VIAGRA VGR 25 Pill: blue, four-sided

Viagra > 25 mg viagra


The use of VIAGRA offers no protection against sexually transmitted diseases. Counseling of patients about the protective measures necessary to guard against sexually transmitted diseases, including the Human Immunodeficiency Virus (HIV), may be considered. Sildenafil metabolism is principally mediated by the cytochrome P450 (CYP) isoforms 3A4 (major route) and 2C9 (minor route). Therefore, inhibitors of these isoenzymes may reduce sildenafil clearance and inducers of these isoenzymes may increase sildenafil clearance.

Adult Dosing .

Given sildenafil peak plasma concentrations of approximately 1 µM after recommended doses, it is unlikely that viagra vardenafil 20mg VIAGRA will alter the clearance of substrates of these isoenzymes. Three double-blind, placebo-controlled, randomized, two-way crossover studies were conducted to assess the interaction of VIAGRA with doxazosin, an alpha-adrenergic blocking agent. In the first study, a single oral dose of VIAGRA 100 mg or matching placebo was administered in a 2-period crossover design to 4 generally healthy males with benign prostatic hyperplasia (BPH). Following at least 14 consecutive daily doses of doxazosin, VIAGRA 100 mg or matching placebo was administered simultaneously with doxazosin. Following a review of the data from these first 4 subjects (details provided below), the VIAGRA dose was reduced to 25 mg.

Oral Administration

Thereafter, 17 subjects were treated with VIAGRA 25 mg or matching placebo in combination with doxazosin 4 mg (15 subjects) or doxazosin 8mg (2 subjects). The mean subject age was 66.5 years. For the 17 subjects who received VIAGRA 25 mg and matching placebo, the placebo-subtracted mean maximum decreases from baseline (95% CI) in systolic blood pressure were as follows: Blood pressure was measured immediately pre-dose and at 15, 30, 45 minutes, and 1, 1.5, 2, 2.5, 3, 4, 6 and 8 hours after VIAGRA or matching placebo. Outliers were defined as subjects with a standing systolic blood pressure of less than 85 mmHg or a decrease from baseline in standing systolic blood pressure of greater than 30 mmHg at one or more timepoints. There were no subjects treated with VIAGRA 25 mg who had a standing SBP less than 85mmHg. Cimetidine (800 mg), a nonspecific CYP inhibitor, caused a 56% increase in plasma sildenafil concentrations when coadministered with VIAGRA (50 mg) to healthy volunteers. When a single 100 mg dose of VIAGRA was administered with erythromycin, a specific CYP3A4 inhibitor, at steady state (500 mg bid for 5 days), there was a 182% increase in sildenafil systemic exposure (AUC). In addition, in a study performed in healthy male volunteers, coadministration of the HIV protease inhibitor saquinavir, also a CYP3A4 inhibitor, at steady state (1200 mg tid) with VIAGRA (100 mg single dose) resulted in a 140% increase in sildenafil Cmax and a 210% increase in sildenafil AUC.

Product Dosage Quantity + Bonus Price
Viagra Generic25mg20 Pills37.74€ 35.94€
Viagra Soft Tabs100mg20 Pills62.99€ 59.99€
Viagra Soft Tabs100mg90 + 6 Pills205.31€ 195.53€
Viagra Generic50mg20 Pills40.52€ 38.59€
Viagra Original100mg92 + 4 Pills362.88€ 345.60€
Viagra Generic50mg90 + 6 Pills107.37€ 102.26€
Viagra Soft Tabs100mg180 + 10 Pills314.95€ 299.95€
Viagra Generic100mg10 Pills28.91€ 27.53€
Viagra Generic100mg20 Pills45.58€ 43.41€
Viagra Oral Jelly100mg220 + 18 Sachets562.28€ 535.50€
Viagra Original100mg12 Pills72.54€ 69.09€
Viagra Generic200mg90 + 6 Pills170.79€ 162.66€
Viagra Generic25mg360 + 10 Pills213.68€ 203.50€
Viagra Generic25mg30 + 4 Pills47.97€ 45.69€
Viagra Super Active100mg20 + 4 Pills48.05€ 45.76€

VIAGRA had no effect on saquinavir pharmacokinetics.

What side effects could I expect?

At 24 hours the plasma levels of sildenafil were still approximately 200 ng/mL, compared to approximately 5 ng/mL when sildenafil was dosed alone. This is consistent with ritonavir's marked effects on a broad range of P450 substrates. VIAGRA had no effect on ritonavir pharmacokinetics (see DOSAGE AND ADMINISTRATION ). Although the interaction between other protease inhibitors and sildenafil has not been studied, their concomitant use is expected to increase sildenafil levels. In a study of healthy male volunteers, co-administration of sildenafil at steady state (80 mg t.i.d.) with endothelin receptor antagonist bosentan (a moderate inducer of CYP3A4, CYP2C9 and possibly of cytochrome P450 2C19) at steady state (125 mg b.i.d.) resulted in a 63% decrease of sildenafil AUC and a 55% decrease in sildenafil Cmax.

Pregnancy Precautions

Concomitant administration of strong CYP3A4 inducers, such as rifampin, is expected to cause greater decreases in plasma levels of sildenafil. Single doses of antacid (magnesium hydroxide/aluminum hydroxide) did not affect the bioavailability of VIAGRA. Pharmacokinetic data from patients in clinical trials showed no effect on sildenafil pharmacokinetics of CYP2C9 inhibitors (such as tolbutamide, warfarin), CYP2D6 inhibitors (such as selective serotonin reuptake inhibitors, tricyclic antidepressants), thiazide and related diuretics, ACE inhibitors, and calcium channel blockers. The AUC of the active metabolite, N-desmethyl sildenafil, was increased 62% by loop and potassium-sparing diuretics and 102% by nonspecific beta-blockers. These effects on the metabolite are not expected to be of clinical consequence. Stronger CYP3A4 inhibitors such as ketoconazole or itraconazole would be expected to have still greater effects, and population data from patients in clinical trials did indicate a reduction in sildenafil clearance when it was coadministered with CYP3A4 inhibitors (such as ketoconazole, erythromycin, or cimetidine) (see DOSAGE AND ADMINISTRATION ).

Condition or Medication Why It Matters Alternatives
Nitrate medication Can cause dangerous hypotension Use other ED treatments
Severe heart disease Increased risk of cardiovascular events Non-pharmacological methods
Liver impairment Altered drug metabolism Lower doses or different medications

In another study in healthy male volunteers, coadministration with the HIV protease inhibitor ritonavir, which is a highly potent P450 inhibitor, at steady state (500 mg bid) with VIAGRA (100 mg single dose) resulted in a 300% (4-fold) increase in sildenafil Cmax and a 1000% (11-fold) increase in sildenafil plasma AUC. At 24 hours the plasma levels of sildenafil were still approximately 200 ng/mL, compared to approximately 5 ng/mL when sildenafil was dosed alone.

Related topics

There were three subjects with a decrease from baseline in standing systolic BP greater than 30mmHg following VIAGRA 25 mg, one subject with a decrease from baseline in standing systolic BP greater than 30 mmHg following placebo and two subjects with a decrease from baseline in standing systolic BP greater than 30 mmHg following both VIAGRA and placebo. No severe adverse events potentially related to blood pressure effects were reported in this group. Of the four subjects who received VIAGRA 100 mg in the first part of this study, a severe adverse event related to blood pressure effect was reported in one patient (postural hypotension that began 35 minutes after dosing with VIAGRA with symptoms lasting for 8 hours), and mild adverse events potentially related to blood pressure effects were reported in two others (dizziness, headache and fatigue at 1 hour after dosing; and dizziness, lightheadedness and nausea at 4 hours after dosing). There were no reports of syncope among these patients. For these four subjects, the placebo-subtracted mean maximum decreases from baseline in supine and standing systolic blood pressures were 14.8 mmHg and 21.5 mmHg, respectively.

Dosage adjustments

Two of these subjects had a standing SBP less than 85mmHg. Both of these subjects were protocol violators, one due to a low baseline standing SBP, and the other due to baseline orthostatic hypotension. In the second study, a single oral dose of VIAGRA 50 mg or matching placebo was administered in a 2-period crossover design to 20 generally healthy males with BPH. Following at least 14 consecutive days of doxazosin, VIAGRA 50mg or matching placebo was administered simultaneously with doxazosin 4 mg (17 subjects) or with doxazosin 8 mg (3 subjects). The mean subject age in this study was 63.9 years. This is consistent with ritonavir's marked effects on a broad range of P450 substrates. VIAGRA had no effect on ritonavir pharmacokinetics (see DOSAGE AND ADMINISTRATION ). Although the interaction between other protease inhibitors and sildenafil has not been studied, their concomitant use is expected to increase sildenafil levels. In a study of healthy male volunteers, co-administration of sildenafil at steady state (80 mg t.i.d.) with endothelin receptor antagonist bosentan (a moderate inducer of CYP3A4, CYP2C9 and possibly of cytochrome P450 2C19) at steady state (125 mg b.i.d.) resulted in a 63% decrease of sildenafil AUC and a 55% decrease in sildenafil Cmax. Concomitant administration of strong CYP3A4 inducers, such as rifampin, is expected to cause greater decreases in plasma levels of sildenafil. Single doses of antacid (magnesium hydroxide/aluminum hydroxide) did not affect the bioavailability of VIAGRA. Pharmacokinetic data from patients in clinical trials showed no effect on sildenafil pharmacokinetics of CYP2C9 inhibitors (such as tolbutamide, warfarin), CYP2D6 inhibitors (such as selective serotonin reuptake inhibitors, tricyclic antidepressants), thiazide and related diuretics, ACE inhibitors, and calcium channel blockers. The AUC of the active metabolite, N-desmethyl sildenafil, was increased 62% by loop and potassium-sparing diuretics and 102% by nonspecific beta-blockers. These effects on the metabolite are not expected to be of clinical consequence. Given sildenafil peak plasma concentrations of approximately 1 µM after recommended doses, it is unlikely that viagra vardenafil 20mg VIAGRA will alter the clearance of substrates of these isoenzymes. Three double-blind, placebo-controlled, randomized, two-way crossover studies were conducted to assess the interaction of VIAGRA with doxazosin, an alpha-adrenergic blocking agent. In the first study, a single oral dose of VIAGRA 100 mg or matching placebo was administered in a 2-period crossover design to 4 generally healthy males with benign prostatic hyperplasia (BPH). Following at least 14 consecutive daily doses of doxazosin, VIAGRA 100 mg or matching placebo was administered simultaneously with doxazosin. Following a review of the data from these first 4 subjects (details provided below), the VIAGRA dose was reduced to 25 mg. Thereafter, 17 subjects were treated with VIAGRA 25 mg or matching placebo in combination with doxazosin 4 mg (15 subjects) or doxazosin 8mg (2 subjects).

  • The safety profile of 25 mg Viagra is well-studied with low incidence of serious side effects.
  • Patients should schedule follow-up appointments to monitor response.
  • It is important to consider interactions with medications like antihypertensives.
  • Take note of any allergic reactions such as rash or swelling.
  • Some men may achieve optimal results by adjusting the dose under supervision.
  • Do not share Viagra with others, as it can cause adverse effects in certain individuals.
  • Combining Viagra with nitrates can cause dangerous drops in blood pressure.

The mean subject age was 66.5 years. For the 17 subjects who received VIAGRA 25 mg and matching placebo, the placebo-subtracted mean maximum decreases from baseline (95% CI) in systolic blood pressure were as follows: Blood pressure was measured immediately pre-dose and at 15, 30, 45 minutes, and 1, 1.5, 2, 2.5, 3, 4, 6 and 8 hours after VIAGRA or matching placebo.

What is Viagra?

Twenty subjects received VIAGRA 50 mg, but only 19 subjects received matching placebo. One patient discontinued the study prematurely due to an adverse event of hypotension following dosing with VIAGRA 50 mg. This patient had been taking minoxidil, a potent vasodilator, during the study. For the 19 subjects who received both VIAGRA and matching placebo, the placebo-subtracted mean maximum decreases from baseline (95% CI) in systolic blood pressure were as follows: Blood pressure was measured after administration of VIAGRA at the same times as those specified for the first doxazosin study. There were two subjects who had a standing SBP of viagra sildenafil price less than 85 mmHg.

When is the best time to take Viagra?

In these two subjects, hypotension was reported as a moderately severe adverse event, beginning at approximately 1 hour after administration of VIAGRA 50 mg and resolving after approximately 7.5 hours. There was one subject with a decrease from baseline in standing systolic BP greater than 30mmHg following VIAGRA 50 mg and one subject with a decrease from baseline in standing systolic BP greater than 30 mmHg following both VIAGRA 50 mg and placebo. There were no severe adverse events potentially related to blood pressure and no episodes of syncope reported in this study. In the third study, a single oral dose of VIAGRA 100 mg or matching placebo was administered in a 3-period crossover design to 20 generally healthy males with BPH. In dose period 1, subjects were administered open-label doxazosin and a single dose of VIAGRA 50 mg simultaneously, after at least 14 consecutive days of doxazosin. Outliers were defined as subjects with a standing systolic blood pressure of less than 85 mmHg or a decrease from baseline in standing systolic blood pressure of greater than 30 mmHg at one or more timepoints. There were no subjects treated with VIAGRA 25 mg who had a standing SBP less than 85mmHg. There were three subjects with a decrease from baseline in standing systolic BP greater than 30mmHg following VIAGRA 25 mg, one subject with a decrease from baseline in standing systolic BP greater than 30 mmHg following placebo and two subjects with a decrease from baseline in standing systolic BP greater than 30 mmHg following both VIAGRA and placebo. No severe adverse events potentially related to blood pressure effects were reported in this group. Of the four subjects who received VIAGRA 100 mg in the first part of this study, a severe adverse event related to blood pressure effect was reported in one patient (postural hypotension that began 35 minutes after dosing with VIAGRA with symptoms lasting for 8 hours), and mild adverse events potentially related to blood pressure effects were reported in two others (dizziness, headache and fatigue at 1 hour after dosing; and dizziness, lightheadedness and nausea at 4 hours after dosing). There were no reports of syncope among these patients. For these four subjects, the placebo-subtracted mean maximum decreases from baseline in supine and standing systolic blood pressures were 14.8 mmHg and 21.5 mmHg, respectively. Two of these subjects had a standing SBP less than 85mmHg. Both of these subjects were protocol violators, one due to a low baseline standing SBP, and the other due to baseline orthostatic hypotension. In the second study, a single oral dose of VIAGRA 50 mg or matching placebo was administered in a 2-period crossover design to 20 generally healthy males with BPH. Following at least 14 consecutive days of doxazosin, VIAGRA 50mg or matching placebo was administered simultaneously with doxazosin 4 mg (17 subjects) or with doxazosin 8 mg (3 subjects). The mean subject age in this study was 63.9 years.

How to take Viagra 100mg tablets?

The use of VIAGRA offers no protection against sexually transmitted diseases. Counseling of patients about the protective measures necessary to guard against sexually transmitted diseases, including the Human Immunodeficiency Virus (HIV), may be considered. Sildenafil metabolism is principally mediated by the cytochrome P450 (CYP) isoforms 3A4 (major route) and 2C9 (minor route). Therefore, inhibitors of these isoenzymes may reduce sildenafil clearance and inducers of these isoenzymes may increase sildenafil clearance. Cimetidine (800 mg), a nonspecific CYP inhibitor, caused a 56% increase in plasma sildenafil concentrations when coadministered with VIAGRA (50 mg) to healthy volunteers.

How is sildenafil supplied (dosage forms)?

When a single 100 mg dose of VIAGRA was administered with erythromycin, a specific CYP3A4 inhibitor, at steady state (500 mg bid for 5 days), there was a 182% increase in sildenafil systemic exposure (AUC). In addition, in a study performed in healthy male volunteers, coadministration of the HIV protease inhibitor saquinavir, also a CYP3A4 inhibitor, at steady state (1200 mg tid) with VIAGRA (100 mg single dose) resulted in a 140% increase in sildenafil Cmax and a 210% increase in sildenafil AUC. VIAGRA had no effect on saquinavir pharmacokinetics. Stronger CYP3A4 inhibitors such as ketoconazole or itraconazole would be expected to have still greater effects, and population data from patients in clinical trials did indicate a reduction in sildenafil clearance when it was coadministered with CYP3A4 inhibitors (such as ketoconazole, erythromycin, or cimetidine) (see DOSAGE AND ADMINISTRATION ). In another study in healthy male volunteers, coadministration with the HIV protease inhibitor ritonavir, which is a highly potent P450 inhibitor, at steady state (500 mg bid) with VIAGRA (100 mg single dose) resulted in a 300% (4-fold) increase in sildenafil Cmax and a 1000% (11-fold) increase in sildenafil plasma AUC. Twenty subjects received VIAGRA 50 mg, but only 19 subjects received matching placebo.

Membership Benefits

If a subject did not successfully complete this first dosing period, he was discontinued from the study. Subjects who had successfully completed the previous doxazosin interaction study (using VIAGRA 50 mg), including no significant hemodynamic adverse events, were allowed to skip dose period 1. Treatment with doxazosin continued for at least 7 days after dose period 1. Thereafter, VIAGRA 100mg or matching placebo was administered simultaneously with doxazosin 4 mg (14 subjects) or doxazosin 8 mg (6 subjects) in standard crossover fashion. The mean subject age in this study was 66.4 years.

Common Adverse Effects

Two were discontinued after study period 1: one failed to meet pre-dose screening qualifications and the other experienced symptomatic hypotension as a moderately severe adverse event 30 minutes after dosing with open-label VIAGRA 50 mg. Of the twenty subjects who were ultimately assigned to treatment, a total of 13 subjects successfully completed dose period 1, and seven had successfully completed the previous doxazosin study (using VIAGRA 50 mg). For the 20 subjects who received VIAGRA 100 mg and matching placebo, the placebo-subtracted mean maximum decreases from baseline (95% CI) in systolic blood pressure were as follows: Blood pressure was measured after administration of VIAGRA at the same times as those specified for the previous doxazosin studies. There were three subjects who had a standing SBP of less than 85 mmHg. All three were taking VIAGRA 100 mg, and all three reported mild adverse events at the time of reductions in standing SBP, including vasodilation and lightheadedness. One patient discontinued the study prematurely due to an adverse event of hypotension following dosing with VIAGRA 50 mg. This patient had been taking minoxidil, a potent vasodilator, during the study. For the 19 subjects who received both VIAGRA and matching placebo, the placebo-subtracted mean maximum decreases from baseline (95% CI) in systolic blood pressure were as follows: Blood pressure was measured after administration of VIAGRA at the same times as those specified for the first doxazosin study. There were two subjects who had a standing SBP of viagra sildenafil price less than 85 mmHg. In these two subjects, hypotension was reported as a moderately severe adverse event, beginning at approximately 1 hour after administration of VIAGRA 50 mg and resolving after approximately 7.5 hours. There was one subject with a decrease from baseline in standing systolic BP greater than 30mmHg following VIAGRA 50 mg and one subject with a decrease from baseline in standing systolic BP greater than 30 mmHg following both VIAGRA 50 mg and placebo. There were no severe adverse events potentially related to blood pressure and no episodes of syncope reported in this study. In the third study, a single oral dose of VIAGRA 100 mg or matching placebo was administered in a 3-period crossover design to 20 generally healthy males with BPH. In dose period 1, subjects were administered open-label doxazosin and a single dose of VIAGRA 50 mg simultaneously, after at least 14 consecutive days of doxazosin.

  • Generic versions of 25 mg Viagra are available and usually cheaper.
  • Always purchase Viagra from reputable pharmacies to avoid counterfeit products.
  • Combining Viagra with other ED medications is not recommended.
  • Be aware of potential interactions if taking other prescription drugs.
  • The efficacy of 25 mg Viagra can vary based on individual health factors.
  • Use Viagra only as directed by a healthcare provider.
  • Do not take Viagra if you have been advised against sexual activity for health reasons.

If a subject did not successfully complete this first dosing period, he was discontinued from the study.

  • 25 mg Viagra may be recommended for men with mild to moderate ED.
  • The medication’s effects typically last around 4-6 hours.
  • Missing a dose is not typical since Viagra is used as needed.
  • To maximize safety, inform your doctor of all health conditions.
  • Patients should avoid grapefruit or grapefruit juice when taking Viagra.
  • Ensure adequate hydration when using Viagra to prevent dehydration.
  • Follow up with your doctor if Viagra doesn't produce expected results.

Subjects who had successfully completed the previous doxazosin interaction study (using VIAGRA 50 mg), including no significant hemodynamic adverse events, were allowed to skip dose period 1.

Country Legal Classification Over-the-counter (OTC) Prescription Required Notes
USA Prescription-only No Yes Controlled medication
UK Prescription-only No Yes Available at pharmacies with prescription
Australia Prescription-only No Yes Restricted sale

Treatment with doxazosin continued for at least 7 days after dose period 1. Thereafter, VIAGRA 100mg or matching placebo was administered simultaneously with doxazosin 4 mg (14 subjects) or doxazosin 8 mg (6 subjects) in standard crossover fashion. The mean subject age in this study was 66.4 years. Two were discontinued after study period 1: one failed to meet pre-dose screening qualifications and the other experienced symptomatic hypotension as a moderately severe adverse event 30 minutes after dosing with open-label VIAGRA 50 mg. Of the twenty subjects who were ultimately assigned to treatment, a total of 13 subjects successfully completed dose period 1, and seven had successfully completed the previous doxazosin study (using VIAGRA 50 mg). For the 20 subjects who received VIAGRA 100 mg and matching placebo, the placebo-subtracted mean maximum decreases from baseline (95% CI) in systolic blood pressure were as follows: Blood pressure was measured after administration of VIAGRA at the same times as those specified for the previous doxazosin studies.

Therapeutic indication

Can Viagra make sex last longer?

There were three subjects who had a standing SBP of less than 85 mmHg. All three were taking VIAGRA 100 mg, and all three reported mild adverse events at the time of reductions in standing SBP, including vasodilation and lightheadedness.

© 2021 Gastroenterologie im Zentrum, Kasernenstrasse 1, 8180 Bülach, Tel 044 864 19 18, Fax 044 864 19 17