What is the effect of Viagra for men? What happens if a healthy man takes Viagra? Sex prolonging drugs

Viagra is a potent drug for strengthening potency, known to almost everyone. It helps to quickly restore the functioning of the reproductive system, strengthen erections and prolong sexual intercourse, but it has a lot of contraindications and side effects that you should know about before starting to take the pills.

The principle of action of the drug is based on accelerating the production of a substance that has a direct effect on the movement of blood in the body and its filling of the cavernous bodies of the penis. It also regulates the mechanism for the outflow of blood fluid from the pelvic organs, which is why an erection will remain throughout the entire time of intimacy.

In addition, Viagra smoothes the muscles of the penis. The absence of spasms leads to greater blood flow. The vessels dilate, the phallus hardens, rises and increases significantly in size. At the same time, the pills do not have an effect on libido, that is, they do not stimulate sexual desire for a partner. Arousal should come naturally. This is the main condition for the drug to start working. If you have low libido, you will have to buy aphrodisiacs. They will increase sexual desire and only then Viagra will start working.

According to research, the medicine to a certain extent affects the sensations that a person experiences during sexual intercourse. Sex becomes intense, orgasm lasts longer and gives more pleasure. Ejaculation does not occur for a long time, but even after ejaculation, a repeated erection occurs quite quickly.

The effect of Viagra is observed over a certain period of time – up to 24 hours. The drug helps to quickly achieve a stable erection, but problems with potency remain unresolved. To get rid of erectile dysfunction, a man must undergo a comprehensive examination and take other medications along with Viagra, the main purpose of which is to restore the functioning of the reproductive system.

How to take Viagra correctly

The speed of action of the stimulant depends on the conditions of use of the tablet. If you drink it on an empty stomach, the effect will be felt after 30 minutes. After a hearty lunch or dinner, the result will appear in about an hour.

As for the duration of action, the decisive factors here are the state of the body and its sensitivity to the active component. If the patient does not have problems with the blood vessels and heart, then an erection under the influence of Viagra will last up to 8 hours. There are some men who claim that their penis remains combat-ready throughout the day.

The duration of action of Viagra is also affected by its dosage. Usually, for a normal effect, one capsule (tablet) is enough, but some macho people prefer to double the single serving. Naturally, in such cases the erection will remain for a long time. However, exceeding the dosage is fraught with serious health problems.

Optimal dosage

The effect of Viagra is noticeable only with the correct dosage, but it is different for each person. The volume of the drug taken is determined by the doctor. Typically, men with problems in bed are prescribed 100 mg. Over time, this figure is reduced to 25 mg or, conversely, increased to 150-200.

The maximum dose of the drug in the presence of pathologies of the cardiovascular system is 50 mg. It is unacceptable to correct it yourself.

Stages of action of the drug

Viagra works in stages. First, the man notices a rush of blood to the genitals. But at the same time, the penis has not yet entered into an erect state.

At the second stage, the penis becomes thicker, but it is still not ready to perform the act of phallus.

In the third stage, the phallus finally hardens. This is the final stage - absolute erection. The man is ready to enter into intimacy.

In order for the human body to go through all stages, one must take the standard dosage of the drug – 100 mg. Otherwise, the penis will become filled with blood, but will not be suitable for full sexual intimacy.

Ways to prolong the effect of Viagra

Viagra will last longer if you know a few tricks. The first secret lies in proper breathing. After taking a pill and feeling excited, under no circumstances should you hold air in your lungs. Frequent sighs can also lead to accelerated ejaculation. A fast flow of air makes the heart beat faster and the body instinctively tries to expel sperm faster.

You need to breathe according to the following pattern: inhale as deeply as possible, stop for a short time and exhale in the same way. If you focus your attention on breathing, as yogis do during meditation, then sexual intercourse becomes prolonged.

In order not to minimize the effect of Viagra, you cannot combine it with alcohol. Alcohol relaxes the muscles, and in this state ejaculation occurs very quickly. In addition, there is a double load on the cardiovascular system.

You should also not smoke after taking the pill. Nicotine has a bad effect on blood vessels and dulls the effect of the active component of the drug.

Can Viagra negatively affect men?

Viagra causes a number of health problems in the presence of the following pathologies:

tachycardia, arrhythmia, previous heart attack;
disorders of the kidneys and liver: gastritis, colitis;
anemia;
low hemoglobin.

In these cases, consultation with a doctor is required; in pursuit of pleasure, you should not forget about your own health and drink everything.

Side effects are expressed as:

weaknesses;

swelling;
allergic rash;
headaches;
nausea.

Cases in which Viagra cannot help

If a person suffers from alcoholism, then the effect of the drug on his body is minimal. In drunkards, even a double dose of Viagra is not able to cause an erection.

Similar difficulties are seen in men with hormonal imbalance. Lack of testosterone reduces libido, and lack of sexual desire is the main reason that after taking the drug the penis still does not become erect.

Video on topic

The drug "Viagra" is used to correct erectile dysfunction in men.

Important! An erection occurs only when a man is sexually aroused, and not immediately after taking the pill. The drug enhances erection by improving blood circulation in the penis area.

Diagnosis of erectile dysfunction involves a complete medical history and examination to determine possible causes and determine effective treatment. Only after this can Viagra be prescribed for correction, if it is not a consequence of a serious pathology.

Release form and composition of Viagra

The active component of the drug is sildenafil. This chemical compound prevents the uptake and utilization of nitric oxide by inhibiting the activity of the phosphodiesterase-5 enzyme.

In addition to the main component, each tablet contains:

The drug is produced in the form of bluish tablets with a slightly elongated shape and rounded edges. The blister contains from 1 to 4 tablets. Each contains 25, 50 or 100 mg of active substance. Available without a prescription.

pharmachologic effect

Sildenafil is involved in the metabolism of nitric oxide, which has a vasodilating effect.

By acting on the smooth muscle tissue of the corpus cavernosum, the drug helps to relax it. As a result of this, more blood flows through the vessels that supply blood to the male genital organs, which contributes to the occurrence of an erection.

The duration of an erection varies from half an hour to several hours, depending on the dosage.

Brief instructions for using Viagra

The drug is used for the following disorders:

Inability to complete sexual intercourse due to erectile dysfunction.
Other types of erectile dysfunction.

Take the pill one hour before sexual intercourse. Start taking 50 mg. If the effect is insufficient or absent, the dosage is increased to 100 mg per dose.

The dosage should be reduced to 25 mg if the drug is poorly tolerated. At the same time, monitor the functioning of the cardiovascular system.

The maximum dose should not exceed 100 mg per day.

Important!Viagra is not a drug and does not cure a disease such as erectile dysfunction. The drug temporarily eliminates its symptoms, causing exclusively physiological arousal.

The effect is achieved only during sexual stimulation, that is, an erection does not occur spontaneously.

Analogs of Viagra

Today, in addition to Viagra, there are many analogues on the market that have identical properties and similar composition. These include:

Levitra.
Cialis.

In addition, you can buy generics of Viagra in pharmacies, that is, drugs that contain sildenafil. There may be some discrepancy in the auxiliary components in the composition, but the active ingredient remains unchanged.

Eg:

Kamagra.
Vigrande.
Revatio.

The manufacturer of analogues, using a completely identical formula of the original active substance, may not conduct laboratory and clinical tests of the resulting drugs.

Contraindications and side effects of Viagra

Unfortunately, Viagra in the body does not always affect only the reproductive system. The side effects of the drug cause contraindications to its use.
The use of Viagra is contraindicated:

Men under 18 years of age.
With parallel intake of nitrates. If a man takes any medicine of this group according to indications, then the drug cannot be prescribed.
Combined use of original and generic drugs. This may lead to an overdose.

There are a number of diseases for which taking Viagra is possible, but should only be done under the strict supervision of a specialist. The drug is prescribed with caution in the presence of such pathologies:

Whether to prescribe the drug or not should be determined by the doctor, based on an analysis of the man’s general health, taking into account the concurrent drug therapy, as well as existing diseases.

All side effects can be divided into several groups. They are divided according to the frequency of occurrence detected during clinical trials:

Very common:

hyperemia (redness) of the face caused by a rush of blood;

Frequently occurring:

(increased heart rate);
skin rashes;
visual impairment. The drug can provoke: achromatopsia, hypersensitivity to light and blurred vision;
nasal congestion;
sleep disturbance;
phenomena.

Isolated cases of manifestation:

redness (injection) of the sclera;
from the cardiovascular system the following were observed: tachyarrhythmia, collapse (significant drop in blood pressure) and;
prostate dysfunction;

Pharmacology

Sildenafil is a potent selective inhibitor of cGMP-specific phosphodiesterase type 5 (PDE5).

The physiological mechanism of erection is associated with the release of nitric oxide (NO) in the corpus cavernosum during sexual stimulation. This, in turn, leads to an increase in cGMP levels, subsequent relaxation of the smooth muscle tissue of the corpus cavernosum and increased blood flow.

Sildenafil does not have a direct relaxant effect on the isolated corpus cavernosum in humans, but enhances the effect of NO by inhibiting PDE5, which is responsible for the breakdown of cGMP.

Sildenafil is selective for PDE5 in vitro, its activity against PDE5 exceeds that of other known phosphodiesterase isoenzymes: PDE6 - 10 times; PDE1 - more than 80 times; PDE2, PDE4, PDE7-PDE11 - more than 700 times. Sildenafil is 4000 times more selective for PDE5 compared to PDE3, which is of utmost importance since PDE3 is one of the key enzymes in the regulation of myocardial contractility.

A prerequisite for the effectiveness of sildenafil is sexual stimulation.

Clinical data

Cardiac research

The use of sildenafil in doses up to 100 mg did not lead to clinically significant ECG changes in healthy volunteers. The maximum decrease in systolic blood pressure in the supine position after taking sildenafil at a dose of 100 mg was 8.3 mm Hg, and diastolic blood pressure was 5.3 mm Hg. A more pronounced, but also transient effect on blood pressure was observed in patients taking nitrates.

In a study of the hemodynamic effect of sildenafil at a single dose of 100 mg in 14 patients with severe coronary artery disease (more than 70% of patients had stenosis of at least one coronary artery), resting systolic and diastolic blood pressure decreased by 7% and 6%, respectively. , and pulmonary systolic pressure decreased by 9%. Sildenafil did not affect cardiac output or impair blood flow in stenotic coronary arteries, and also resulted in an increase (by approximately 13%) in adenosine-induced coronary blood flow in both stenotic and intact coronary arteries.

In a double-blind, placebo-controlled study, 144 patients with erectile dysfunction and stable angina taking antianginal drugs (except nitrates) exercised until their angina symptoms improved. The duration of the exercise was significantly longer (19.9 seconds; 0.9-38.9 seconds) in patients taking sildenafil in a single dose of 100 mg compared to patients receiving placebo.

A randomized, double-blind, placebo-controlled study examined the effect of varying the dose of sildenafil (up to 100 mg) in men (n=568) with erectile dysfunction and hypertension taking more than two antihypertensive medications. Sildenafil improved erections in 71% of men compared to 18% in the placebo group. The incidence of adverse effects was comparable to that in other patient groups, as well as in individuals taking more than three antihypertensive drugs.

Visual impairment studies

In some patients, 1 hour after taking sildenafil at a dose of 100 mg, the Farnsworth-Munsell 100 test revealed a mild and transient impairment in the ability to distinguish shades of color (blue/green). 2 hours after taking the drug, these changes were absent. Color vision impairment is thought to be caused by inhibition of PDE6, which is involved in light transmission in the retina. Sildenafil had no effect on visual acuity, contrast perception, electroretinogram, intraocular pressure, or pupil diameter.

In a placebo-controlled crossover study of patients with proven early-onset macular degeneration (n=9), sildenafil in a single dose of 100 mg was well tolerated. There were no clinically significant changes in vision assessed by specific visual tests (visual acuity, Amsler grating, color perception, color transmission simulation, Humphrey perimeter, and photostress).

Efficiency

The effectiveness and safety of sildenafil was assessed in 21 randomized, double-blind, placebo-controlled studies lasting up to 6 months in 3,000 patients aged 19 to 87 with erectile dysfunction of various etiologies (organic, psychogenic or mixed). The effectiveness of the drug was assessed globally using an erection diary, the International Index of Erectile Function (a validated questionnaire about the state of sexual function) and a partner interview. The effectiveness of sildenafil, defined as the ability to achieve and maintain an erection sufficient for satisfactory sexual intercourse, has been demonstrated in all studies conducted and was confirmed in long-term studies lasting 1 year. In fixed-dose studies, the proportion of patients reporting that therapy improved their erections was: 62% (25 mg sildenafil dose), 74% (50 mg sildenafil dose), and 82% (100 mg sildenafil dose), compared with 25 % in the placebo group. Analysis of the International Index of Erectile Function showed that in addition to improving erection, treatment with sildenafil also increased the quality of orgasm, achieved satisfaction from sexual intercourse and overall satisfaction.

According to the pooled data, among patients who reported improved erections with sildenafil treatment, 59% of patients with diabetes, 43% of patients who had undergone radical prostatectomy and 83% of patients with spinal cord injury (compared with 16%, 15% and 12% in the placebo group) respectively).

Pharmacokinetics

Suction

After oral administration, sildenafil is rapidly absorbed. Absolute bioavailability averages 40% (25-63%). In vitro, sildenafil at a concentration of approximately 1.7 ng/ml (3.5 nM) inhibits human PDE5 by 50%. After a single dose of 100 mg of the drug orally, the average Cmax of free sildenafil is 18 ng/ml (38 nM) and is achieved when taken on an empty stomach within an average of 60 minutes (30-120 minutes).

When taken in combination with fatty foods, the rate of absorption is reduced; Tmax increases by 60 minutes, and Cmax decreases by an average of 29%. However, the degree of absorption does not change significantly (AUC decreases by 11%).

Distribution

Vd of sildenafil at steady state averages 105 liters.

The binding of sildenafil and its main circulating N-desmethyl metabolite to plasma proteins is about 96% and is independent of the total concentration of sildenafil. Less than 0.0002% of the dose (average 188 ng) was found in semen 90 minutes after taking the drug.

Metabolism

Sildenafil is metabolized mainly in the liver under the influence of isoenzymes CYP3A4 (major pathway) and CYP2C9 (minor pathway).

The main circulating active metabolite, which is formed as a result of N-demethylation of sildenafil, undergoes further metabolism.

In terms of selectivity of action on PDE, the metabolite is comparable to sildenafil, and its activity against PDE5 in vitro is approximately 50% of the activity of sildenafil.

The concentration of the metabolite in the blood plasma is approximately 40% of that of sildenafil.

The N-demethyl metabolite undergoes further metabolism; its T1/2 is about 4 hours.

Removal

The total clearance of sildenafil from the body is 41 l/h, and the final half-life is 3-5 hours. After oral administration, sildenafil is excreted in the form of metabolites, mainly in feces (approximately 80% of the dose) and to a lesser extent in urine (approximately 13% of the dose).

Pharmacokinetics in special clinical situations

In healthy elderly people (over 65 years of age), the clearance of sildenafil is reduced, and the concentration of the free active substance in plasma is approximately 40% higher than its concentration in young (18-45 years of age) patients. Age does not have a clinically significant effect on the incidence of side effects.

In case of mild (creatinine clearance 50-80 ml/min) and moderate (creatinine clearance 30-49 ml/min) renal failure, the pharmacokinetic parameters of sildenafil do not change after a single oral dose of 50 mg.

In severe renal failure (creatinine clearance ≤30 ml/min), the clearance of sildenafil is reduced, which leads to an approximately twofold increase in AUC (100%) and C max (88%) compared with those with normal renal function in patients of the same age group .

In patients with liver cirrhosis (Child-Pugh class A and B), the clearance of sildenafil is reduced, which leads to an increase in AUC (84%) and Cmax (47%) compared with those with normal liver function in patients of the same age groups. The pharmacokinetics of sildenafil in patients with severe hepatic impairment (Child-Pugh class C) has not been studied.

Release form

Blue, diamond-shaped, slightly biconvex, film-coated tablets with cut and rounded edges, debossed with "Pfizer" on one side and "VGR 25" on the other.

Excipients: microcrystalline cellulose - 78.291 mg, calcium hydrogen phosphate - 26.097 mg, croscarmellose sodium - 7.5 mg, magnesium stearate - 3 mg.

Film shell composition*: opadry blue OY-LS-20921 (hypromellose, lactose, triacetin, titanium dioxide (E171), aluminum varnish based on indigo carmine (E132)) - 3.75 mg and opadry transparent YS-2-19114-A (hypromellose, triacetin) - 1.125 mg.

1 PC. - blisters (1) - cardboard packs with first opening control.

* up to 30 µg/g of vanillin and/or biotin can be added to the film coating; in this case, the content of one or both components in the film coating will be up to 0.75 μg for a dosage of 25 mg.

Dosage

The drug is taken orally.

In elderly patients, no dose adjustment is required.

For mild to moderate renal failure (CR 30-80 ml/min), no dose adjustment is required; for severe renal failure (CR<30 мл/мин) дозу силденафила следует снизить до 25 мг.

Combined use with other drugs

When used together with ritonavir, the maximum single dose of Viagra ® should not exceed 25 mg, the frequency of use is 1 time every 48 hours.

When used together with inhibitors of the CYP3A4 isoenzyme (erythromycin, saquinavir, ketoconazole, itraconazole), the initial dose of Viagra ® should be 25 mg.

To minimize the risk of postural hypotension in patients taking alpha-blockers, Viagra should be started only after hemodynamic stabilization has been achieved in these patients. The advisability of reducing the initial dose of sildenafil should be considered.

Overdose

With a single dose of the drug up to 800 mg, adverse events were comparable to those when taking sildenafil in lower doses, but were more common.

Treatment: symptomatic therapy. Hemodialysis does not accelerate the clearance of sildenafil, because the latter actively binds to plasma proteins and is not excreted in the urine.

Interaction

The effect of other drugs on the metabolism of sildenafil

The metabolism of sildenafil occurs mainly in the liver under the influence of the isoenzymes CYP3A4 (the main pathway) and CYP2C9, therefore inhibitors of these isoenzymes can reduce the clearance of sildenafil, and inducers, accordingly, increase the clearance of sildenafil.

With simultaneous use of CYP3A4 inhibitors (such as ketoconazole, erythromycin, cimetidine), a decrease in the clearance of sildenafil was observed.

Cimetidine (at a dose of 800 mg), which is a nonspecific inhibitor of CYP3A4, when taken simultaneously with sildenafil (at a dose of 50 mg), causes an increase in plasma concentrations of sildenafil by 56%.

A single dose of sildenafil in a dose of 100 mg simultaneously with erythromycin, a specific inhibitor of CYP3A4 (when taking erythromycin 500 mg 2 times a day for 5 days), while achieving a constant concentration of erythromycin in the blood, leads to an increase in the AUC of sildenafil by 182%.

With the simultaneous use of sildenafil (single dose of 100 mg) and saquinavir (1200 mg 3 times / day), which is both an HIV protease inhibitor and a CYP3A4 inhibitor, while achieving a constant concentration of saquinavir in the blood, Cmax of sildenafil in the blood increased by 140% and AUC increased by 210%. Sildenafil had no effect on the pharmacokinetic parameters of saquinavir.

Stronger inhibitors of the CYP3A4 isoenzyme, such as ketoconazole or itraconazole, may cause more pronounced changes in the pharmacokinetics of sildenafil.

The simultaneous use of sildenafil (single dose of 100 mg) and ritonavir (500 mg 2 times / day), which is an HIV protease inhibitor and a strong inhibitor of cytochrome P450 isoenzymes, while achieving a constant concentration of ritonavir in the blood leads to an increase in Cmax of sildenafil by 300% (4 times), and AUC by 1000% (11 times). After 24 hours, the concentration of sildenafil in the blood plasma was approximately 200 ng/ml (with a single dose of sildenafil alone - 5 ng/ml).

A single dose of an antacid (magnesium hydroxide/aluminum hydroxide) does not affect the bioavailability of sildenafil.

In studies involving healthy volunteers, with the simultaneous use of an endothelin receptor antagonist, bosentan (an inducer of the isoenzyme CYP3A4 (moderate), CYP2C9 and possibly CYP2C19) at steady state concentration (125 mg 2 times / day) and sildenafil at equilibrium concentration (80 mg 3 times /day) there was a decrease in AUC and Cmax of sildenafil by 62.6% and 52.4%, respectively. Sildenafil increased the AUC and Cmax of bosentan by 49.8% and 42%, respectively. It is assumed that the simultaneous use of sildenafil with potent inducers of the CYP3A4 isoenzyme, such as rifampicin, may lead to a greater decrease in the concentration of sildenafil in the blood plasma.

Inhibitors of the CYP2C9 isoenzyme (such as tolbutamide, warfarin), the CYP2D6 isoenzyme (such as selective serotonin reuptake inhibitors, tricyclic antidepressants), thiazides and thiazide-like diuretics, ACE inhibitors and calcium antagonists do not affect the pharmacokinetics of sildenafil.

Co-administration of azithromycin (500 mg/day for 3 days) has no effect on the AUC, Cmax, Tmax, elimination rate constant and T1/2 of sildenafil or its main circulating metabolite.

Effect of sildenafil on other drugs

Sildenafil is a weak inhibitor of isoenzymes of the cytochrome P450 system - 1A2, 2C9, 2C19, 2D6, 2E1 and 3A4 (IK 50 >150 µmol). When sildenafil is used at recommended doses, its Cmax is approximately 1 µmol, so it is unlikely that sildenafil could affect the clearance of substrates of these isoenzymes.

Sildenafil enhances the hypotensive effect of nitrates both with long-term use and when used for acute indications. In this regard, the use of sildenafil in combination with nitrates or nitric oxide donors is contraindicated.

When co-administering the alpha-blocker doxazosin (4 mg and 8 mg) and sildenafil (25 mg, 50 mg and 100 mg) in patients with benign prostatic hyperplasia with stable hemodynamics, the average additional reduction in systolic/diastolic blood pressure in the supine position was 7 /7 mm Hg, 9/5 mm Hg. and 8/4 mm Hg. respectively, and in a standing position - 6/6 mm Hg, 11/4 mm Hg. and 4/5 mm Hg. respectively. Rare cases of symptomatic postural hypotension, manifested in the form of dizziness (without fainting), have been reported in such patients. In selected sensitive patients receiving alpha-blockers, concomitant use of sildenafil may lead to symptomatic hypotension.

There were no signs of significant interactions between sildenafil and tolbutamide (250 mg) or warfarin (40 mg), which are metabolized by CYP2C9.

Sildenafil at a dose of 100 mg does not affect the pharmacokinetic parameters of HIV protease inhibitors at constant concentrations in the blood, such as saquinavir and ritonavir, which are also CYP3A4 substrates.

Co-administration of sildenafil at steady state (80 mg 3 times/day) leads to an increase in the AUC and Cmax of bosentan (125 mg 2 times/day) by 49.8% and 42%, respectively.

Sildenafil at a dose of 50 mg does not cause an additional increase in bleeding time when taking acetylsalicylic acid at a dose of 150 mg.

Sildenafil at a dose of 50 mg does not enhance the hypotensive effect of ethanol in healthy volunteers with a maximum ethanol blood level of 0.08% (80 mg/dL) on average.

In patients with arterial hypertension, there were no signs of interaction between sildenafil (at a dose of 100 mg) and amlodipine. The average additional reduction in blood pressure in the supine position is 8 mmHg. (systolic) and 7 mm Hg. (diastolic).

The use of sildenafil in combination with antihypertensive drugs does not lead to additional side effects.

Side effects

The most common side effects were headache and flushing.

Side effects are usually mild or moderate and transient.

Fixed-dose studies have found that the incidence of some adverse events increases with increasing dose.

The frequency of adverse reactions is determined as follows:

From the immune system: rarely - hypersensitivity reactions (including skin rash), allergic reactions.

From the organ of vision: often - blurred vision, blurred vision, cyanopsia; uncommon - eye pain, photophobia, photopsia, chromatopsia, redness of the eyes/scleral injections, changes in the brightness of light perception, mydriasis, conjunctivitis, hemorrhage in the eye tissue, cataracts, disruption of the lacrimal apparatus; rarely - swelling of the eyelids and adjacent tissues, a feeling of dryness in the eyes, the presence of rainbow circles in the field of vision around the light source, increased eye fatigue, seeing objects in yellow (xanthopsia), seeing objects in red (erythropsia), conjunctival hyperemia, irritation of the mucous membrane eye, discomfort in the eyes; frequency unknown - non-arteritic anterior ischemic optic neuropathy (NAIOP), retinal vein occlusion, visual field defect, diplopia*, temporary loss of vision or decreased visual acuity, increased intraocular pressure, retinal edema, retinal vascular disease, vitreous detachment/vitreal traction.

On the part of the hearing organ: uncommon - sudden decrease or loss of hearing, tinnitus, ear pain.

From the cardiovascular system: often - “hot flashes”; uncommon - tachycardia, palpitations, decreased blood pressure, increased heart rate, unstable angina, AV block, myocardial ischemia, cerebral vascular thrombosis, cardiac arrest, heart failure, abnormal ECG readings, cardiomyopathy; rarely - atrial fibrillation.

From the hematopoietic system: infrequently - anemia, leukopenia.

From the side of metabolism and nutrition: infrequently - a feeling of thirst, edema, gout, uncompensated diabetes mellitus, hyperglycemia, peripheral edema, hyperuricemia, hypoglycemia, hypernatremia.

From the respiratory system: often - nasal congestion; uncommon - nosebleeds, rhinitis, asthma, dyspnea, laryngitis, pharyngitis, sinusitis, bronchitis, increased volume of sputum, increased cough; rarely - a feeling of tightness in the throat, dryness of the nasal mucosa, swelling of the nasal mucosa.

From the digestive system: often - nausea, dyspepsia; uncommon - gastroesophageal reflux disease, vomiting, abdominal pain, dry mouth, glossitis, gingivitis, colitis, dysphagia, gastritis, gastroenteritis, esophagitis, stomatitis, abnormal liver function tests, rectal bleeding; rarely - hypoesthesia of the oral mucosa.

From the musculoskeletal system: often - back pain; uncommon - myalgia, pain in the limbs, arthritis, arthrosis, tendon rupture, tenosynovitis, bone pain, myasthenia gravis, synovitis.

From the genitourinary system: infrequently - cystitis, nocturia, breast enlargement, urinary incontinence, hematuria, ejaculation disorders, genital swelling, anorgasmia, hematospermia, damage to penile tissue; rarely - prolonged erection and/or priapism.

From the central and peripheral nervous system: very often - headache; often - dizziness; uncommon - drowsiness, migraine, ataxia, hypertonicity, neuralgia, neuropathy, paresthesia, tremor, vertigo, symptoms of depression, insomnia, unusual dreams, increased reflexes, hypoesthesia; rarely - convulsions*, repeated convulsions*, fainting.

From the skin and subcutaneous tissues: uncommon - skin rash, urticaria, herpes simplex, itching, increased sweating, skin ulceration, contact dermatitis, exfoliative dermatitis; frequency unknown - Stevens-Johnson syndrome, toxic epidermal necrolysis.

Other: infrequently - feeling of heat, swelling of the face, photosensitivity reactions, shock, asthenia, increased fatigue, pain of various localizations, chills, accidental falls, pain in the chest, accidental injuries; rarely - irritability.

* Side effects identified during post-marketing studies.

During post-marketing use of sildenafil for the treatment of erectile dysfunction, adverse events such as severe cardiovascular complications (including myocardial infarction, unstable angina, sudden cardiac death, ventricular arrhythmia, hemorrhagic stroke, transient ischemic attack, hypertension and hypotension) have been reported ), which had a temporary association with the use of sildenafil. Most of these patients, but not all of them, had risk factors for cardiovascular complications. Many of these adverse events occurred shortly after sexual activity, and some of them occurred after taking sildenafil without subsequent sexual activity. It is not possible to establish a direct connection between the observed adverse events and these or other factors.

Visual impairment

In rare cases, during post-registration use of all PDE5 inhibitors, incl. sildenafil, non-arteritic anterior ischemic optic neuropathy (NAIOPN), a rare disease and cause of decreased or loss of vision, has been reported. Most of these patients had risk factors, including decreased papilledema/disc ratio (“congestive disc”), age over 50 years, diabetes mellitus, hypertension, coronary artery disease, hyperlipidemia, and smoking. An observational study assessed whether recent use of the PDE5 inhibitor class of drugs was associated with acute onset of NPINSID. Results indicate an approximately 2-fold increase in the risk of NPINSID within 5 half-lives of PDE5 inhibitor use. According to the published literature, the annual incidence of NPINSID is 2.5-11.8 cases per 100,000 men aged >50 years in the general population. In case of sudden loss of vision, patients should be advised to stop sildenafil therapy and consult a doctor immediately. Individuals who have already had a case of NPIND have an increased risk of recurrent NPIND. Therefore, the physician should discuss this risk with such patients, as well as discuss with them the potential for adverse effects from PDE5 inhibitors. PDE5 inhibitors, incl. sildenafil should be used with caution in such patients and only in situations where the expected benefit outweighs the risk.

When using the drug Viagra ® in doses exceeding the recommended ones, adverse events were similar to those noted above, but usually occurred more often.

Indications

treatment of erectile dysfunction, characterized by the inability to achieve or maintain a penile erection sufficient for satisfactory sexual intercourse.

Sildenafil is only effective during sexual stimulation.

Contraindications

use in patients receiving continuous or intermittent nitric oxide donors, organic nitrates or nitrites in any form, since sildenafil enhances the hypotensive effect of nitrates;
simultaneous use of the drug with other drugs for the treatment of erectile dysfunction (the safety and effectiveness of combination therapy has not been studied);
children and adolescents up to 18 years of age;
women;
hypersensitivity to sildenafil or to any component of the drug.

The drug should be used with caution in case of anatomical deformation of the penis (including angulation, cavernous fibrosis or Peyronie's disease); for diseases that predispose to the development of priapism (such as sickle cell anemia, multiple myeloma, leukemia, thrombocytopenia); for diseases accompanied by bleeding; with exacerbation of peptic ulcer of the stomach and duodenum; hereditary retinitis pigmentosa; heart failure, unstable angina, myocardial infarction in the last 6 months, stroke, severe life-threatening arrhythmias, arterial hypertension (BP more than 170/100 mmHg) or hypotension (BP less than 90/50 mmHg) .

Features of application

Use during pregnancy and breastfeeding

According to its registered indication, the drug is not intended for use in women.

Use for liver dysfunction

Since the elimination of sildenafil is impaired in patients with liver damage (for example, cirrhosis), the dose of the drug should be reduced to 25 mg.

Use for renal impairment

Use in children

The drug is not intended for use in children and adolescents under 18 years of age.

special instructions

To diagnose erectile dysfunction, determine its possible causes and select adequate treatment, it is necessary to obtain a complete medical history and conduct a thorough physical examination. Treatments for erectile dysfunction should be used with caution in patients with anatomical deformation of the penis (angulation, cavernous fibrosis, Peyronie's disease), or in patients with risk factors for the development of priapism (sickle cell anemia, multiple myeloma, leukemia).

During post-marketing studies, cases of prolonged erection and priapism have been reported. If an erection persists for more than 4 hours, the patient should immediately seek medical help. If treatment for priapism is not carried out immediately, it can lead to damage to the tissue of the penis and irreversible loss of potency.

Medicines intended to treat erectile dysfunction should not be prescribed to men for whom sexual activity is undesirable.

Sexual activity poses a certain risk in the presence of heart disease, so before starting any therapy for erectile dysfunction, the doctor should refer the patient for an examination of the condition of the cardiovascular system. Sexual activity is not advisable in patients with heart failure, unstable angina, myocardial infarction or stroke in the last 6 months, life-threatening arrhythmias, arterial hypertension (BP >170/100 mm Hg) or hypotension (BP<90/50 мм рт.ст.). В клинических исследованиях показано отсутствие различий в частоте развития инфаркта миокарда (1.1 на 100 человек в год) или частоте смертности от сердечно-сосудистых заболеваний (0.3 на 100 человек в год) у пациентов, получавших препарат Виагра ® , по сравнению с пациентами, получавшими плацебо.

Cardiovascular complications

During post-marketing use of sildenafil for the treatment of erectile dysfunction, adverse events such as serious cardiovascular complications (including myocardial infarction, unstable angina, sudden cardiac death, ventricular arrhythmia, hemorrhagic stroke, transient ischemic attack, arterial hypertension and hypotension), which had a temporary association with the use of sildenafil. Most of these patients, but not all of them, had risk factors for cardiovascular complications. Many of these adverse events occurred shortly after sexual activity, and some of them occurred after taking sildenafil without subsequent sexual activity. It is not possible to establish a direct connection between the observed adverse events and these or other factors.

Hypotension

Sildenafil has a systemic vasodilating effect, leading to a transient decrease in blood pressure, which is not a clinically significant effect and does not lead to any consequences in most patients. However, before prescribing Viagra ®, the doctor must carefully assess the risk of possible undesirable manifestations of the vasodilating effect in patients with relevant diseases, especially against the background of sexual activity. Increased susceptibility to vasodilators is observed in patients with obstruction of the left ventricular outflow tract (aortic stenosis, hypertrophic obstructive cardiomyopathy), as well as with the rare syndrome of multiple system atrophy, manifested by severe dysregulation of blood pressure from the autonomic nervous system.

Since concomitant use of sildenafil and alpha-blockers may lead to symptomatic hypotension in selected sensitive patients, Viagra ® should be administered with caution to patients taking alpha-blockers. To minimize the risk of developing postural hypotension in patients taking alpha-blockers, Viagra should be started only after hemodynamic parameters have stabilized in these patients. You should also consider the advisability of reducing the initial dose of Viagra ®. Patients should be informed of what actions to take if symptoms of postural hypotension occur.

Visual impairment

A small number of patients with hereditary retinitis pigmentosa have genetically determined dysfunction of retinal phosphodiesterases. There is no information on the safety of Viagra ® in patients with retinitis pigmentosa, so sildenafil should be used with caution.

Hearing impairment

Some post-marketing and clinical studies have reported cases of sudden deterioration or loss of hearing associated with the use of all PDE5 inhibitors, including sildenafil. Most of these patients had risk factors for sudden deterioration or loss of hearing. A cause-and-effect relationship between the use of PDE5 inhibitors and sudden hearing loss or deterioration has not been established. In case of sudden deterioration of hearing or hearing loss while taking sildenafil, the patient should immediately consult a doctor.

Bleeding

Sildenafil enhances the antiplatelet effect of sodium nitroprusside, a nitric oxide donor, on human platelets in vitro. There are no data on the safety of sildenafil in patients with a tendency to bleeding or exacerbation of gastric and duodenal ulcers, so Viagra ® should be used with caution in these patients. The incidence of epistaxis in patients with pulmonary hypertension associated with diffuse connective tissue diseases was higher (sildenafil 12.9%, placebo 0%) than in patients with primary pulmonary hypertension (sildenafil 3%, placebo 2.4%). In patients receiving sildenafil in combination with a vitamin K antagonist, the incidence of epistaxis was higher (8.8%) than in patients not taking a vitamin K antagonist (1.7%).

Use in conjunction with other means of treating erectile dysfunction

The safety and effectiveness of Viagra ® in combination with other PDE5 inhibitors or other drugs for the treatment of pulmonary hypertension containing sildenafil (for example, Revatio ®) or other drugs for the treatment of erectile dysfunction, therefore the use of such combinations is not recommended.

Impact on the ability to drive vehicles and operate machinery

While taking Viagra ®, no negative effects on the ability to drive a car or use other technical equipment were observed. However, since when taking the drug, a decrease in blood pressure, the development of chromatopsia, and blurred vision are possible, you should be careful about the individual effect of the drug in these situations, especially at the beginning of treatment and when changing the dosage regimen.

How long does Viagra last, what effect does the pill have on a man’s body, what is the principle of its action? The pharmacological drug helps in the fight against potency, restores male strength and prolongs sexual intercourse. Regular use of the product normalizes the natural mechanism of erection, increases sexual desire, and guarantees new sensations.

What is Viagra

Viagra is a clinically proven medicine, its main purpose is to eliminate erectile dysfunction. The product is suitable for both male and female bodies. A generic of Indian origin with a long history and a lot of positive reviews, it quickly eliminates sexual disorders, including impotence. How much and how does Viagra work? The action and effectiveness of the drug are aimed at achieving and strengthening an erection in men, maintaining it during sexual arousal and intercourse.

The drug is based on the substance sildenafil. The active component is responsible for the natural process of erection. Sildenafil affects the quality of ejaculation, making it longer and brighter. Attention: the effect of the medication begins only in case of sexual arousal. Viagra affects natural processes in the body, enhancing erection without additional stimulation.

How does Viagra work for men?

The mechanism of action of the pill is to increase blood circulation at the base of the penis. The process allows you to launch natural mechanisms for the appearance and improvement of an erection in a man. Viagra is intended to enhance the natural occurrence of arousal and sexual stimulation. The presented properties make the drug in demand and popular. Viagra Soft is not a general stimulant that affects exclusively male libido. The tablet increases blood flow in the cavernous body of the penis, due to which a natural erection develops.

How long does it take to work?

How quickly does Viagra work and what affects it? After taking the tablet, the active component begins to spread through the systemic bloodstream. The maximum peak of its activity is recorded after 30-40 minutes. If a person has taken alcohol or consumed a considerable amount of fatty food the day before, the specified time period increases. The peak effect of the drug is recorded no earlier than after 1.5 hours. It is recommended to take the tablet on an empty stomach - this will enhance its effect. How fast the result will be and how long it will last depends on the man’s body.

How long does it last?

According to the developer, the optimal duration of action of Viagra is 4-5 hours. The working time of the medicine is influenced by a number of internal factors, including the state of the male reproductive system. How long does Viagra last and how to influence this process? No doctor can give a definite answer to the question of how long the effect lasts. Each case is considered individually.

Repeated studies have shown that the effect directly depends on the body’s sensitivity to the components of the drug. The duration of action of Viagra is determined by a man’s physique, his weight category, and the functioning of the gastrointestinal tract. According to patients, the duration of exposure is about 4 hours or more. Some men experienced a longer effect that lasted for a long time. How long Viagra lasts and how long the pill will “work” depends solely on the specific male body.

How much Viagra to take for lasting effect

The drug is available in two dosages: 50 and 100 mg. An experienced specialist will help determine the appropriate dose of the substance. If the prescribed amount of medication does not allow you to achieve the desired result, this issue should be discussed with your doctor. For a healthy body, it is appropriate to use the tablet no more than once a day at a dosage of 50 mg. In case of severe erectile dysfunction, especially after 65 years, it is recommended to take 25 mg of the medicine; the person cannot be given more. The effect of Viagra lasts for 4 hours, provided the dose is taken correctly.

Side effects

It is recommended to buy the product in specialized pharmacies. This guarantees safety and reduces the likelihood of adverse reactions. Wanting to quickly restore male potency, representatives of the stronger half of humanity violate the basic principles of taking medication. This negatively affects their well-being, causing:

disorders of the gastrointestinal tract (nausea, vomiting);
prolonged headache;
acute rhinitis;
damage to the penis;
allergic reaction of varying intensity;
deterioration in general health.

Adhering to the basic principles of administration, following the given dosage and taking into account the expiration date will help to avoid adverse reactions. If discomfort, general malaise, or additional symptoms develop, the medication must be stopped. If the condition does not improve, experts recommend seeking help from a medical facility.

Contraindications

Each drug has contraindications for use. This is due to the constituent components, as well as the effect of the drug itself. The use of male and female Viagra is prohibited if you have the following deviations:

diseases of the heart and blood vessels;
anemia (anemia);
diabetes mellitus;
deformations of the genital organs (anatomical feature);
leukemia;
hypersensitivity to the active components of the drug.

A worthy replacement for Viagra are Levitra tablets; they differ in price and have a less pronounced effect. However, their use is not recommended for the contraindications described above. To obtain a positive result, including preventing adverse reactions, the medication is taken in accordance with the doctor’s recommendations.

Video

It is difficult to find a person who knows nothing about the drug Viagra. Sometimes the drug acts as a panacea for relationships, albeit with a risk to the heart and the possibility of addiction. Small blue tablets do impossible things to a man in the sexual sphere, increasing his self-esteem and value in the eyes of his beloved.

But many people have long been wondering: what will happen if a girl takes Viagra? Will an effect identical to that which the drug has on the male body appear, or will simply nothing happen? You will find answers to these questions in the article, but first let's talk about Viagra.

What is the drug?

Viagra is a very effective drug that is mainly prescribed for the treatment of erectile dysfunction. The action of Viagra is achieved by activating additional blood flow to the man's penis, which strengthens and prolongs the erection state, contributing to increased orgasmic sensations. Each tablet contains from 25 to 100 mg of sildenafil.

A blister can contain from one to twelve tablets. The drug is positioned as a salvation for sexual impotence, and it is rare that a man needs a prescription. The need for the drug arises unexpectedly and most often at night, which is noticed even by pharmacy workers. Sildenafil works by blocking a chemical that stimulates blood flow from the penis. Thus, blood circulation increases and the man gets a confident erection. In an excited state, the brain sends nerve impulses to the penis. Completion of sexual intercourse causes the muscles to contract and block the amount of blood flowing to the organ.

From the history

At first, the drug was created for a completely ordinary purpose - to treat heart diseases. But during clinical trials, a “side effect” was discovered, which later became the main one.

Most men who regularly take the drug believe that Viagra itself causes an erection, but in reality this is not entirely true. All the same, all basic instincts are under the control of the brain, and without sexual arousal it is very difficult to get an erection. And the principle of action of Viagra is based on the blockade of an enzyme that interferes with the production of chemicals that stimulate the male sex glands. After taking the pill, nitric oxide is released in the tissues of the penis. At the same time, smooth muscles relax and blood flow increases. Thus, the erection will be strong and long, and sexual emotions will become brighter. In healthy men, the half-life is about four hours, but if the patient has liver or kidney failure, then this time period increases.

The effect of the drug on the male body

The pharmaceutical company Pfizer tested a new drug on volunteers in 1992.

Many people liked the result, although it had little effect on the condition of the heart muscle. Viagra began to be used as an independent drug only six years later. As mentioned above, the drug is officially prescribed for the treatment of erectile dysfunction, but how exactly to classify this condition? It is often defined as a pathology with decreased erection quality as the main symptom. More often, such symptoms are typical for men aged forty years and older. By the way, this diagnosis is spreading both in Russia and abroad. In Massachusetts, more than half of men have erection problems. In Russia, the presence of such pathologies is explained by smoking low-quality tobacco, alcoholism and accumulating fatigue at work. The word "impotence" is used with caution, as it is equated to the complete absence of an erection. If you have erectile dysfunction and take Viagra, it is not recommended to drink alcohol, as they enhance each other's effects. The effect of Viagra is slowed down by fatty foods. And if a man is over 65 years old, the drug is eliminated more slowly and circulates in the blood for a long time. For this category of representatives of the stronger sex, it is possible to take only a small dose of the drug.

Contraindications

The drug should be used only after a doctor's prescription. It is easy to take and very effective. But there are also contraindications. Firstly, the doctor must prescribe not only the drug itself, but also its dosage. The drug is prohibited if you are simultaneously taking medications to treat angina pectoris. The thing is that they contain nitrates, donors of nitric oxide, so blood pressure drops to a critical level. The drug should not be taken if there is an increased reaction to the components in the composition, allergies, swelling or shortness of breath. Viagra can be used with caution in case of deformation of the penis, peptic ulcer, arrhythmia or stroke.

The effect of Viagra may be accompanied by a painful erection, and this can last for 4 hours and will require medical intervention. Even death can occur: according to statistics, many men die from cardiac arrest and some of them from myocardial infarction. No one was able to blame the manufacturing company for the death, since the instructions set out a number of contraindications and the drug is officially available with a prescription.

So, we looked at the features of this well-known medicine. Now let's come to the answer to the main question that interests us - what will happen if a girl takes Viagra?

For women, children and teenagers

The drug is contraindicated for these groups of people. At least that's what was thought before. If we think logically, then at least until the age of 18, teenagers should not have problems with erections. If a healthy man takes Viagra and observes an improvement in his erection, then most likely he had hidden problems. American scientists conducted research trying to find out what would happen if a girl took Viagra. The results were very interesting: it turned out that the drug helps women who have problems with orgasm, increasing their libido. The effect of this medicine on a woman was clearly shown in the TV series “Sex and the City,” where one of the heroines, Samantha Jones, voluntarily conducted a test on herself. According to the authors, she became “the first woman in space.” The drug stimulates blood flow to the genitals, increases the sensitivity of the clitoris and, accordingly, the brightness of orgasm. So in the USA, doctors prescribe Viagra to the fair sex, citing the fact that this improves the quality of sex. But it should be noted that long-term trials have not been conducted on women and it is not possible to identify side effects. There was no precedent for doctors to find out what Viagra would mean for girls, in particular on their future ability to motherhood. Most often, taking a drug is a spontaneous, thoughtless and risky action. The girl dreams of enchanting sex, although the drug itself cannot help her with this.

conclusions

So, the drug increases the level of sex hormones in the blood, and with it libido. Sensitivity to stimulation also increases rapidly. The woman is ready for a brighter orgasm, which is especially valuable during hysterectomy and menopause. Most often, men take their passion for such drugs to heart and anxiously ask doctors what will happen if a girl takes Viagra? Only a man who is not confident in his strength and wants to play it safe will react to such a trend with his eyes closed. After taking the drug, it is much easier for a girl to be considered a sexual giant, because she will begin to actively secrete lubricant, the genitals may increase slightly in size and swell. But all these processes also start naturally if a woman is excited and desires intimate contact with her partner. Therefore, for a healthy, sexually mature woman, the drug is simply useless. If desired, a woman can afford a course of taking Viagra. The asking price is about 500 rubles for a small package. As the dosage increases, financial costs increase, so you should not take this medicine for prophylaxis. In fact, if Viagra is purchased at a pharmacy, its price will be very high compared to a number of other drugs with similar indications. Do not buy this medicine at random; consult your doctor.