Vizarsin - instructions for use, analogs, reviews and release forms (tablets 25 mg, 50 mg and 100 mg, dispersed Ku-Tab) drug for the treatment of impotence and increased potency in men. Composition and interaction with alcohol

In this article, you can read the instructions for using the drug Wizarsin. Comments of visitors of the site - consumers of this medication, as well as opinions of doctors of specialists on the use of Visarsin in their practice are presented. A big request is to actively add their feedback on the drug: the medicine helped or did not help get rid of the disease, which were observed complications and side effects, possibly not declared by the manufacturer in the annotation. Analogues Vizarsina in the presence of existing structural analogues. Use to treat impotence and increase potency in men. Composition and interaction of the drug with alcohol.

Wizarsin - a drug for the treatment of erectile dysfunction and increased potency. Sildenafil (the active substance of the drug Vizarsin) is a potent selective inhibitor of cyclo-guanosine monophosphate (cGMP) -specific phosphodiesterase type 5 (PDE5). Restores impaired erectile function by increasing the flow of blood to the penis.

The physiological process underlying the erection of the penis includes the release of nitric oxide (NO) in the cavernous body under the influence of sexual stimulation. NO activates the enzyme guanylate cyclase and increases the cGMP content, which relaxes the smooth muscle cells of the cavernous body and promotes an increase in blood flow. Sildenafil has a peripheral effect on the erection. Does not have a direct relaxing effect on an isolated cavernous body in humans, but enhances the relaxing effect of NO. When NO / cGMP is activated, which occurs under the influence of sexual stimuli, suppression of PDE5 with sildenafil leads to an increase in cGMP in the cavernous body. Thus, sexual stimulation is necessary to develop the desired pharmacological action of sildenafil.

Studies have shown that sildenafil is selective for PDE5, which is involved in the process of developing an erection. Its activity against PDE5 is superior to that of other known phosphodiesterases. He is 10 times less effective in relation to PDE6, which takes part in the photoreference in the retina. At maximum recommended doses, it is 80 times less selective for PDE1, 700 times for PDE2, PDE3, PDE4, PDE7, PDE8, PDE9, PDE10 and PDE11.

The activity of sildenafil with respect to PDE5 is approximately 4000 times greater than its activity with respect to FDEZ, cAMP-specific phosphodiesterase, involved in cardiac contraction. Sildenafil causes a small transient decrease in blood pressure, which in most cases has no clinical manifestations. The average maximum decrease in systolic blood pressure in the supine position after taking sildenafil inside at a dose of 100 mg is 8.4 mm Hg. The corresponding change in diastolic blood pressure is 5.5 mm Hg. This decrease in blood pressure is due to the vasodilating properties of sildenafil, possibly associated with an increase in the level of cGMP in the smooth muscle cells of the vessels. A single application of sildenafil inside at a dose of up to 100 mg was not accompanied by clinically significant changes in the ECG in healthy volunteers.

Vizarsin does not affect cardiac output and does not change blood flow through stenosed arteries.

Composition

Sildenafil citrate + auxiliary substances (Vizarsin).

Sildenafil + auxiliary substances (Visarsin Ku-Tab).

Pharmacokinetics

After oral administration, Vizarsin is rapidly absorbed. Absolute bioavailability averages 40% (25-63%). After a single oral dose of 100 mg Cmax is 18 ng / ml and is achieved with fasting for 30-120 minutes. When taking sildenafil in combination with fatty food, the rate of absorption decreases; Tmax increases by 60 min, and Cmax decreases by an average of 29%. Sildenafil and its main circulating N-desmethyl metabolite are approximately 96% bound to plasma proteins. Binding to proteins does not depend on the total concentration of sildenafil. Less than 0.0002% of the dose (an average of 188 ng) was detected in the sperm 90 minutes after taking sildenafil. Sildenafil is metabolized, mainly by the action of microsomal isoenzymes of the liver CYP3A4 (main pathway) and CYP2C9.

The main circulating metabolite, which is formed as a result of N-desmethylation of sildenafil, undergoes further metabolism.By the selectivity of action on PDE, the metabolite is comparable to sildenafil, and its activity against PDE5 is approximately 50% of the activity of sildenafil itself. The concentration of the metabolite in the plasma is approximately 40% of that of sildenafil. N-desmethyl metabolite undergoes further metabolism; its terminal T1 / 2 is about 4 hours.

After ingestion, sildenafil is excreted as metabolites mainly with feces (approximately 80% of the dose) and, to a lesser extent, with urine (approximately 13% of the dose).

In elderly patients (65 years and older), the clearance of sildenafil is reduced, and the concentration of free active substance in the plasma is approximately 40% higher than its concentration in young (18-45 years) patients.

Indications

• treatment of erectile dysfunction characterized by inability to achieve or maintain an erection penis sufficient for a satisfactory sexual intercourse (impotence);
• pulmonary hypertension.

Forms of release

Tablets coated with 25 mg, 50 mg and 100 mg.

Tablets, dispersible in the oral cavity of 25 mg, 50 mg and 100 mg (Ku-Tab).

Instructions for use and dosing regimen

Vizarsin tablets

The drug is taken orally.When using the drug Vizarsin with food, the effect of the drug may develop later than when it is applied on an empty stomach.

The recommended dose is 50 mg per day, taken about 1 hour before the alleged sexual activity. Depending on the effectiveness and tolerability of the dose of the drug, Vizarsin can be increased to 100 mg per day or reduced to 25 mg per day.

The maximum recommended dose is 100 mg per day. The maximum recommended frequency of the drug is 1 time per day.

Correction of the dose of the drug Vizarsin in elderly patients is not required.

Tablets Vizarsin Ku-Tab

Treatment of erectile dysfunction: Dissolve the dispersible tablet about 1 hour before the planned sexual activity. A single dose is 50 mg. With regard to efficacy and tolerability, the dose can be increased to 100 mg or reduced to 25 mg. The maximum single dose is 100 mg. The maximum frequency of application is 1 time per day. For elderly patients over the age of 65 and with concomitant disorders of kidney or liver function, the dose is 25 mg.

Pulmonary hypertension: inside 20 mg 3 times a day with an interval of about 6-8 hours, regardless of food intake.The maximum daily dose is 60 mg. Patients with impaired renal function are not required to adjust the dose, but with poor tolerability, the dose is reduced to 20 mg twice a day.

Side effect

• reactions of hypersensitivity (including skin rash);
• headache;
• dizziness;
• drowsiness;
• cerebrovascular disorders;
• fainting;
• transient ischemic attacks;
• convulsions;
• visual impairment;
• transient disorders of color perception (chromatopsy);
• defeat of the conjunctiva;
• violation of tear formation;
• anterior ischemic neuropathy of non-arterial genesis (NAION);
• occlusion of the vessels of the retina;
• narrowing of the fields of vision;
• dizziness;
• noise in ears;
• deafness;
• flushes of blood to the skin of the face;
• a feeling of palpitations;
• tachycardia;
• arterial hypertension;
• arterial hypotension;
• myocardial infarction;
• atrial fibrillation;
• ventricular arrhythmia;
• unstable angina;
• sudden cardiac arrest;
• nasal congestion;
• nose bleed;
• dyspepsia;
• vomiting, nausea;
• dry mouth;
• myalgia;
• priapism;
• prolonged erection;
• chest pain;
• general weakness.

Contraindications

• simultaneous application with donators of nitric oxide (such as amyl nitrite) or nitrates in any dosage form, because Vizarsin can enhance the hypotensive effect of nitrates (given the known effect of sildenafil on NO / cGMP);
• use in men who are not recommended for sexual activity (eg, patients with severe cardiovascular diseases, such as unstable angina or severe heart failure);
• decreased vision due to anterior ischemic optic neuropathy of non-arterial genesis (NAION), regardless of whether it is bound or not with the use of PDE5 inhibitors;
• established congenital degeneration of the retina, incl. Retinitis pigmentosa (retinitis pigmentosa);
• severe liver dysfunction;
• arterial hypotension (blood pressure less than 90/50 mm Hg);
• recent stroke or myocardial infarction;
• children and adolescents under 18;
• hypersensitivity to sildenafil or to any other component of the drug.

Application in pregnancy and lactation

Vizarsin is not suitable for use in women.

Use in children

Contraindicated in children and adolescents under the age of 18 years.

Application in elderly patients

Correction of the dose of the drug Vizarsin in elderly patients is not required.

special instructions

Before prescribing drug therapy, you need to carefully evaluate the history and conduct a clinical examination to diagnose erectile dysfunction and to identify its possible causes.

Sexual activity represents a certain risk in the presence of diseases of the cardiovascular system, therefore, before starting any therapy for erectile dysfunction, one should evaluate the patient's condition. Sildenafil has a systemic vasodilator effect, leading to a small and transient decrease in blood pressure. Before using sildenafil, you should carefully evaluate the risk of possible undesirable vasodilating effects in patients with related diseases, especially against the background of sexual activity. Increased susceptibility to vasodilators is observed in patients with left ventricular outflow tract obstruction (eg, aortic stenosis, hypertrophic obstructive cardiomyopathy), as well as with a rare syndrome of multiple systemic atrophy manifested by severe disruption of autonomic BP regulation.

In post-marketing use of sildenafil, serious cardiovascular events were noted, including myocardial infarction, unstable angina, sudden coronary death, ventricular arrhythmias, hemorrhagic stroke, transient ischemic attacks, hypertension or hypotension. Most of these patients, but not all, had predisposing factors of cardiovascular risk. Many of these phenomena developed within a short time after taking sildenafil even in the absence of sexual activity. It is impossible to determine precisely whether these phenomena are directly related to the described or other factors.

Drugs for the treatment of sexual dysfunction, including Vizarsin, should be used with caution in patients with anatomical deformities of the penis (such as angulation, cavernous fibrosis or Peyronie's disease), as well as in patients with conditions predisposing to priapism (such as sickle cell anemia, multiple myeloma or leukemia).

The safety and effectiveness of sildenafil in combination with other drugs intended for the treatment of erectile dysfunction have not been studied, so the use of such combinations is not recommended.

Against the background of the use of sildenafil and other PDE5 inhibitors, cases of visual disturbance and development of anterior ischemic optic neuropathy of non-arterial genesis were noted. Patients should be informed that in case of loss of vision or sudden deterioration of the patient, stop using Vizarsin and immediately consult a doctor.

Sildenafil should be used with caution in patients taking alpha-blockers, since the simultaneous use of sildenafil and alpha-blockers can lead to symptomatic arterial hypotension in selected susceptible patients. Arterial hypotension most often develops 4 hours after the application of sildenafil. To minimize the risk of postural hypotension in such patients, sildenafil should be started only after stabilization of hemodynamics is achieved against the background of the use of alpha-adrenoblockers. The use of sildenafil should be started with a dose of 25 mg. In addition, it should be explained to the patient what can be done in case of development of arterial hypotension.

Studies with human platelets have shown that sildenafil potentiates the anti-coagulant effect of sodium nitroprusside. There is no information on the safety of sildenafil in patients with bleeding or active peptic ulcers. Therefore, sildenafil can be used in such patients only after a thorough assessment of the benefit / risk ratio.

The drug Vizarsin contains lactose, so you should be careful when using the drug with lactose intolerance, lactase deficiency, glucose-galactose malabsorption syndrome.

Vizarsin is not suitable for use in women.

Impact on the ability to drive vehicles and manage mechanisms

No studies have been conducted to study the effect on the ability to drive vehicles and work with mechanisms, but due to the possibility of visual impairment, dizziness, one should carefully consider the individual effect of the drug, especially at the beginning of treatment and when changing the dosage regimen.

Drug Interactions

The effect of other drugs on the pharmacokinetics of Vizarsin

The metabolism of sildenafil occurs mainly under the action of cytochrome P450 - CYP3A4 isoenzymes (the main pathway) and CYP2C9 (a secondary pathway), so inhibitors of these isoenzymes can reduce the clearance of sildenafil, and inductors, respectively, increase the clearance of sildenafil.

Simultaneous use of inhibitors of the isoenzyme CYP3A4 (such as ketoconazole, erythromycin, pimetidine) and sildenafil reduces its clearance.

Ritonavir increases AUC sildenafil 11 times; simultaneous use of these drugs is not recommended. If it is necessary to simultaneously apply with ritonavir, the maximum single dose of the drug Vizarsin should not exceed 25 mg, and the frequency of application - once every 48 hours.

With the simultaneous use of vizarsine (100 mg once a day) and the inhibitor of the HIV protease and inhibitor of the isoenzyme CYP3A4 saquinavir, while achieving a constant concentration of saquinavir in the blood (1200 mg 3 times daily), C max sildenafil increases by 140%, and AUC - by 210%. Sildenafil has no effect on the pharmacokinetics of saquinavir. More potent inhibitors of the CYP3A4 isoenzyme, such as Ketoconazole and itraconazole, are presumably likely to cause more pronounced changes in the pharmacokinetics of sildenafil.

The use of sildenafil in a dose of 100 mg once a day simultaneously with erythromycin, a specific inhibitor of CYP3A4, against the background of achieving a constant Erythromycin concentration in the blood (500 mg twice a day for 5 days) leads to an increase in the AUC of sildenafil by 182%. In healthy male volunteers, Azithromycin (500 mg / day for 3 days) did not affect AUC, Cmax, Tmax, rate of elimination rate and T1 / 2 sildenafil or its main circulating metabolite. Cimetidine (800 mg), a nonspecific inhibitor of CYP3A4, when taken together with sildenafil (50 mg) by healthy volunteers caused an increase in the concentration of sildenafil in plasma by 56%.

Grapefruit juice, a weak inhibitor of CYP3A4, may moderately increase the plasma concentration of sildenafil.

Single application of antacids (magnesium hydroxide / aluminum hydroxide) does not affect the bioavailability of sildenafil.

Although no special pharmacokinetic studies have been conducted with all the drugs, population pharmacokinetic analysis revealed no changes in the pharmacokinetics of sildenafil while simultaneous use with such inhibitors of the CYP2C9 isoenzyme as tolbutamide, warfarin, phenytoin,with inhibitors of the isoenzyme CYP2D6 (selective serotonin reuptake inhibitors and tricyclic antidepressants), thiazide and similar diuretics, loop and potassium-sparing diuretics, ACE inhibitors, calcium channel blockers, beta adrenoblockers or inducers of the CYP450 isoenzyme (such as rifampicin, barbiturates).

Nicorandil is a hybrid of nitrate and potassium channel activator. Due to the presence of a nitrate component, it can enter into an undesirable interaction with sildenafil.

The effect of Vizarsin on other drugs

Sildenafil is a weak inhibitor of cytochrome P450 - 1A2, 2C9, 2C19, 2D6, 2E1 and 3A4 isoenzymes (IC50 more than 150 μmol). When sildenafil is used in recommended doses, its Cmax in blood plasma is about 1 μmol, so it is unlikely that Vizarsin can affect the clearance of the substrates of these isoenzymes.

There are no data on the interaction of sildenafil with nonspecific inhibitors of phosphodiesterases, such as theophylline or dipyridamole.

Given the known effect of Vizarsin on NO / cGMP, it can enhance the hypotensive effect of nitrates, so its simultaneous use with nitrate donators or nitrates in any dosage form is contraindicated.

Simultaneous use of sildenafil and alpha-adrenoblockers can lead to symptomatic arterial hypotension in selected susceptible patients. Arterial hypotension most often develops 4 hours after taking sildenafil. In three special studies on drug interactions in patients with benign prostatic hyperplasia (BPH) with stable hemodynamics, doses of 4 mg and 8 mg of Doxazosin were simultaneously administered with sildenafil (in doses of 25 mg, 50 mg, or 100 mg). In all three studies, there was an average additional BP reduction in the prone position of 7/7 mm Hg, 9/5 mm Hg, and 8/4 mm Hg. and an additional decrease in blood pressure in a standing position at 6/6 mm Hg, 11/4 mm Hg, and 4/5 mm Hg, respectively. With simultaneous use of sildenafil and doxazosin in patients with stable hemodynamics against the background of doxazosin, rare cases of symptomatic postural hypotension have been noted. In these described cases, dizziness or lightness developed, but without the development of syncope. To reduce the likelihood of orthostatic hypotension, it is necessary to achieve a stable state with alpha-adrenoblockers before initiating the use of sildenafil.

There was no significant interaction with the simultaneous use of sildenafil (at a dose of 50 mg) and tolbutamide (250 mg) or Warfarin (40 mg), which are metabolized with CYP2C9.

Sildenafil (at a dose of 50 mg) does not potentiate the increase in bleeding time caused by Acetylsalicylic acid (at a dose of 150 mg).

Vizarsin (in a dose of 50 mg) does not potentiate the hypotensive effect of ethanol (alcohol) in healthy volunteers with a maximum ethanol content of 80 mg / dL.

Synthesis of available data on the following drugs: diuretics, beta-blockers, ACE inhibitors, angiotensin receptor blockers 2, central-acting antagonists, adrenergic blockers, calcium channel blockers and alpha-adrenoreceptor blockers did not reveal differences in the profile of adverse reactions in patients who simultaneously took sildenafil or placebo. In a special study, sildenafil (100 mg) was used concomitantly with Amlodipine in patients with hypertension, and further reduced systolic blood pressure in the prone position, on average, by 8 mm Hg, and diastolic blood pressure by 7 mm Hg. Art.This additional reduction in blood pressure was the same as with the use of only sildenafil in healthy volunteers.

Analogues of the drug Vizarsin

Structural analogs for the active substance:

• Viagra;
• Viassan LF;
• Vigrande;
• Visarsin Ku-tab;
• Dynamics;
• Maxigra;
• Olmax Strong;
• Revacio;
• Silafil;
• Sildenafil;
• Sildenafil citrate;
• Taxiere;
• Tornethis;
• Erexel.

Analogues on the curative effect (potency regulators):

• Afrodor 2000;
• Veromax;
• Verona;
• Viagra;
• Zidena;
• The Impaza;
• Yohimbine hydrochloride;
• Levitra;
• Muse;
• Priligi;
• Reilis;
• Cialis;
• Spem;
• Spemann forte;
• Tentex forte;
• Testalamine powder;
• Testalamine;
• Himkoline;
• Edex.

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