearance 30–80 ml/min), the recommended dose is the same as indicated above in the “Adults” section. Since in patients with severe renal failure (creatinine clearance <30 ml/min), sildenafil clearance is reduced, the use of the drug should be started with a dose of 25 mg. Depending on the drug effectiveness and tolerability, the dose can be increased to 50 and 100 mg.

Patients with liver failure: since in patients with liver failure, the clearance of sildenafil is reduced, for example, with cirrhosis, the use of the drug should be started with a dose of 25 mg. Depending on the effectiveness and tolerability, the dose can be increased to 50 and 100 mg.

Mechanism of action

Sildenafil is an oral medication that is intended to treat erectile dysfunction. The drug renews reduced erectile function by increasing blood flow to the penis in the case of sexual stimulation.

The physiological mechanism of an erection is the release of nitric oxide (NO) in the cavernous body during sexual stimulation. Released nitric oxide activates the enzyme guanylate cyclase, which stimulates an increase in cGMP. It, in turn, causes relaxation of the smooth muscles of the cavernous body, contributing to increased blood flow.

Sildenafil is a potent and selective inhibitor of cGMP-specific phosphodiesterase-5 (PDE-5) in the cavernous body, where PDE-5 is responsible for the breakdown of cGMP. The effects of sildenafil on an erection are peripheral. Sildenafil does not have a direct relaxing effect on an isolated human cavernous body. It potently enhances the relaxing effect of NO on this tissue. When the metabolic pathway NO/cGMP is activated, which occurs during sexual stimulation, inhibition of PDE-5 by sildenafil results in an increase in the level of cGMP in the cavernous body. Thus, in order for sildenafil to cause the necessary pharmacological effect, sexual excitement is necessary.

How fast does it work?

Place a tablet under the tongue and wait until it dissolves. The components enter the blood. The effect appears somewhere within 30-60 minutes. But, like all drugs of this type, sexual excitement is required. It is also necessary to take into account that the use of fatty foods can slow down the rate of active substances’ absorption in the blood. Therefore, on the day of the drug use, it is desirable to deny fatty foods.

How long does Viagra last?

The effect lasts for 5 hours. If the effect lasts longer than the specified time, you need to urgently seek the help of doctors, otherwise, this is fraught with damage to the penile tissue and irreparable loss of erection.

Side effects

In order to prevent side effects caused by Viagra, the patient is required to strictly follow all instructions and rules aimed at preventing unwanted effects. Often, the symptoms of this drug manifest themselves weakly and are due to a transient nature. Often this happens due to an increase in the recommended daily dose.

Common side effects are:

  • visual impairment;
  • eye ache;
  • a change in light perception;
  • a sensation of heat;
  • increased fatigue;
  • backache;
  • nasal congestion, infrequently – nosebleeds;
  • cough;
  • nausea, indigestion.

Symptoms that manifest themselves can clearly cause irreparable damage to your health. With a feeling of extreme malaise, you must immediately seek the help of medical professionals.

Contraindications

  • Hypersensitivity to the active substance or any other component of the drug.
  • The simultaneous use with NO donors (such as amyl nitrite) or nitrates in any form is contraindicated since sildenafil is known to affect the metabolism of NO/cGMP and potentiate the hypotensive effect of nitrates.
  • Loss of vision in one eye due to non-arterial anterior ischemic optic neuropathy, regardless of whether this pathology is associated with previous use of PDE-5 inhibitors or not.
  • The presence of the following diseases: severe liver dysfunction, arterial hypotension (blood pressure <90/50 mm Hg), recent stroke or myocardial infarction, and known hereditary degenerative diseases of the retina, such as retinitis pigmentosa since the safety of sildenafil has not been studied in patients of these subgroups.

Overdose

Side effects were similar to those noted when taking Viagra in lower doses. These studies were conducted on healthy volunteers with a single dose of the drug in doses up to 800 mg. Their frequency and severity increase. The use of sildenafil in a dose of 200 mg did not result in an increase in effectiveness but caused an increase in the number of cases of adverse reactions (headache, flushing, dizziness, dyspepsia, nasal congestion, visual impairment).

In case of overdose, if necessary, resort to the usual supportive measures. Acceleration of clearance of sildenafil during hemodialysis is unlikely due to the high degree of drug binding to plasma proteins and the excretion of sildenafil in the urine.

Compatibility with alcohol

Studies based on this combination have shown that combining Viagra with ethanol is undesirable.

In the case of abnormal consumption of alcoholic beverages, the rate of absorption of active substances in the blood slows down. Alcohol is processed by the liver, like Viagra itself – such a combination is excessively harmful to its normal functioning. Alcohol drinks have a great effect on the functioning of the heart, expanding blood vessels, and Sildenafil contributes to the blood supply to all organs. As a result, the heart needs to work twice harder.

But there are permissible norms of alcohol, the use of which will not be able to harm your health. The dose of strong drinks can be up to 50 g, the dose of drinks with low alcohol content, such as beer, wine, etc., can vary from 100 to 200 g.