Viagra 100mg (Sildenafil) 4 Tablets

Sildenafil citrate, USP is a white to off-white crystalline powder with a solubility of 3.5 mg/mL in water and a molecular weight of 666.7. Sildenafil tablets USP are formulated as pale blue to blue film-coated tablets equivalent to 25 mg, 50 mg and 100 mg of sildenafil for oral administration.

• Sildenafil citrate 100mg tablets are FDA-approved for erectile dysfunction.
• It’s important to adhere to the prescribed timetable to ensure safety.
• Not suitable for those with severe heart or liver issues without consulting a doctor.
• Use sildenafil with caution if you have a history of stroke or cardiovascular disease.
• The medication enhances natural erectile responses, not sexual desire.
• Avoid grapefruit or grapefruit juice while taking sildenafil due to interactions.
• Patients should avoid combining sildenafil with recreational drugs.
• Some users may experience back pain or muscle aches as side effects.
• Always read the patient information leaflet before use.
• Report any side effects or unusual symptoms to your healthcare provider.
• Pregnant or breastfeeding women should avoid using sildenafil.
• Sildenafil is only effective when sexual stimulation occurs.

12 CLINICAL PHARMACOLOGY 12.1 Mechanism of ActionThe physiologic mechanism of erection of the penis involves release of nitric oxide (NO) in the corpus cavernosum during sexual stimulation.

NO then activates the enzyme guanylate cyclase, which results in increased levels of cyclic guanosine monophosphate (cGMP), producing smooth muscle relaxation in the corpus cavernosum and allowing inflow of blood.Sildenafil enhances the effect of NO by inhibiting phosphodiesterase type 5 (PDE5), which is responsible for degradation of cGMP in the corpus cavernosum.

Before taking this medicine

When sexual stimulation causes local release of NO, inhibition of PDE5 by sildenafil causes increased levels of cGMP in the corpus cavernosum, resulting in smooth muscle relaxation and inflow of blood to the corpus cavernosum. Sildenafil at recommended doses has no effect in the absence of sexual stimulation.Binding CharacteristicsStudies in vitrohave shown that sildenafil is selective for PDE5. Its effect is more potent on PDE5 than on other known phosphodiesterases (10-fold for PDE6, >80-fold for PDE1, >700-fold for PDE2, PDE3, PDE4, PDE7, PDE8, PDE9, PDE10, and PDE11). Sildenafil is approximately 4,000-fold more selective for PDE5 compared to PDE3. PDE3 is involved in control of cardiac contractility. Sildenafil is only about 10-fold as potent for PDE5 compared to PDE6, an enzyme found in the retina which is involved in the phototransduction pathway of the retina. This lower selectivity is thought to be the basis for abnormalities related to color vision [ see Clinical Pharmacology (12.2)].In addition to human corpus cavernosum smooth muscle, PDE5 is also found in other tissues including platelets, vascular and visceral smooth muscle, and skeletal muscle, brain, heart, liver, kidney, lung, pancreas, prostate, bladder, testis, and seminal vesicle. The inhibition of PDE5 in some of these tissues by sildenafil may be the basis for the enhanced platelet antiaggregatory activity of NO observed in vitro, an inhibition of platelet thrombus formation in vivoand peripheral arterial-venous dilatation in vivo.12.2 PharmacodynamicsEffects of sildenafil on Erectile Response:In eight double-blind, placebo-controlled crossover studies of patients with either organic or psychogenic erectile dysfunction, sexual stimulation resulted in improved erections, as assessed by an objective measurement of hardness and duration of erections (RigiScan ®), after sildenafil administration compared with placebo.

Most studies assessed the efficacy of sildenafil approximately 60 minutes sildenafil 50mg tablet post dose.

5.6 Adverse Reactions with the Concomitant Use of Ritonavir

Following at least 14 consecutive daily doses of doxazosin, sildenafil 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 sildenafil dose was reduced to 25 mg. Thereafter, 17 subjects were treated with sildenafil 25 mg or matching placebo in combination with doxazosin 4 mg (15 subjects) or doxazosin 8 mg (2 subjects). The mean subject age was 66.5 years.For the 17 subjects who received sildenafil 25 mg and matching placebo, the placebo-subtracted mean maximum decreases from baseline (95% CI) in systolic blood pressure were as follows:The mean profiles of the change from baseline in standing systolic blood pressure in subjects treated with doxazosin in combination with 25 mg sildenafil or matching placebo are shown in Figure 2.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 sildenafil or matching placebo. Outliers were defined as subjects with a standing systolic blood pressure of <85 mmHg or a decrease from baseline in standing systolic blood pressure of >30 mmHg at one or more timepoints.

Comparison table

There were no subjects treated with sildenafil 25 mg who had a standing SBP < 85mmHg. There were three subjects with a decrease from baseline in standing systolic BP >30mmHg following sildenafil 25 mg, one subject with a decrease from baseline in sildenafil oral jelly 100mg standing systolic BP > 30 mmHg following placebo and two subjects with a decrease from baseline in standing systolic BP > 30 mmHg following both sildenafil and placebo. No severe adverse events potentially related to blood pressure effects were reported in this group.Of the four subjects who received sildenafil 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 sildenafil 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 < 85mmHg. The erectile response, as assessed by RigiScan ®, generally increased with increasing sildenafil dose and plasma concentration.

7.2 Alpha-blockers

This lower selectivity is thought to be the basis for abnormalities related to color vision [ see Clinical Pharmacology (12.2)].In addition to human corpus cavernosum smooth muscle, PDE5 is also found in other tissues including platelets, vascular and visceral smooth muscle, and skeletal muscle, brain, heart, liver, kidney, lung, pancreas, prostate, bladder, testis, and seminal vesicle. The inhibition of PDE5 in some of these tissues by sildenafil may be the basis for the enhanced platelet antiaggregatory activity of NO observed in vitro, an inhibition of platelet thrombus formation in vivoand peripheral arterial-venous dilatation in vivo.12.2 PharmacodynamicsEffects of sildenafil on Erectile Response:In eight double-blind, placebo-controlled crossover studies of patients with either organic or psychogenic erectile dysfunction, sexual stimulation resulted in improved erections, as assessed by an objective measurement of hardness and duration of erections (RigiScan ®), after sildenafil administration compared with placebo. Most studies assessed the efficacy of sildenafil approximately 60 minutes sildenafil 50mg tablet post dose. The erectile response, as assessed by RigiScan ®, generally increased with increasing sildenafil dose and plasma concentration. The time course of effect was examined in one study, showing an effect for up to 4 hours but the response was diminished compared to 2 hours.Effects of sildenafil on Blood Pressure:Single oral doses of sildenafil (100 mg) administered to healthy volunteers produced decreases in sitting blood pressure (mean maximum decrease in systolic/diastolic blood pressure of 8.3/5.3 mmHg).

Does Viagra prevent ejaculation?

The decrease in sitting blood pressure was most notable approximately 1-2 hours after dosing, and was not different than placebo at 8 hours. Similar effects on blood pressure were noted with 25 mg, 50 mg and 100 mg of sildenafil, therefore the effects are not related to dose or plasma levels within this dosage range. Larger effects were recorded among patients receiving concomitant nitrates [ see Contraindications (4.1)].Effects of sildenafil on Blood Pressure When Nitroglycerin is Subsequently Administered: Based on the pharmacokinetic profile of a single 100 mg oral dose given to healthy normal volunteers, the plasma levels of sildenafil at 24 hours post dose are approximately 2 ng/mL (compared to peak plasma levels of approximately 440 ng/mL). In the following patients: age >65 years, hepatic impairment (e.g., cirrhosis), severe renal impairment (e.g., creatinine clearance <30 mL/min), and concomitant use of erythromycin or strong CYP3A4 inhibitors, plasma levels of sildenafil at 24 hours post dose have been found to be 3 to 8 times higher than those seen in healthy volunteers. Although plasma levels of sildenafil at 24 hours post dose are much lower than at peak concentration, it is unknown whether nitrates can be safely co-administered at this time point [ see Contraindications (4.1)].Effects of sildenafil on Blood Pressure When Co-administered with Alpha-Blockers:Three double-blind, placebo-controlled, randomized, two-way crossover studies were conducted to assess the interaction of sildenafil with doxazosin, an alpha-adrenergic blocking agent.Study 1: Sildenafil with DoxazosinIn the first study, a single oral dose of sildenafil 100 mg or matching placebo was administered in a 2-period crossover design to 4 generally healthy males with benign prostatic hyperplasia (BPH). The time course of effect was examined in one study, showing an effect for up to 4 hours but the response was diminished compared to 2 hours.Effects of sildenafil on Blood Pressure:Single oral doses of sildenafil (100 mg) administered to healthy volunteers produced decreases in sitting blood pressure (mean maximum decrease in systolic/diastolic blood pressure of 8.3/5.3 mmHg). The decrease in sitting blood pressure was most notable approximately 1-2 hours after dosing, and was not different than placebo at 8 hours.

What is sildenafil?

Similar effects on blood pressure were noted with 25 mg, 50 mg and 100 mg of sildenafil, therefore the effects are not related to dose or plasma levels within this dosage range. Larger effects were recorded among patients receiving concomitant nitrates [ see Contraindications (4.1)].Effects of sildenafil on Blood Pressure When Nitroglycerin is Subsequently Administered: Based on the pharmacokinetic profile of a single 100 mg oral dose given to healthy normal volunteers, the plasma levels of sildenafil at 24 hours post dose are approximately 2 ng/mL (compared to peak plasma levels of approximately 440 ng/mL).

• Sildenafil citrate 100mg tablets are used globally for erectile treatment.
• The medication’s onset of action is typically within 30-60 minutes.
• Patients should avoid heavy or greasy foods before taking sildenafil.
• Do not consume alcohol as it can impair the effectiveness.
• Sildenafil does not cure erectile dysfunction but helps manage symptoms.
• Always take medication exactly as your doctor directs.
• Side effects can include dizziness, flushing, and nasal congestion.
• Check with your doctor if you are on other medications for safety.
• The medication is not suitable for patients with eye conditions like retinitis pigmentosa.
• Use sildenafil responsibly to prevent misuse or adverse health effects.
• Be aware of and report any persistent pain or changes in vision.
• Keep all medical appointments to monitor treatment progress.

In the following patients: age >65 years, hepatic impairment (e.g., cirrhosis), severe renal impairment (e.g., creatinine clearance <30 mL/min), and concomitant use of erythromycin or strong CYP3A4 inhibitors, plasma levels of sildenafil at 24 hours post dose have been found to be 3 to 8 times higher than those seen in healthy volunteers. Although plasma levels of sildenafil at 24 hours post dose are much lower than at peak concentration, it is unknown whether nitrates can be safely co-administered at this time point [ see Contraindications (4.1)].Effects of sildenafil on Blood Pressure When Co-administered with Alpha-Blockers:Three double-blind, placebo-controlled, randomized, two-way crossover studies were conducted to assess the interaction of sildenafil with doxazosin, an alpha-adrenergic blocking agent.Study 1: Sildenafil with DoxazosinIn the first study, a single oral dose of sildenafil 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, sildenafil 100 mg or matching placebo was administered simultaneously with doxazosin.

• Sildenafil citrate 100mg tablets are a popular choice for ED treatment.
• The medication helps achieve and maintain an erection suitable for intercourse.
• Use can be affected by other health conditions; always disclose complete medical history.
• Sildenafil has specific storage instructions to maintain effectiveness.
• The medication should be taken approximately one hour before needed.
• Patients should avoid combining sildenafil with certain antihypertensives.
• Expect some common side effects like headache and warmth.
• Report any serious side effects such as chest pain or sudden vision loss.
• Do not take sildenafil if you have low blood pressure or are on blood thinners.
• It is essential to follow your healthcare provider’s dosing guidelines.
• Do not use sildenafil if you are currently on nitrates for chest pain.
• Ensure understanding of all precautions before starting treatment.

Following a review of the data from these first 4 subjects (details provided below), the sildenafil dose was reduced to 25 mg. Thereafter, 17 subjects were treated with sildenafil 25 mg or matching placebo in combination with doxazosin 4 mg (15 subjects) or doxazosin 8 mg (2 subjects). The mean subject age was 66.5 years.For the 17 subjects who received sildenafil 25 mg and matching placebo, the placebo-subtracted mean maximum decreases from baseline (95% CI) in systolic blood pressure were as follows:The mean profiles of the change from baseline in standing systolic blood pressure in subjects treated with doxazosin in combination with 25 mg sildenafil or matching placebo are shown in Figure 2.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 sildenafil or matching placebo. Outliers were defined as subjects with a standing systolic blood pressure of <85 mmHg or a decrease from baseline in standing systolic blood pressure of >30 mmHg at one or more timepoints. There were no subjects treated with sildenafil 25 mg who had a standing SBP < 85mmHg. There were three subjects with a decrease from baseline in standing systolic BP >30mmHg following sildenafil 25 mg, one subject with a decrease from baseline in sildenafil oral jelly 100mg standing systolic BP > 30 mmHg following placebo and two subjects with a decrease from baseline in standing systolic BP > 30 mmHg following both sildenafil and placebo. No severe adverse events potentially related to blood pressure effects were reported in this group.Of the four subjects who received sildenafil 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 sildenafil 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 < 85mmHg.

Both of these subjects were protocol violators, one due to a low baseline standing SBP, and the other due to baseline orthostatic hypotension.Study 2: Sildenafil with DoxazosinIn the second study, a single oral dose of sildenafil 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, sildenafil 50 mg 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.Twenty subjects received sildenafil 50 mg, but only 19 subjects received matching placebo.

• Sildenafil citrate 100mg tablets are used to treat erectile dysfunction in men.
• The usual recommended dose is 100mg taken about an hour before activity.
• Sildenafil works by increasing blood flow to the penis during arousal.
• This medication should not be used with nitrate drugs due to risk of dangerous interactions.
• Common side effects include headache, flushing, upset stomach, and nasal congestion.
• Do not take sildenafil more than once in a 24-hour period.
• Sildenafil can cause hypotension, especially when combined with certain medications.
• It is available by prescription and should be used under medical supervision.
• Patients with heart problems should consult their doctor before use.
• Sildenafil should be stored at room temperature, away from moisture and heat.
• Alcohol can increase the risk of side effects when taking sildenafil.
• Sildenafil may cause vision changes such as blue tinge or increased sensitivity to light.

One patient discontinued the study prematurely due to an adverse event of hypotension following dosing with sildenafil 50 mg.

Usual Geriatric Dose for Erectile Dysfunction

Viagra and herbs and supplements

This patient had been taking minoxidil, a potent vasodilator, during the study.For the 19 subjects who received both sildenafil and matching placebo, the placebo-subtracted mean maximum decreases from baseline (95% CI) in systolic blood pressure were as follows:The mean profiles of the change from baseline in standing systolic blood pressure in subjects treated with doxazosin in combination with 50 mg sildenafil or matching placebo are shown in Figure 3.Blood pressure was measured after administration of sildenafil at the same times as those specified for the first doxazosin study. There were two subjects who had a standing SBP of < 85 mmHg. In these two subjects, hypotension was reported as a moderately severe adverse event, beginning at approximately 1 hour after administration of sildenafil 50 mg and resolving after approximately 7.5 hours. There was one subject with a decrease from baseline in standing systolic BP >30mmHg following sildenafil 50 mg and one subject with a decrease from baseline in standing systolic BP > 30 mmHg following both sildenafil 50 mg and placebo. There were no severe adverse events potentially related to blood pressure and no episodes of syncope reported in this study.Study 3: Sildenafil with DoxazosinIn the third study, a single oral dose of sildenafil 100 mg or matching placebo was administered in a 3-period crossover design to 20 generally healthy males with BPH.

7.3 Amlodipine

Both of these subjects were protocol violators, one due to a low baseline standing SBP, and the other due to baseline orthostatic hypotension.Study 2: Sildenafil with DoxazosinIn the second study, a single oral dose of sildenafil 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, sildenafil 50 mg 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.Twenty subjects received sildenafil 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 sildenafil 50 mg. This patient had been taking minoxidil, a potent vasodilator, during the study.For the 19 subjects who received both sildenafil and matching placebo, the placebo-subtracted mean maximum decreases from baseline (95% CI) in systolic blood pressure were as follows:The mean profiles of the change from baseline in standing systolic blood pressure in subjects treated with doxazosin in combination with 50 mg sildenafil or matching placebo are shown in Figure 3.Blood pressure was measured after administration of sildenafil at the same times as those specified for the first doxazosin study.

Does sildenafil interact with foods or drinks?

There were two subjects who had a standing SBP of < 85 mmHg. In these two subjects, hypotension was reported as a moderately severe adverse event, beginning at approximately 1 hour after administration of sildenafil 50 mg and resolving after approximately 7.5 hours. There was one subject with a decrease from baseline in standing systolic BP >30mmHg following sildenafil 50 mg and one subject with a decrease from baseline in standing systolic BP > 30 mmHg following both sildenafil 50 mg and placebo. There were no severe adverse events potentially related to blood pressure and no episodes of syncope reported in this study.Study 3: Sildenafil with DoxazosinIn the third study, a single oral dose of sildenafil 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 sildenafil 50 mg simultaneously, after at least 14 consecutive days of doxazosin. In dose period 1, subjects were administered open-label doxazosin and a single dose of sildenafil 50 mg simultaneously, after at least 14 consecutive days of doxazosin.

Frequently asked questions

Sildenafil citrate, USP is a white to off-white crystalline powder with a solubility of 3.5 mg/mL in water and a molecular weight of 666.7. Sildenafil tablets USP are formulated as pale blue to blue film-coated tablets equivalent to 25 mg, 50 mg and 100 mg of sildenafil for oral administration. 12 CLINICAL PHARMACOLOGY 12.1 Mechanism of ActionThe physiologic mechanism of erection of the penis involves release of nitric oxide (NO) in the corpus cavernosum during sexual stimulation. NO then activates the enzyme guanylate cyclase, which results in increased levels of cyclic guanosine monophosphate (cGMP), producing smooth muscle relaxation in the corpus cavernosum and allowing inflow of blood.Sildenafil enhances the effect of NO by inhibiting phosphodiesterase type 5 (PDE5), which is responsible for degradation of cGMP in the corpus cavernosum. When sexual stimulation causes local release of NO, inhibition of PDE5 by sildenafil causes increased levels of cGMP in the corpus cavernosum, resulting in smooth muscle relaxation and inflow of blood to the corpus cavernosum.

Incidence not known

Sildenafil at recommended doses has no effect in the absence of sexual stimulation.Binding CharacteristicsStudies in vitrohave shown that sildenafil is selective for PDE5. Its effect is more potent on PDE5 than on other known phosphodiesterases (10-fold for PDE6, >80-fold for PDE1, >700-fold for PDE2, PDE3, PDE4, PDE7, PDE8, PDE9, PDE10, and PDE11). Sildenafil is approximately 4,000-fold more selective for PDE5 compared to PDE3. PDE3 is involved in control of cardiac contractility. Sildenafil is only about 10-fold as potent for PDE5 compared to PDE6, an enzyme found in the retina which is involved in the phototransduction pathway of the retina.