Viagra

• Structure
• Release form
• Pharmacological action
• Pharmacodynamics and pharmacokinetics
• Indications to use: for what the tablet Viagra?
• Contraindications
• Side effects
• Viagra, application instruction
• Overdose
• Interaction
• Terms of sale
• Storage conditions
• Period of validity
• Special instructions
• Analogs
• With alcohol
• Responses

Structure

A part of Viagra sildenafit (Sildenafil) can be concentration of 25, 50 or 100 mg.

In addition to a sildenafil as a part of drug are present: microcrystallic cellulose (Microcrystalline cellulose), calcium hydrophosphate (Calcium hydrophosphate), sodium of a krosskarmeloz (Croscarmellose sodium), magnesium stearate (Magnesium stearate).

For production of the covering tablet of a film cover Opadry blue and transparent are used.

The composition of Viagra does not differ depending on concentration of active agent.

Release form

Dosage form of Viagra — film coated tablets.

Tablets are slightly biconvex, have the rhomboid form, edges their cut off and rounded, color — blue. On one party of a tablet there is a text of "Pfizer", with another — "VGR 25/50/100" (depending on concentration of a sildenafil).

In one packaging there can be 1, 2, 4 or 12 tablets.

Pharmacological action

Effect of drug is directed to recovery of physiologic reaction to sexual excitement.

Pharmacodynamics and pharmacokinetics

The drug Viagra is intended for treatment of frustration of an erection.

At emergence of sexual excitement means updates reduced erectile function due to strengthening of inflow of blood to a penis.

The natural mechanism of an erection is connected with release at sexual stimulation in a cavernous (cavernous) body of a penis of NO (a nitrogen oxide) which promotes guanylate cyclase enzyme activation.

The last, in turn, stimulates increase of concentration of tsGMF (a cycling guanozinmonofosfat). As a result of it the smooth muscles of a cavernous body relax and blood inflow amplifies.

Sildenafil represents powerful and selection inhibitor of tsGMF-specific FDE-5 (phosphodiesterase-5) in a cavernous body where FDE-5 plays an important role in the course of disintegration of tsGMF.

Effect of substance on erectile function has peripheral character: drug does not render the direct running-down effect on the isolated cavernous body of the person, at the same time powerfully strengthening the weakening action of a nitrogen oxide on it.

That under the influence of a sildenafil the necessary therapeutic effect developed, sexual excitement is required.

TCmax (time of achievement of the maximum plasma concentration) at oral administration of a sildenafil on an empty stomach makes from 0,5 to 2 hours, the indicator of bioavailability is ranging from 25 to 60%.

At administration of drug with greasy food the pharmacokinetic indicator of Cmax decreases at least by 20% (sometimes to 40%), on its achievement leaves from 1,5 to 3 hours.

Metabolization of a sildenafil occurs in a liver under the influence of microsomal isoenzymes of system of cytochrome.

Sildenafit an elimination half-life in pure form and N-dezmetilmetabolita which is its main metabolite — from 3 to 5 hours. Drug is removed in the form of inactive products of a metabolism. About 80% eliminirutsya with contents of intestines, about 15% eliminirutsya by kidneys.

Indications to use: for what the tablet Viagra?

In the description of medicine it is specified that Viagra is intended for treatment of frustration of an erection which are a consequence of vascular disorders or nervous breakdowns and are defined as inability to reach an erection of a penis and to support her during the time necessary for successful sexual contact.

Sexual stimulation is necessary for ensuring efficiency of drug.

Contraindications

Viagra has a number of contraindications. So, means is forbidden to be used at:

• hypersensitivity to the components which are its part;
• simultaneous use with nitrites and nitrates in any form, and also with donators of an oxide of nitrogen (for example, with amyle nitrite);
• existence of contraindications to maintaining sex life (for example if serious heart troubles and frustration of vascular system — a severe form of heart failure or unstable stenocardia are diagnosed for the patient);
• to loss of sight on one eye which was provoked by front ischemic optical neuropathy (neuropathy of an optic nerve) of not arterial genesis irrespective of whether this pathology has communication with the previous use of FDE inhibitors of the fifth type;
• dysfunctions of a liver of heavy degree.

Also women should not accept Viagra, to children and teenagers 18 years are younger. With care drug is appointed:

• at anatomic deformations of a penis (including, at a fibroplastic induration of a penis, fibrosis of cavernous bodies, an angulation, etc.);
• at diseases which can become the contributing factor to development of a priapism (a leukosis, a sickemia, thrombocytopenia, a multiple myeloma, etc.);
• at diseases which are followed by bleedings;
• to stomach ulcer or ulcer of 12 perstny guts in an aggravation stage;
• if the patient in last half a year had a myocardial infarction or a stroke;
• if the hereditary degenerative disease of a mesh cover of an eye is diagnosed for the patient (for example, a pigmental retinitis);
• at unstable stenocardia or heart failure;
• at arrhythmia which can pose threat of life of the patient;
• arterial hypotension (in cases when indicators of arterial pressure do not exceed 90/50 mm of mercury.) or hypertensia (in cases when indicators of arterial pressure do not exceed 170/100 mm of mercury.)

Side effects

As a rule, side effects which develop against Viagra use are characterized as easy or moderately expressed and have passing character. Frequency of development of undesirable symptoms increases in process of increase in a dosage.

The use of Viagra can become the reason:

• abdominal pains, back, muscles or joints;
• adynamy;
• grippopodobny syndrome;
• infections (including respiratory tracts and urinary system);
• diarrheas;
• nausea;
• increases of a tone of muscles;
• sleeplessnesses;
• nose congestions;
• inflammations of an adenoid tissue and mucous throat (pharyngitis);
• inflammations of adnexal bosoms of a nose (sinusitis);
• breath dysfunctions;
• enanthesis;
• disturbances of color perception of objects (usually similar change of sight is expressed benign and has passing character);
• conjunctivitis;
• dysfunctions of a prostate;

During clinical trials also such by-effects as sight misting, strengthening of perception of light, rhinitis, dizzinesses, a vazodilatation were registered.

At the use of drug in the raised doses at the patient the same side effects are noted, however there are they much more often than at observance of the dosing mode specified in the instruction.

In the course of post-marketing use of Viagra for certain patients in connection with the use of drug were fixed:

• to syncope, arterial hypotension, heartbeat, tachycardia;
• vomiting;
• long erection and/or priapism;
• reddening of eyes and pain in them;
• allergic reactions.

Viagra, application instruction

In the application instruction of Viagra it is specified that drug should be accepted orally. Tablets are recommended to be drunk to food as in that case their action develops more quickly.

Viagra — how to accept for men?

Medicine is issued in three dosages — 25, 50 and 100 mg. As a rule, for most of patients the starting dose makes 50 mg. A pill is taken on one approximately for an hour to sexual activity.

Their action begins 30-60 minutes later and remains for the next 4 hours. That drug worked quicker, it is recommended to be accepted to food.

Depending on expressiveness of effect and considering portability of drug the patient the dose can be corrected both in big, and in the smaller party.

In some cases adhere to other scheme — begin to take a pill with the minimum dosage, gradually raising it before the expressed therapeutic effect.

As it is correct to accept Viagra, the scheme of use and a dose of medicine the doctor defines individually, taking into account features of an organism of the patient.

The highest recommended dose — 100 mg. The maximum recommended frequency rate of receptions — once a day.

Patients of advanced age do not need to adjust the dosing mode.

Overdose

During researches which were conducted on healthy volunteers it was established that the single dose of a dose to 0,8 grams provokes the same side effects which were noted also at administration of drug in much smaller doses, however at the same time the frequency of their emergence and degree of manifestation increased.

The use of a sildenafil in a dose, equal 0,2 grams, does not lead to increase of efficiency of means, however provokes increase in frequency of cases of development of side effects. The most frequent are rushes of blood, dizzinesses, headaches, disturbances from organs of sight, dispepsichesky symptoms, a nose congestion.

In case of overdose of Viagra appoint the supporting treatment, usual for such situations. As sildenafit it is characterized by high extent of linkng with proteins of a blood plasma (the indicator of binding makes 96%) and it does not eliminirutsya with urine, acceleration of clearance of substance at a hemodialysis is considered improbable.

Interaction

Sildenafil is exposed to a metabolism in a liver, mainly under the influence of isoenzymes of CYP3A4 and partly under the influence of CYP2C9 therefore inhibitors of the specified isoenzymes reduce, and their inductors, respectively, increase clearance of a sildenafil.

So, 0,8 grams of Cimetidinum which is nonspecific CYP3A4 inhibitor in combination with 0,05 grams of a sildenafil provoke increase of plasma concentration of the last to 56%.

At reception 0,1 grams of a sildenafil in combination with erythromycin which is specific CYP3A4 inhibitor (in a case when erythromycin is accepted twice a day on 0,5 grams within 5 days) after constant concentration of erythromycin in blood is reached, AUC of a sildenafil increases by 182%.

Concomitant single dose 0,1 grams of a sildenafil with 1,2 grams of a sankvinavir which is CYP3A4 inhibitor and HIV proteases, at frequency rate of uses of the last three times a day: against achievement of constant plasma concentration of a sankvinavir the indicator of AUC of a sildenafil increases by 210%, and Cmax — for 140%. At the same time sildenafit does not change pharmacokinetics of a sankvinavir.

Ketokonazol and itrakonazol which are more powerful inhibitors of an isoenzyme CYP3A4 can exert stronger impact on pharmacokinetic parameters of a sildenafil.

At the simultaneous use sildenafit 0,1 grams (once) and a ritonavir (on 0,5 grams twice a day) which is powerful inhibitor of isoenzymes of system of P450 cytochrome and inhibitor of HIV protease, after achievement of constant plasma concentration of a ritonavir of AUC of a sildenafil increases by 11 times (by 1000%), and Cmax — by 4 times (for 300%).

After 24 hours plasma concentration of a sildenafil makes 200 ng/ml while after single use of one sildenafil this indicator makes 5 ng/ml.

Patients who accept sildenafit in the dosages recommended by the instruction and in addition receive powerful CYP3A4 inhibitors, well transfer Viagra.

Sildenafil influences ways of a metabolism of NO/tsGMF and exponentiates hypotensive effect of nitrates (both at use according to acute indications, and at prolonged treatment by these means). In this regard reception of a sildenafil with donators of an oxide of nitrogen or nitrates is contraindicated.

The single dose of antiacid drugs (aluminum hydroxide or magnesium hydroxide) does not exert impact on bioavailability of drug.

At some sensitive patients against simultaneous use of a sildenafil and α-adrenoblockers symptomatic hypotension can develop.

A little significant interaction of drug with warfarin (0,04 grams) and Tolbutamidum (0,25 grams) it is not established. Also interaction of a sildenafil in a dose of 0,1 grams with amlodipiny is not established at use of these drugs for patients with arterial hypertension.

Besides, sildenafil:

• in a dose of 0,1 grams does not change pharmacokinetics of inhibitors of HIV protease at their constant concentration in blood;
• in a dose of 0,05 grams at a concomitant use with 0,15 grams of acetylsalicylic acid does not provoke additional increase in duration of bleeding;
• in a dose of 0,05 grams does not cause strengthening of hypotensive effect of ethanol at a maximum level of the last in blood in healthy volunteers about 80 mg/dl;
• does not provoke emergence additional by-effects at simultaneous use with anti-hypertensive means.

Terms of sale

Drug is not released without recipe.

Storage conditions

Viagra is included in the list B. It is recommended to store drug in the place, dry, unavailable to children. Optimum temperature — is not above 30 degrees Celsius.

Period of validity

5 years.

Special instructions

What is Viagra?

Viagra — what is it that does and for what it is necessary? Viagra is the first pharmaceutical drug which shows the reliable and expressed efficiency at most of the patients suffering from frustration of an erection. Means promotes an organism response at impact on it of sexual incentives.

To Wikipedias about medicine it is written that it is initial it was created for improvement of a blood-groove in a cardiac muscle, treatment of an ischemic disease and stenocardia.

However in the early nineties of the XX century as a result of clinical trials it was established that medicine makes the minimum impact on a cordial blood stream, but at the same time stimulates a blood stream in bodies of a small pelvis and, in particular, in a penis.

How drug works?

The mechanism of action of tablets consists in increase in volume of blood which arrives to a penis. Drug exerts impact only on natural origins of an erection and provokes a natural erection.

When sexual intercourse is complete, there is a natural relaxation of a penis.

Means does not provoke strengthening of a sexual inclination, and does not belong to the category of the raising libidos and "exciting" drugs, its active agent works only when the man experiences natural sexual excitement.

Sexual norm — that it and how to define it?

The man at whom the erection arises and remains is considered healthy, allowing it to have sex and to successfully complete each sexual intercourse.

If the person considers himself healthy, but at the same time at him against use of Viagra improvement of an erection is noted, it is possible to assume that he to some extent suffers from erectile dysfunction.

The principle of effect of Viagra on the healthy man

Quite often there are questions whether healthy men can accept drug and that will be if to take the Viagra medicine and whether Viagra is harmful to the healthy man.

Healthy men are not forbidden to accept drugs of a sildenafil as they promote stabilization of work of generative organs, emergence of a repeated erection and extension of sexual intercourse.

Besides, Viagra possesses ability to reduce influence of the factors preventing emergence of an erection or reducing its stability (including at healthy men). Tablets improve operation of the sexual device at an indisposition, nervousness and fatigue.

Means does not provoke an uncontrolled erection and raises it when the man is excited. If excitement is absent, then drug does not render any effect.

As for safety of use of means, clinical trials allowed to establish that the patients accepting Viagra and placebo stopped use of drug in connection with the arising by-effects approximately with an identical frequency: termination frequency among the patients accepting Viagra — 2,5%, placebo — 2,3%.

Taking the pill Viagra, it is necessary to consider possible medicinal interactions of this means. In particular, interaction with nitrates which are used for treatment of heart diseases.

Whether there is a dependence on Viagra?

Cases of emergence of physical dependence on drug are not established. However, if to take a pill every day and for a long time, the probability of emergence of dependence psychological is not excluded.

That is at the continuous use of medicine the patient so gets used to effect of stabilization of an erection that after its cancellation there can be an illusion of deterioration in a potentiality.

As a rule, it is expressed in feeling that the erection became less stable and is more subject to influence of external factors. But in general it not so, the person just returns to a usual rhythm of sex life in which dependence on fatigue, a psychoemotional state, and also the general state of health is traced.

How to accept drug and through how many it works on time?

Viagra is accepted on one tablet approximately for an hour before sexual contact. The effect of use of a sildenafil develops in 30-60 minutes after reception.

On time action continues within 4 hours.

How Viagra affects women and girls?

According to the statistics about 40% of women suffer from different disturbances of sexual function which are both a consequence of somatopathies, and the reasons of psychological character.

In this regard, and also considering popularity and efficiency of men's Viagra, the questions "Whether Viagra Affects Women?" began to appear.

Specialists answer that action of a sildenafil for women is similar to how Viagra for men works. For girls it is shown in strengthening of blood supply of generative organs and their somatic stimulation. Besides, at women the amount of the emitted natural greasing increases, sensitivity and excitability and, as a result, chances to reach an orgasm increase.

Nevertheless, precisely it is much more difficult to define degree of efficiency of means for women, than for men.

Besides, doctors consider that it is not enough data on safety of Viagra for women therefore they did not recommend to accept it to healthy women. However for the women who early entered the menopause period (till 50 flyings) with all that it implies unpleasant symptoms, and also for the women who underwent a serious gynecologic operation (for example, a hysterectomy), reception of such tablets can become almost only chance to have normal sex.

It is necessary to remember what affects the person Viagr properly only in the presence of sexual stimulation.

Viagra which is let out by the American company Pfizer is still intended only for men, and the pharmaceutical companies develop other drugs for women.

The tablets Viagra for women in drugstores are on sale under the name "Women's Viagra" (Female Viagra). The dosage sildenafit in one tablet — 100 mg (100 mg).

As alternative to Viagra such means as the Female activator of a drop Gold Fly, Silver Fox, Span.Fliege Minitablet, Lokmanzade syrup (the Turkish drug in jars which can be used as aphrodisiac both by men, and women), etc. can be recommended.

How to make Viagra in house conditions?

National recipes of Viagra enjoy wide popularity. First, the majority of them underwent testing time. Secondly, to make with own hands Viagra, use exclusively natural ingredients. Therefore, the probability of side effects from such means will be almost equal to zero.

Garlic tincture, mix of the crushed nuts (walnut or any other) reckon with natural honey and ginseng tincture (the finished pharmaceutical product which is on sale in a drugstore) as the simplest and efficient means.

For preparation of tincture of garlic of kilograms of the peeled and crushed garlic fill in with three liters of boiled water and leave to be drawn within 30 days. Accept means daily on a teaspoon, all can will not be spent yet.

Tincture of a ginseng is taken twice or three times a day approximately for half an hour to food till 25-30 of drops (not later than 4 hours to a dream).

Analogs of Viagra

The drugs close to Viagra on the action mechanism

Analogs of the tablets Viagra are AFALAZA, Sialis, Verona, Zidena, Raylis, Impaza, Yohimbine Spiegel, Kaverdzhekt, Yohimbine a hydrochloride, Levitra, Sirbida.

Viagra generics

Viasan of LF, Viagra gel, Women's Viagra, Capsules for men "Favourite" (The Chinese natural Viagra), Vizarxing, Dinamiko, Maksigra, Vigrande, Silafil, Sildenafil (Vertexum, Sandoz), Tornetis, Ereksezil, Vizarxing Ku-tab, Olmaks Strong.

As Viagra substitute for men drugs which make from plants and various parts of animals can be used (for example, a tortoise armor, a show off of a deer, testicles of the Tibetan yak, etc.): Boss Royal Viagra, Vuka-Vuka, Impaz, Sealeks, Yokhimbe forte, Biagra, Yarsagumba and other drugs.

As the market is provided by rather large amount of drugs for improvement of an erection at men, quite naturally there are questions "What It Is Better — Sialis Or Viagra?", "What to Replace Drug with?", "What to Choose — Viagra or Dinamiko?".

Definite answer that it is better — Viagra or Levitra, Viagra or Sialis, Viagra or Dinamiko, no.

Dynamics is a synonym of drug, that is its basis is made by the same active ingredient, as at Viagra. The only differences of both means are the producer and the price (Dinamiko is slightly cheaper than the structural analog).

Comparison of Viagra with Levitra or Sialis is not absolutely correct as drugs have different active ingredients and, therefore, the action mechanism. Sialis take approximately in 10 minutes prior to sexual activity, to Levitr — in 20 minutes, Viagra — for half an hour-hour.

At the same time duration of effect of drugs is also various: for Viagra it makes 4 hours, for Levitra — from 4 to 10 hours, for Sialis — till 36 o'clock (Sialis of 40 mg acts till 72 o'clock).

The effect of Levitra and Sialis's use does not depend on meal (and from the quantity eaten), besides, Levitra is compatible to alcohol, and the alcohol has no significant effect on Sialis's efficiency. As for Viagra, it is optimum to accept this drug on a hungry stomach.

Quite often the price of analogs is cheaper than the price of original drug. So, as more available Russian analog in a drugstore it is possible to get tablets Sildenafil.