4 CONTRAINDICATIONS
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.
- Regular monitoring may be necessary when using high doses of sildenafil citrate.
- Sildenafil citrate can cause side effects like low blood pressure and headache.
- Discontinue use and seek medical attention if adverse reactions are severe or persistent.
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 vivo and peripheral arterial-venous dilatation in vivo.12.2 PharmacodynamicsEffects of sildenafil tablets 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 tablets administration compared with placebo. Most studies assessed the efficacy of sildenafil tablets approximately 60 minutes post dose.
- 200mg sildenafil citrate is used in specific cases, often requiring specialist approval.
- Overdose symptoms include severe hypotension, vision loss, and persistent erections.
- Follow your healthcare provider’s instructions precisely when using high-dose sildenafil.
The erectile response, as assessed by RigiScan®, generally increased with increasing sildenafil dose and plasma concentration.
7.4 Ritonavir and other CYP3A4 Inhibitors
THERAPEUTIC INDICATIONS:
Serious Side Effects
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 tablets 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. Similar effects on blood pressure were noted with 25 mg, 50 mg and 100 mg of sildenafil tablets, 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 tablets 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 sildenafil online ireland 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 tablets 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 tablets with doxazosin, an alpha-adrenergic blocking agent.Study 1: Sildenafil tablets with DoxazosinIn the first study, a single oral dose of sildenafil tablets 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 tablets 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 citrate dose was reduced to 25 mg. Thereafter, 17 subjects were treated with sildenafil tablets 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 tablets 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 tablets or matching placebo are shown in Figure 2.Figure 2: Mean Standing Systolic Blood Pressure Change from BaselineBlood 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 tablets 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 tablets 25 mg who had a standing SBP < 85mmHg.
| Product | Dosage | Quantity + Bonus | Price | |
|---|---|---|---|---|
| Viagra Generic | 50mg | 20 Pills | 40.52€ 38.59€ | |
| Viagra Generic | 100mg | 20 Pills | 45.58€ 43.41€ | |
| Kamagra Oral Jelly | 100mg | 30 + 5 Sachets | 136.20€ 129.71€ | |
| Viagra Generic | 150mg | 180 + 10 Pills | 236.46€ 225.20€ | |
| Kamagra Polo | 100mg | 180 + 8 Pills | 446.52€ 425.26€ | |
| Viagra Generic | 25mg | 30 + 4 Pills | 47.97€ 45.69€ | |
| Viagra Generic | 25mg | 180 + 6 Pills | 154.93€ 147.55€ | |
| Kamagra | 100mg | 20 Pills | 86.09€ 81.99€ | |
| Viagra Generic | 150mg | 10 Pills | 36.73€ 34.98€ | |
| Viagra Generic | 100mg | 10 Pills | 28.91€ 27.53€ | |
| Kamagra Oral Jelly | 100mg | 220 + 18 Sachets | 662.24€ 630.70€ | |
| Kamagra Soft Tabs | 100mg | 180 + 8 Pills | 425.45€ 405.19€ | |
| Kamagra Oral Jelly | 100mg | 21 Sachets | 95.92€ 91.35€ | |
| Kamagra Soft Tabs | 100mg | 20 Pills | 79.79€ 75.99€ | |
| Kamagra Oral Jelly | 100mg | 10 Sachets | 54.55€ 51.95€ | |
| Kamagra | 100mg | 360 + 6 Pills | 839.95€ 799.95€ |
There were three subjects with a decrease from baseline in standing systolic BP >30mmHg following sildenafil tablets 25 mg, one subject with a decrease from baseline in standing systolic BP > 30 mmHg following placebo and two subjects with a decrease from baseline in standing systolic BP > 30 mmHg following both sildenafil tablets and placebo.
5.9 Counseling Patients About Sexually Transmitted Diseases
Following a review of the data from these first 4 subjects (details provided below), the sildenafil citrate dose was reduced to 25 mg. Thereafter, 17 subjects were treated with sildenafil tablets 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 tablets 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 tablets or matching placebo are shown in Figure 2.Figure 2: Mean Standing Systolic Blood Pressure Change from BaselineBlood 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 tablets 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 tablets 25 mg who had a standing SBP < 85mmHg.
Sildenafil Tablets or Oral Suspension for PAH
There were three subjects with a decrease from baseline in standing systolic BP >30mmHg following sildenafil tablets 25 mg, one subject with a decrease from baseline in standing systolic BP > 30 mmHg following placebo and two subjects with a decrease from baseline in standing systolic BP > 30 mmHg following both sildenafil tablets and placebo. No severe adverse events potentially related to blood pressure effects were reported in this group.Of the four subjects who received sildenafil tablets 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 tablets 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.
Related products
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 tablets with DoxazosinIn the second study, a single oral dose of sildenafil tablets 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 tablets 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 tablets 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 tablets sildenafil pink pill 50 mg. This patient had been taking minoxidil, a potent vasodilator, during the study.For the 19 subjects who received both sildenafil tablets 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 tablets or matching placebo are shown in Figure 3.Blood pressure was measured after administration of sildenafil tablets at the same times as those specified for the first doxazosin study. No severe adverse events potentially related to blood pressure effects were reported in this group.Of the four subjects who received sildenafil tablets 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 tablets 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.
Why Taj Pharma is the Most Trusted Manufacturer, Supplier & Exporter
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.
| Country | Approved Use | Prescription Required | Maximum Allowed Dose | Notes |
|---|---|---|---|---|
| United States | Erectile Dysfunction | Yes | 100mg tablet max | 200mg often not approved OTC |
| European Union | Erectile Dysfunction | Yes | 100mg per dose | 200mg used only under medical supervision |
| Australia | Pulmonary Hypertension | Yes | Up to 200mg daily | Under special prescription |
| India | Both Uses | Yes | 200mg dose | Commonly available in pharmacies |
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 tablets with DoxazosinIn the second study, a single oral dose of sildenafil tablets 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 tablets 50 mg or matching placebo was administered simultaneously with doxazosin 4 mg (17 subjects) or with doxazosin 8 mg (3 subjects).
- Sildenafil citrate 200mg may cause vision changes such as blue tinting.
- Do not take sildenafil citrate if prone to cardiovascular issues without doctor approval.
- Side effects can include dizziness, nasal congestion, and stomach upset.
The mean subject age in this study was 63.9 years.Twenty subjects received sildenafil tablets 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 tablets sildenafil pink pill 50 mg. This patient had been taking minoxidil, a potent vasodilator, during the study.For the 19 subjects who received both sildenafil tablets 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 tablets or matching placebo are shown in Figure 3.Blood pressure was measured after administration of sildenafil tablets at the same times as those specified for the first doxazosin study. There were two subjects who had a standing SBP of < 85 mmHg.
8.2 Lactation
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 tablets 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 tablets 50 mg and one subject with a decrease from baseline in standing systolic BP > 30 mmHg following both sildenafil tablets 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 tablets with DoxazosinIn the third study, a single oral dose of sildenafil tablets 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 tablets 50 mg simultaneously, after at least 14 consecutive days of doxazosin.
Sildenafil Tablets for ED
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 sildenafil tablets 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, sildenafil tablets 100 mg 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.Twenty-five subjects were screened.
Missed Dose
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 sildenafil tablets 50 mg. In these two subjects, hypotension was reported as a moderately severe adverse event, beginning at approximately 1 hour after administration of sildenafil tablets 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 tablets 50 mg and one subject with a decrease from baseline in standing systolic BP > 30 mmHg following both sildenafil tablets 50 mg and placebo.
| Use Case | Patient Group | Typical Dosage | Onset Time | Duration of Effect |
|---|---|---|---|---|
| Erectile Dysfunction | Men aged 18-65 | 200mg | 30-60 min | Up to 4-6 hours |
| Pulmonary Hypertension | Adults with PAH | 200mg titrated | 15-30 min | 4-6 hours |
| Off-label for Altitude Sickness | High-altitude climbers | 200mg | 1-2 hours | Varies |
There were no severe adverse events potentially related to blood pressure and no episodes of syncope reported in this study.Study 3: Sildenafil tablets with DoxazosinIn the third study, a single oral dose of sildenafil tablets 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 tablets 50 mg simultaneously, after at least 14 consecutive days of doxazosin. If a subject did not successfully complete this first dosing period, he was discontinued from the study.
Side Effects
Subjects who had successfully completed the previous doxazosin interaction study (using sildenafil tablets 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, sildenafil tablets 100 mg or matching placebo was administered simultaneously with doxazosin 4 mg (14 subjects) or doxazosin 8 mg (6 subjects) in standard crossover fashion.
- The onset of action for sildenafil citrate is typically 30 minutes, but varies among individuals.
- Sildenafil citrate can last 4-6 hours, depending on dosage and personal metabolism.
- Use sildenafil citrate responsibly to prevent dependence or misuse.
The mean subject age in this study was 66.4 years.Twenty-five subjects were screened.
12.3 Pharmacokinetics
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.
4. Export Certifications
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 vivo and peripheral arterial-venous dilatation in vivo.12.2 PharmacodynamicsEffects of sildenafil tablets 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 tablets administration compared with placebo. Most studies assessed the efficacy of sildenafil tablets approximately 60 minutes 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 tablets 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.
Want to leave a review?
Similar effects on blood pressure were noted with 25 mg, 50 mg and 100 mg of sildenafil tablets, 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 tablets 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 sildenafil online ireland 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 tablets 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 tablets with doxazosin, an alpha-adrenergic blocking agent.Study 1: Sildenafil tablets with DoxazosinIn the first study, a single oral dose of sildenafil tablets 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 tablets 100 mg or matching placebo was administered simultaneously with doxazosin. 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 sildenafil tablets 50 mg.
