sildenafil | Vizarsin tablets 50 mg, 4 pcs.
Special Price
$23.00
Regular Price
$34.00
In stock
SKU
BID471044
Release form
tablets
tablets
Release form
tablets
Packing
4 pcs.
Pharmacological action
Pharmacological action - restoring erectile function, vasodilating.
Sildenafil is a potent selective inhibitor of cGMP-specific PDE-5. Restores impaired erectile function by increasing blood flow to the penis.
The physiological process that underlies penile erection involves the release of nitric oxide (NO) in the cavernous body through sexual stimulation. NO activates the guanylate cyclase enzyme and increases the content of cGMP, which relaxes the smooth muscle cells of the cavernous body and helps to fill it with blood.
Sildenafil has a peripheral effect on erection. It does not have a direct relaxing effect on an isolated human cavernous body, but enhances the relaxing effect of NO. When the NO / cGMP connection is activated, which occurs under the influence of sexual stimuli, the inhibition of PDE-5 by sildenafil leads to an increase in cGMP in the cavernous body. Thus, for the development of the desired pharmacological action of sildenafil, sexual stimulation is necessary. In vitro studies have shown that sildenafil is selective for PDE-5, which is involved in the development of an erection. Its activity against PDE-5 is superior to activity against other known PDE. It is 10 times less effective with respect to PDE-6, which takes part in retinal photo transmission. At the maximum recommended doses, it is 80 times less selective for PDE-1, 700 times for PDE-2, 3, 4, 7, 8, 9, 10 and 11.
Sildenafil activity in relation to PDE-5 is about 4000 times superior to its activity against PDE-3, a cAMP-specific PDE involved in heart contraction.
Sildenafil causes a small and transient decrease in blood pressure, which in most cases has no clinical manifestations. The average maximum decrease in SBP in the supine position, after taking sildenafil inside at a dose of 100 mg, is 8.4 mm RT. Art. The corresponding change in blood pressure is 5.5 mm RT. Art. This decrease in blood pressure is due to the vasodilating properties of sildenafil, possibly associated with an increase in the level of cGMP in vascular smooth muscle cells. A single oral intake of sildenafil in a dose of up to 100 mg was not accompanied by clinically significant changes in the ECG in healthy volunteers.
Sildenafil does not affect cardiac output and does not alter blood flow through stenosed arteries.
Contraindications
Hypersensitivity to sildenafil or any other component of the
preparation Simultaneous administration with NO donors (such as amyl nitrite) or nitrates in any form (given the known effect of sildenafil on NO / cGMP, sildenafil may enhance the hypotensive effect) who are not recommended for sexual activity (for example, patients with severe cardiovascular diseases such as unstable angina or severe heart failure)
Patients with low vision due to anterior ischemic optic neuropathy of non-arterial origin (NAION), whether or not it is associated with the use of PDE-5 inhibitors
Severe hepatic dysfunction
Arterial hypotension (blood pressure less than 90/50 mm Hg)
Recent stroke or myocardial infarction
naya congenital retinal dystrophy (including retinitis pigmentosa (retinitis pigmentosa)
age of 18
As registered indications VizarsinВ® drug is not intended for use in women
Precautions:.. lactose intolerance, lactase deficiency, glucose-galactose malabsorption syndrome CCC syndrome multiple systemic atrophy anatomical deformation of the penis priapism sickle cell anemia multiple myeloma leukemia simultaneous administration of alpha-blockers.
Use during pregnancy and lactation
According to the registered indication, the drug Vizarsin® is not intended for use in women.
Special instructions
Before prescribing drug therapy, you need to carefully evaluate the history and conduct a clinical examination to diagnose erectile dysfunction and identify its possible causes.
Sexual activity poses a certain risk in the presence of CVD diseases, therefore, before starting any therapy for erectile dysfunction, the doctor must evaluate the patient's condition. Sildenafil has a systemic vasodilator effect, leading to a small and transient decrease in blood pressure. Before using sildenafil, the doctor should carefully assess the risk of possible unwanted vasodilating effects in patients with relevant diseases, especially against the background of sexual activity. Increased susceptibility to vasodilators is observed in patients with left ventricular outflow tract obstruction (e.g. aortic stenosis, hypertrophic obstructive cardiomyopathy), as well as a rare syndrome of multiple systemic atrophy, which manifests itself as a severe violation of the autonomous regulation of blood pressure.
VizarsinВ® enhances the hypotensive effect of nitrates.
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 cardiovascular risk factors. Many of the noted phenomena developed within a short period of time after taking sildenafil, even in the absence of sexual activity. It is impossible to determine exactly whether these phenomena are directly related to the described or other factors.
Preparations for treating sexual dysfunction, including sildenafil, 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).
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.
With the use of sildenafil and other PDE-5 inhibitors, cases of visual impairment and the development of anterior ischemic optic neuropathy of non-arterial origin were noted. Patients should be informed that in case of loss of vision or its sudden deterioration, it is necessary to stop using VisarsinВ® and consult a doctor immediately.
Sildenafil should be used with caution in patients taking alpha-blockers, since the combined use of sildenafil and alpha-blockers can lead to symptomatic hypotension in some susceptible patients. Arterial hypotension most often develops 4 hours after the use of sildenafil. To minimize the risk of developing postural hypotension in these patients, sildenafil should only be taken after hemodynamic stabilization is achieved while taking alpha-blockers. Reception of sildenafil should be begun with a dose of 25 mg (see. "Indications"). In addition, the doctor should explain to the patient what can be done if hypotension develops.
Studies with human platelets have shown that sildenafil potentiates the anticoagulant effect of sodium nitroprusside in vitro. 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 careful assessment of the benefit / risk ratio.
VisarsinВ® contains lactose, in this connection, when using the drug, caution should be exercised in patients with lactose intolerance, lactase deficiency, glucose-galactose malabsorption syndrome.
VizarsinВ® is not intended for use in women.
Influence on the ability to drive vehicles and work with mechanisms. No studies have been conducted to study the effect on the ability to drive vehicles and work with mechanisms, but because of the possibility of visual impairment, dizziness, patients should evaluate the individual reaction to taking VisarsinВ®, especially at the beginning of treatment and when changing the dosage regimen.
Composition
1 tablet contains: active substance: sildenafil 50 mg
excipients: microcrystalline cellulose (Avicel PH101), calcium dihydrogen phosphate, croscarmellose sodium, hypromellose, microcrystalline cellulose (Avicel PH102 magnesium).
Dosage and Administration
Inside.
The recommended dose is 50 mg / day, which is taken if necessary, approximately 1 hour before the alleged sexual activity. Depending on the effectiveness and tolerability, the dose of the drug Visarsin® can be increased to 100 mg / day or reduced to 25 mg / day. The maximum recommended dose is 100 mg / day. The maximum recommended frequency of use of the drug is 1 time per day. When using the drug Vizarsin® with food, the effect of the drug may develop later than when using it on an empty stomach.
Special patient groups
Elderly patients. Vizarsin® dose adjustment is not required.
Impaired renal function. With mild and moderate severity of renal failure (Clcreatinin 30–80 ml / min) dose adjustment is not required, in severe renal failure (Cl creatinine less than 30 ml / min), the dose of the drug Vizarsin® should be reduced to 25 mg / day.
Impaired liver function. For patients with impaired liver function (e.g. cirrhosis), the dose is 25 mg / day.
Simultaneous use with other drugs
When used simultaneously with ritonavir, the maximum single dose of the drug Vizarsin® should not exceed 25 mg, and the frequency of use should be 1 time in 48 hours.
To reduce the likelihood of developing orthostatic hypotension, it is necessary to achieve a stable state during alpha therapy adrenoblockers before starting the use of sildenafil.
Side effects of
On the part of the immune system: rarely, hypersensitivity reactions.
From the nervous system: very often - headache often - dizziness infrequently - drowsiness, hypesthesia rarely - cerebrovascular events, fainting frequency unknown - transient ischemic attacks, convulsions.
On the part of the organs of vision: often - visual impairment, transient color perception disorders (chromatopsy) infrequently - conjunctival damage, impaired lacrimal formation frequency unknown - NAION, occlusion of the blood vessels of the fibers, narrowing of the visual fields.
On the part of the organ of hearing and the labyrinth: infrequently - dizziness, tinnitus rarely - deafness *.
From the CCC: often - flushing of the skin of the face infrequently - palpitations, tachycardia rarely - arterial hypertension, arterial hypotension, myocardial infarction, atrial fibrillation, frequency unknown - ventricular arrhythmia, unstable angina, sudden cardiac arrest.
From the respiratory system: often - nasal congestion rarely - nosebleeds.
From the digestive system: often - dyspepsia infrequently - vomiting, nausea, dry mouth.
From the skin: infrequently - a skin rash.
From the side of the musculoskeletal system: infrequently - myalgia.
From the reproductive system: frequency is unknown - priapism, prolonged erection.
General disorders and changes at the injection site: infrequently - chest pain, general weakness.
* Sudden hearing loss or loss was noted in a small number of cases during post-marketing use or during clinical trials of all PDE-5 inhibitors, including sildenafil.
Drug interaction
Effect of other drugs on the pharmacokinetics of sildenafil
In vitro studies. Sildenafil metabolism occurs mainly under the influence of cytochrome P450 (CYP) 3A4 isoenzymes (main pathway) and 2C9 (additional pathway), therefore, inhibitors of these isoenzymes can reduce sildenafil clearance, and inductors, respectively, increase sildenafil clearance.
In vivo studies. The simultaneous use of inhibitors of the CYP3A4 isoenzyme (such as ketoconazole, erythromycin, cimetidine) and sildenafil reduces its clearance.
Ritonavir increases the AUC of sildenafil by 11 times, the combined use of these drugs is not recommended.
With the simultaneous use of sildenafil (100 mg 1 time / day) and an HIV protease inhibitor and a CYP3A4 isoenzyme inhibitor saquinavir, while achieving a constant concentration of saquinavir in the blood (1200 mg 3 times a day), Cmax of sildenafil increases by 140%, and AUC - 210%. Sildenafil does not affect the pharmacokinetics of saquinavir. Stronger inhibitors of the CYP3A4 isoenzyme, such as ketoconazole and itraconazole, are thought to cause more pronounced changes in the pharmacokinetics of sildenafil.
The use of 100 mg of sildenafil 1 time / day together with erythromycin, a specific inhibitor of СУР3А4, against the background of achieving a constant concentration of erythromycin in the blood (500 mg 2 times / day for 5 days) leads to an increase in AUC of sildenafil by 182%. In healthy male volunteers, azithromycin (500 mg / day for 3 days) did not affect AUC, Cmax, Tmax, excretion rate constant, and T1 / 2 of sildenafil or its main circulating metabolite. Cimetidine (800 mg), a non-specific inhibitor of CYP3A4, when taken together with sildenafil (50 mg) by healthy volunteers caused an increase in plasma sildenafil concentration by 56%.
Grapefruit juice, a weak inhibitor of CYP3A4, can moderately increase plasma concentrations of sildenafil.
Single use of antacids (magnesium hydroxide / aluminum hydroxide) does not affect the bioavailability of sildenafil.
Although special pharmacokinetic studies with all drugs have not been conducted, Population pharmacokinetic analysis did not reveal a change in the pharmacokinetics of sildenafil when used simultaneously with inhibitors of the CYP2C9 isoenzyme such as tolbutamide, warfarin, phenytoin, with inhibitors of the CYP2D6 isoenzyme (SSRIs and tricyclic antidepressants, tyazide and similar diuretics, diuretic and diuretic diuretics, diuretics, and diuretic diuretics beta-blockers or inducers of CYP450 isoenzymes (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 serious interactions with sildenafil.
Effect of sildenafil on other drugs
In vitro studies. Sildenafil is a weak inhibitor of cytochrome P450 isoenzymes 1A2, 2C9, 2C19, 2D6, 2E1 and 3A4 (IC50 - 150 μmol). When using sildenafil at recommended doses, its Cmax in blood plasma is about 1 μmol, therefore, it is unlikely that Vizarsin® can affect the clearance of substrates of these isoenzymes.
No data are available on the interaction of sildenafil with non-specific PDE inhibitors such as theophylline or dipyridamole.
In vivo studies. Given the known effect of sildenafil on NO / cGMP, it can enhance the hypotensive effect of nitrates, so its simultaneous use with NO donors or nitrates in any form is contraindicated.
The simultaneous use of sildenafil and alpha-blockers can lead to symptomatic arterial hypotension in some 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 with stable hemodynamics while taking doxazosin (4 and 8 mg), sildenafil (25, 50 or 100 mg) was used simultaneously. In all three studies, an average additional decrease in blood pressure was observed in the supine position at 7/7 mm Hg. Art., 9/5 mm RT. Art. and 8/4 mm RT. Art., and an additional decrease in blood pressure in a standing position at 6/6 mm RT. Art., 11/4 mm RT. Art. and 4/5 mm RT. Art. respectively. With the simultaneous use of sildenafil and doxazosin in patients with stable hemodynamics while taking doxazosin, rare cases of the development of symptomatic postural hypotension have been noted. In these described cases, dizziness or a feeling of lightness developed, but without the development of fainting conditions.
No significant interactions were observed with the simultaneous use of sildenafil (50 mg) and tolbutamide (250 mg) or warfarin (40 mg), which are metabolized with CYP2C9.
Sildenafil (50 mg) does not potentiate an increase in bleeding time caused by acetylsalicylic acid (150 mg).
Sildenafil (50 mg) does not potentiate the hypotensive effect of alcohol in healthy volunteers with a maximum blood alcohol content of 80 mg / dl.
Generalization of available data for the following drugs: diuretics, beta-blockers, ACE inhibitors, angiotensin receptor blockers, vasodilators and central antihypertensive agents, adrenergic neuron blockers, BKK and alpha-adrenergic blockers, did not reveal differences in patients profile, adverse taking sildenafil or placebo at the same time. In a specially conducted study, sildenafil (100 mg) was used simultaneously with amlodipine in patients with arterial hypertension and additionally lowered SBP in the supine position by an average of 8 mm Hg. Art., and DBP - 7 mm RT. Art. This additional decrease in blood pressure turned out to be the same as when using only sildenafil in healthy volunteers.
Overdose
Symptoms: headache, blood tides to the skin, dizziness, dyspepsia, nasal congestion, visual impairment.
Treatment: symptomatic. Hemodialysis is not effective.
Storage conditions
At a temperature not exceeding 30 РC, in the original packaging.
Keep out of the reach and sight of children.
Active ingredient
Sildenafil
Terms leave through pharmacies
Prescription
The dosage form of
tablet
KRKA d.d. Novo mesto AO, Slovenia
tablets
Packing
4 pcs.
Pharmacological action
Pharmacological action - restoring erectile function, vasodilating.
Sildenafil is a potent selective inhibitor of cGMP-specific PDE-5. Restores impaired erectile function by increasing blood flow to the penis.
The physiological process that underlies penile erection involves the release of nitric oxide (NO) in the cavernous body through sexual stimulation. NO activates the guanylate cyclase enzyme and increases the content of cGMP, which relaxes the smooth muscle cells of the cavernous body and helps to fill it with blood.
Sildenafil has a peripheral effect on erection. It does not have a direct relaxing effect on an isolated human cavernous body, but enhances the relaxing effect of NO. When the NO / cGMP connection is activated, which occurs under the influence of sexual stimuli, the inhibition of PDE-5 by sildenafil leads to an increase in cGMP in the cavernous body. Thus, for the development of the desired pharmacological action of sildenafil, sexual stimulation is necessary. In vitro studies have shown that sildenafil is selective for PDE-5, which is involved in the development of an erection. Its activity against PDE-5 is superior to activity against other known PDE. It is 10 times less effective with respect to PDE-6, which takes part in retinal photo transmission. At the maximum recommended doses, it is 80 times less selective for PDE-1, 700 times for PDE-2, 3, 4, 7, 8, 9, 10 and 11.
Sildenafil activity in relation to PDE-5 is about 4000 times superior to its activity against PDE-3, a cAMP-specific PDE involved in heart contraction.
Sildenafil causes a small and transient decrease in blood pressure, which in most cases has no clinical manifestations. The average maximum decrease in SBP in the supine position, after taking sildenafil inside at a dose of 100 mg, is 8.4 mm RT. Art. The corresponding change in blood pressure is 5.5 mm RT. Art. This decrease in blood pressure is due to the vasodilating properties of sildenafil, possibly associated with an increase in the level of cGMP in vascular smooth muscle cells. A single oral intake of sildenafil in a dose of up to 100 mg was not accompanied by clinically significant changes in the ECG in healthy volunteers.
Sildenafil does not affect cardiac output and does not alter blood flow through stenosed arteries.
Contraindications
Hypersensitivity to sildenafil or any other component of the
preparation Simultaneous administration with NO donors (such as amyl nitrite) or nitrates in any form (given the known effect of sildenafil on NO / cGMP, sildenafil may enhance the hypotensive effect) who are not recommended for sexual activity (for example, patients with severe cardiovascular diseases such as unstable angina or severe heart failure)
Patients with low vision due to anterior ischemic optic neuropathy of non-arterial origin (NAION), whether or not it is associated with the use of PDE-5 inhibitors
Severe hepatic dysfunction
Arterial hypotension (blood pressure less than 90/50 mm Hg)
Recent stroke or myocardial infarction
naya congenital retinal dystrophy (including retinitis pigmentosa (retinitis pigmentosa)
age of 18
As registered indications VizarsinВ® drug is not intended for use in women
Precautions:.. lactose intolerance, lactase deficiency, glucose-galactose malabsorption syndrome CCC syndrome multiple systemic atrophy anatomical deformation of the penis priapism sickle cell anemia multiple myeloma leukemia simultaneous administration of alpha-blockers.
Use during pregnancy and lactation
According to the registered indication, the drug Vizarsin® is not intended for use in women.
Special instructions
Before prescribing drug therapy, you need to carefully evaluate the history and conduct a clinical examination to diagnose erectile dysfunction and identify its possible causes.
Sexual activity poses a certain risk in the presence of CVD diseases, therefore, before starting any therapy for erectile dysfunction, the doctor must evaluate the patient's condition. Sildenafil has a systemic vasodilator effect, leading to a small and transient decrease in blood pressure. Before using sildenafil, the doctor should carefully assess the risk of possible unwanted vasodilating effects in patients with relevant diseases, especially against the background of sexual activity. Increased susceptibility to vasodilators is observed in patients with left ventricular outflow tract obstruction (e.g. aortic stenosis, hypertrophic obstructive cardiomyopathy), as well as a rare syndrome of multiple systemic atrophy, which manifests itself as a severe violation of the autonomous regulation of blood pressure.
VizarsinВ® enhances the hypotensive effect of nitrates.
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 cardiovascular risk factors. Many of the noted phenomena developed within a short period of time after taking sildenafil, even in the absence of sexual activity. It is impossible to determine exactly whether these phenomena are directly related to the described or other factors.
Preparations for treating sexual dysfunction, including sildenafil, 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).
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.
With the use of sildenafil and other PDE-5 inhibitors, cases of visual impairment and the development of anterior ischemic optic neuropathy of non-arterial origin were noted. Patients should be informed that in case of loss of vision or its sudden deterioration, it is necessary to stop using VisarsinВ® and consult a doctor immediately.
Sildenafil should be used with caution in patients taking alpha-blockers, since the combined use of sildenafil and alpha-blockers can lead to symptomatic hypotension in some susceptible patients. Arterial hypotension most often develops 4 hours after the use of sildenafil. To minimize the risk of developing postural hypotension in these patients, sildenafil should only be taken after hemodynamic stabilization is achieved while taking alpha-blockers. Reception of sildenafil should be begun with a dose of 25 mg (see. "Indications"). In addition, the doctor should explain to the patient what can be done if hypotension develops.
Studies with human platelets have shown that sildenafil potentiates the anticoagulant effect of sodium nitroprusside in vitro. 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 careful assessment of the benefit / risk ratio.
VisarsinВ® contains lactose, in this connection, when using the drug, caution should be exercised in patients with lactose intolerance, lactase deficiency, glucose-galactose malabsorption syndrome.
VizarsinВ® is not intended for use in women.
Influence on the ability to drive vehicles and work with mechanisms. No studies have been conducted to study the effect on the ability to drive vehicles and work with mechanisms, but because of the possibility of visual impairment, dizziness, patients should evaluate the individual reaction to taking VisarsinВ®, especially at the beginning of treatment and when changing the dosage regimen.
Composition
1 tablet contains: active substance: sildenafil 50 mg
excipients: microcrystalline cellulose (Avicel PH101), calcium dihydrogen phosphate, croscarmellose sodium, hypromellose, microcrystalline cellulose (Avicel PH102 magnesium).
Dosage and Administration
Inside.
The recommended dose is 50 mg / day, which is taken if necessary, approximately 1 hour before the alleged sexual activity. Depending on the effectiveness and tolerability, the dose of the drug Visarsin® can be increased to 100 mg / day or reduced to 25 mg / day. The maximum recommended dose is 100 mg / day. The maximum recommended frequency of use of the drug is 1 time per day. When using the drug Vizarsin® with food, the effect of the drug may develop later than when using it on an empty stomach.
Special patient groups
Elderly patients. Vizarsin® dose adjustment is not required.
Impaired renal function. With mild and moderate severity of renal failure (Clcreatinin 30–80 ml / min) dose adjustment is not required, in severe renal failure (Cl creatinine less than 30 ml / min), the dose of the drug Vizarsin® should be reduced to 25 mg / day.
Impaired liver function. For patients with impaired liver function (e.g. cirrhosis), the dose is 25 mg / day.
Simultaneous use with other drugs
When used simultaneously with ritonavir, the maximum single dose of the drug Vizarsin® should not exceed 25 mg, and the frequency of use should be 1 time in 48 hours.
To reduce the likelihood of developing orthostatic hypotension, it is necessary to achieve a stable state during alpha therapy adrenoblockers before starting the use of sildenafil.
Side effects of
On the part of the immune system: rarely, hypersensitivity reactions.
From the nervous system: very often - headache often - dizziness infrequently - drowsiness, hypesthesia rarely - cerebrovascular events, fainting frequency unknown - transient ischemic attacks, convulsions.
On the part of the organs of vision: often - visual impairment, transient color perception disorders (chromatopsy) infrequently - conjunctival damage, impaired lacrimal formation frequency unknown - NAION, occlusion of the blood vessels of the fibers, narrowing of the visual fields.
On the part of the organ of hearing and the labyrinth: infrequently - dizziness, tinnitus rarely - deafness *.
From the CCC: often - flushing of the skin of the face infrequently - palpitations, tachycardia rarely - arterial hypertension, arterial hypotension, myocardial infarction, atrial fibrillation, frequency unknown - ventricular arrhythmia, unstable angina, sudden cardiac arrest.
From the respiratory system: often - nasal congestion rarely - nosebleeds.
From the digestive system: often - dyspepsia infrequently - vomiting, nausea, dry mouth.
From the skin: infrequently - a skin rash.
From the side of the musculoskeletal system: infrequently - myalgia.
From the reproductive system: frequency is unknown - priapism, prolonged erection.
General disorders and changes at the injection site: infrequently - chest pain, general weakness.
* Sudden hearing loss or loss was noted in a small number of cases during post-marketing use or during clinical trials of all PDE-5 inhibitors, including sildenafil.
Drug interaction
Effect of other drugs on the pharmacokinetics of sildenafil
In vitro studies. Sildenafil metabolism occurs mainly under the influence of cytochrome P450 (CYP) 3A4 isoenzymes (main pathway) and 2C9 (additional pathway), therefore, inhibitors of these isoenzymes can reduce sildenafil clearance, and inductors, respectively, increase sildenafil clearance.
In vivo studies. The simultaneous use of inhibitors of the CYP3A4 isoenzyme (such as ketoconazole, erythromycin, cimetidine) and sildenafil reduces its clearance.
Ritonavir increases the AUC of sildenafil by 11 times, the combined use of these drugs is not recommended.
With the simultaneous use of sildenafil (100 mg 1 time / day) and an HIV protease inhibitor and a CYP3A4 isoenzyme inhibitor saquinavir, while achieving a constant concentration of saquinavir in the blood (1200 mg 3 times a day), Cmax of sildenafil increases by 140%, and AUC - 210%. Sildenafil does not affect the pharmacokinetics of saquinavir. Stronger inhibitors of the CYP3A4 isoenzyme, such as ketoconazole and itraconazole, are thought to cause more pronounced changes in the pharmacokinetics of sildenafil.
The use of 100 mg of sildenafil 1 time / day together with erythromycin, a specific inhibitor of СУР3А4, against the background of achieving a constant concentration of erythromycin in the blood (500 mg 2 times / day for 5 days) leads to an increase in AUC of sildenafil by 182%. In healthy male volunteers, azithromycin (500 mg / day for 3 days) did not affect AUC, Cmax, Tmax, excretion rate constant, and T1 / 2 of sildenafil or its main circulating metabolite. Cimetidine (800 mg), a non-specific inhibitor of CYP3A4, when taken together with sildenafil (50 mg) by healthy volunteers caused an increase in plasma sildenafil concentration by 56%.
Grapefruit juice, a weak inhibitor of CYP3A4, can moderately increase plasma concentrations of sildenafil.
Single use of antacids (magnesium hydroxide / aluminum hydroxide) does not affect the bioavailability of sildenafil.
Although special pharmacokinetic studies with all drugs have not been conducted, Population pharmacokinetic analysis did not reveal a change in the pharmacokinetics of sildenafil when used simultaneously with inhibitors of the CYP2C9 isoenzyme such as tolbutamide, warfarin, phenytoin, with inhibitors of the CYP2D6 isoenzyme (SSRIs and tricyclic antidepressants, tyazide and similar diuretics, diuretic and diuretic diuretics, diuretics, and diuretic diuretics beta-blockers or inducers of CYP450 isoenzymes (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 serious interactions with sildenafil.
Effect of sildenafil on other drugs
In vitro studies. Sildenafil is a weak inhibitor of cytochrome P450 isoenzymes 1A2, 2C9, 2C19, 2D6, 2E1 and 3A4 (IC50 - 150 μmol). When using sildenafil at recommended doses, its Cmax in blood plasma is about 1 μmol, therefore, it is unlikely that Vizarsin® can affect the clearance of substrates of these isoenzymes.
No data are available on the interaction of sildenafil with non-specific PDE inhibitors such as theophylline or dipyridamole.
In vivo studies. Given the known effect of sildenafil on NO / cGMP, it can enhance the hypotensive effect of nitrates, so its simultaneous use with NO donors or nitrates in any form is contraindicated.
The simultaneous use of sildenafil and alpha-blockers can lead to symptomatic arterial hypotension in some 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 with stable hemodynamics while taking doxazosin (4 and 8 mg), sildenafil (25, 50 or 100 mg) was used simultaneously. In all three studies, an average additional decrease in blood pressure was observed in the supine position at 7/7 mm Hg. Art., 9/5 mm RT. Art. and 8/4 mm RT. Art., and an additional decrease in blood pressure in a standing position at 6/6 mm RT. Art., 11/4 mm RT. Art. and 4/5 mm RT. Art. respectively. With the simultaneous use of sildenafil and doxazosin in patients with stable hemodynamics while taking doxazosin, rare cases of the development of symptomatic postural hypotension have been noted. In these described cases, dizziness or a feeling of lightness developed, but without the development of fainting conditions.
No significant interactions were observed with the simultaneous use of sildenafil (50 mg) and tolbutamide (250 mg) or warfarin (40 mg), which are metabolized with CYP2C9.
Sildenafil (50 mg) does not potentiate an increase in bleeding time caused by acetylsalicylic acid (150 mg).
Sildenafil (50 mg) does not potentiate the hypotensive effect of alcohol in healthy volunteers with a maximum blood alcohol content of 80 mg / dl.
Generalization of available data for the following drugs: diuretics, beta-blockers, ACE inhibitors, angiotensin receptor blockers, vasodilators and central antihypertensive agents, adrenergic neuron blockers, BKK and alpha-adrenergic blockers, did not reveal differences in patients profile, adverse taking sildenafil or placebo at the same time. In a specially conducted study, sildenafil (100 mg) was used simultaneously with amlodipine in patients with arterial hypertension and additionally lowered SBP in the supine position by an average of 8 mm Hg. Art., and DBP - 7 mm RT. Art. This additional decrease in blood pressure turned out to be the same as when using only sildenafil in healthy volunteers.
Overdose
Symptoms: headache, blood tides to the skin, dizziness, dyspepsia, nasal congestion, visual impairment.
Treatment: symptomatic. Hemodialysis is not effective.
Storage conditions
At a temperature not exceeding 30 РC, in the original packaging.
Keep out of the reach and sight of children.
Active ingredient
Sildenafil
Terms leave through pharmacies
Prescription
The dosage form of
tablet
KRKA d.d. Novo mesto AO, Slovenia
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