I took 2 tablets of 20mg each sildenafil citrate andbarely had an effect. 3 hrs ago. Few years ago i took viagra 100 and
In some patients, concomitant use of these two drug classes can lower blood pressure significantly [ see Drug Interactions (7.2) and Clinical Pharmacology (12.2)] leading to symptomatic hypotension (e.g., dizziness, lightheadedness, fainting). Consideration should be given to the following: Patients who demonstrate hemodynamic instability on alpha-blocker therapy alone are at increased risk of symptomatic hypotension with concomitant use of PDE5 inhibitors. Patients should be stable on alpha-blocker therapy prior to initiating a PDE5 inhibitor. In those patients who are stable on alpha-blocker therapy, PDE5 inhibitors should be initiated at the lowest dose [ see Dosage and Administration (2.3)]. In those patients already taking an optimized dose of a PDE5 inhibitor, alpha-blocker therapy should be initiated at the lowest dose. Stepwise increase in alpha-blocker dose may be associated with further lowering of blood pressure when taking a PDE5 inhibitor.
Warnings & Precautions
In some patients, concomitant use of these two drug classes can lower blood pressure significantly [ see Drug Interactions (7.2) and Clinical Pharmacology (12.2)] leading to symptomatic hypotension (e.g., dizziness, lightheadedness, fainting). Consideration should be given to the following: Patients who demonstrate hemodynamic instability on alpha-blocker therapy alone are at increased risk of symptomatic hypotension with concomitant use of PDE5 inhibitors. Patients should be stable on alpha-blocker therapy prior to initiating a PDE5 inhibitor. In those patients who are stable on alpha-blocker therapy, PDE5 inhibitors should be initiated at the lowest dose [ see Dosage and Administration (2.3)]. In those patients already taking an optimized dose of a PDE5 inhibitor, alpha-blocker therapy should be initiated at the lowest dose.
Some side effects can be serious. If you experience any of the following symptoms, call your doctor immediately:
Stepwise increase in alpha-blocker dose may be associated with further lowering of blood pressure when taking a PDE5 inhibitor. Safety of combined use of PDE5 inhibitors and alpha-blockers may be affected by other variables, including intravascular volume depletion and other anti-hypertensive drugs. Sildenafil citrate has systemic vasodilatory properties and may further sildenafil 5mg for sale lower blood pressure in patients taking anti-hypertensive medications. In a separate drug interaction study, when amlodipine, 5 mg or 10 mg, and sildenafil citrate, 100 mg were orally administered concomitantly to hypertensive patients mean additional blood pressure reduction of 8 mmHg systolic and 7 mmHg diastolic were noted [ see Drug Interactions (7.3) and Clinical Pharmacology (12.2)]. To decrease the chance of adverse reactions in patients taking ritonavir, a decrease in sildenafil dosage is recommended [ see Dosage and Administration (2.4), Drug Interactions (7.4), and Clinical Pharmacology (12.3)].
How sildenafil is used
The safety and efficacy of combinations of sildenafil tablets, 25 mg, 50 mg and 100 mg with other PDE5 Inhibitors, including sildenafil tablets, 20 mg or other pulmonary arterial hypertension (PAH) treatments containing sildenafil, or other treatments for erectile dysfunction have not been studied. Therefore, the use of such combinations is not recommended. There have been postmarketing reports of bleeding events in patients who have taken sildenafil citrate. In addition, the combination of heparin and sildenafil citrate had an additive effect on bleeding time in the anesthetized rabbit, but this interaction has not been studied in humans. The safety of sildenafil citrate is unknown in patients with bleeding disorders and patients with active peptic ulceration. Safety of combined use of PDE5 inhibitors and alpha-blockers may be affected by other variables, including intravascular volume depletion and other anti-hypertensive drugs.
| Parameter | Value | Notes |
|---|---|---|
| Absorption Time | 30-120 minutes | Peak plasma levels in approx. 1 hour |
| Bioavailability | About 40% | Due to first-pass metabolism |
| T1/2 (Half-life) | 4-5 hours | Eliminated mainly via hepatic metabolism |
| Onset of Action | 30-60 minutes | Varies with food intake |
| Duration of Effect | Up to 4-6 hours | Depending on dose and individual |
Sildenafil citrate has systemic vasodilatory properties and may further sildenafil 5mg for sale lower blood pressure in patients taking anti-hypertensive medications.
| Product | Dosage | Quantity + Bonus | Price | |
|---|---|---|---|---|
| Viagra Generic | 200mg | 90 + 6 Pills | 170.79€ 162.66€ | |
| Viagra Generic | 100mg | 120 + 6 Pills | 149.50€ 142.38€ | |
| Kamagra | 100mg | 360 + 6 Pills | 839.95€ 799.95€ | |
| Viagra Generic | 150mg | 30 + 2 Pills | 72.32€ 68.88€ | |
| Viagra Generic | 200mg | 360 + 10 Pills | 481.98€ 459.03€ | |
| Kamagra Oral Jelly | 100mg | 90 + 8 Sachets | 303.56€ 289.10€ | |
| Viagra Generic | 100mg | 20 Pills | 45.58€ 43.41€ | |
| Viagra Generic | 150mg | 120 + 8 Pills | 177.58€ 169.12€ | |
| Viagra Generic | 25mg | 30 + 4 Pills | 47.97€ 45.69€ | |
| Kamagra Soft Tabs | 100mg | 180 + 8 Pills | 425.45€ 405.19€ | |
| Viagra Generic | 200mg | 180 + 10 Pills | 277.56€ 264.34€ | |
| Viagra Generic | 25mg | 120 + 6 Pills | 125.56€ 119.58€ | |
| Kamagra Soft Tabs | 100mg | 32 Pills | 120.11€ 114.39€ | |
| Kamagra Oral Jelly | 100mg | 220 + 18 Sachets | 662.24€ 630.70€ | |
| Viagra Generic | 50mg | 270 + 8 Pills | 198.48€ 189.03€ | |
| Viagra Generic | 150mg | 360 + 10 Pills | 423.48€ 403.31€ | |
| Viagra Generic | 150mg | 90 + 6 Pills | 147.18€ 140.17€ |
In a separate drug interaction study, when amlodipine, 5 mg or 10 mg, and sildenafil citrate, 100 mg were orally administered concomitantly to hypertensive patients mean additional blood pressure reduction of 8 mmHg systolic and 7 mmHg diastolic were noted [ see Drug Interactions (7.3) and Clinical Pharmacology (12.2)]. To decrease the chance of adverse reactions in patients taking ritonavir, a decrease in sildenafil dosage is recommended [ see Dosage and Administration (2.4), Drug Interactions (7.4), and Clinical Pharmacology (12.3)]. The safety and efficacy of combinations of sildenafil tablets, 25 mg, 50 mg and 100 mg with other PDE5 Inhibitors, including sildenafil tablets, 20 mg or other pulmonary arterial hypertension (PAH) treatments containing sildenafil, or other treatments for erectile dysfunction have not been studied. Therefore, the use of such combinations is not recommended.
5.8 Vaso-occlusive Crisis in Patients with Pulmonary Hypertension Secondary to Sickle Cell Disease
The use of sildenafil citrate offers no protection against sexually transmitted diseases. 6 ADVERSE REACTIONS The following are discussed in more detail in other sections of the labeling:Cardiovascular [ see Warnings and Precautions (5.1)]Prolonged Erection and Priapism [ see Warnings and Precautions (5.2)]Effects on the Eye [ see Warnings and Precautions (5.3)]Hearing Loss [ see Warnings and Precautions (5.4)]Hypotension when Co-administered with Alpha-blockers or Anti-hypertensives [ see Warnings and Precautions (5.5)]Adverse Reactions with the Concomitant Use of Ritonavir [ see Warnings and Precautions (5.6)]Combination with other PDE5 Inhibitors or Other Erectile Dysfunction Therapies [ see Warnings and Precautions (5.7)]Effects on Bleeding [ see Warnings and Precautions (5.8)]Counseling Patients About Sexually Transmitted Diseases [ see Warnings and Precautions (5.9)]The most common adverse reactions reported in clinical trials (≥ 2%) are headache, flushing, dyspepsia, abnormal vision, nasal congestion, back pain, myalgia, nausea, dizziness, and rash.6.1 Clinical Trials ExperienceBecause clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice.Sildenafil citrate was administered to over 3,700 patients (aged 19 to 87 years) during pre-marketing clinical trials worldwide. Over 550 patients were treated for longer than one year.In placebo-controlled clinical studies, the discontinuation rate due to adverse reactions for sildenafil citrate (2.5%) was not significantly different from placebo (2.3%).In fixed-dose studies, the incidence of some adverse reactions increased with dose. The type of adverse reactions in flexible-dose studies, which reflect the recommended dosage regimen, was sildenafil 100mg hexal similar to that for fixed-dose studies. At doses above the recommended dose range, adverse reactions were similar to those detailed in Table 1 below but generally were reported more frequently.†Abnormal Vision: Mild to moderate in severity and transient, predominantly color tinge to vision, but also increased sensitivity to light, or blurred vision.When sildenafil citrate was taken as recommended (on an as-needed basis) in flexible-dose, placebo-controlled clinical trials of two to twenty-six weeks duration, patients took sildenafil citrate at least once weekly, and the following adverse reactions were reported:†Abnormal Vision: Mild and transient, predominantly color tinge to vision, but also increased sensitivity to light, or blurred vision.
Elderly Precautions
In these studies, only one patient discontinued due to abnormal vision.The following events occurred in <2% of patients in controlled clinical trials; a causal relationship to sildenafil citrate is uncertain. This analysis was performed retrospectively, and was not powered to detect any pre-specified difference in adverse reactions.6.2 Postmarketing ExperienceThe following adverse reactions have been identified during post approval use of sildenafil citrate. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. These events have been chosen for inclusion either due to their seriousness, reporting frequency, lack of clear alternative causation, or a combination of these factors.Cardiovascular and cerebrovascularSerious cardiovascular, cerebrovascular, and vascular events, including myocardial infarction, sudden cardiac death, ventricular arrhythmia, cerebrovascular hemorrhage, transient ischemic attack, hypertension, subarachnoid and intracerebral hemorrhages, and pulmonary hemorrhage have been reported post-marketing in temporal association with the use of sildenafil citrate. Most, but not all, of these patients had preexisting cardiovascular risk factors.
Altitude sickness
Many of these events were reported to occur during or shortly after sexual activity, and a few were reported to occur shortly after the use of sildenafil citrate without sexual activity. Others were reported to have occurred hours to days after the use of sildenafil citrate and sexual activity. It is not possible to determine whether these events are related directly to sildenafil citrate, to sexual activity, to the patient’s underlying cardiovascular disease, to a combination of these factors, or to other factors [ see Warnings and Precautions (5.1) and Patient Counseling Information (17)].Hemic and Lymphatic: vaso-occlusive crisis: In a small, prematurely terminated study of sildenafil tablets, 20 mg (sildenafil) in patients with pulmonary arterial hypertension (PAH) secondary to sickle cell disease, vaso-occlusive crises requiring hospitalization were more commonly reported in patients who received sildenafil than in those randomized to placebo. The clinical relevance of sildenafil 10mg this finding to men treated with sildenafil tablets, 25 mg, 50 mg and 100 mg for ED is not known.Nervous: seizure, seizure recurrence, anxiety, and transient global amnesia.Respiratory: epistaxisSpecial senses:Hearing: Cases of sudden decrease or loss of hearing have been reported postmarketing in temporal association with the use of PDE5 inhibitors, including sildenafil citrate. In some of the cases, medical conditions and other factors were reported that may have also played a role in the otologic adverse events. There have been postmarketing reports of bleeding events in patients who have taken sildenafil citrate.
- Typical sildenafil dose ranges from 25 to 100 mg.
- It should be taken 30-60 minutes before activity.
- Do not exceed one dose within 24 hours.
In addition, the combination of heparin and sildenafil citrate had an additive effect on bleeding time in the anesthetized rabbit, but this interaction has not been studied in humans.
What happens if I miss a dose?
The safety of sildenafil citrate is unknown in patients with bleeding disorders and patients with active peptic ulceration. The use of sildenafil citrate offers no protection against sexually transmitted diseases. 6 ADVERSE REACTIONS The following are discussed in more detail in other sections of the labeling:Cardiovascular [ see Warnings and Precautions (5.1)]Prolonged Erection and Priapism [ see Warnings and Precautions (5.2)]Effects on the Eye [ see Warnings and Precautions (5.3)]Hearing Loss [ see Warnings and Precautions (5.4)]Hypotension when Co-administered with Alpha-blockers or Anti-hypertensives [ see Warnings and Precautions (5.5)]Adverse Reactions with the Concomitant Use of Ritonavir [ see Warnings and Precautions (5.6)]Combination with other PDE5 Inhibitors or Other Erectile Dysfunction Therapies [ see Warnings and Precautions (5.7)]Effects on Bleeding [ see Warnings and Precautions (5.8)]Counseling Patients About Sexually Transmitted Diseases [ see Warnings and Precautions (5.9)]The most common adverse reactions reported in clinical trials (≥ 2%) are headache, flushing, dyspepsia, abnormal vision, nasal congestion, back pain, myalgia, nausea, dizziness, and rash.6.1 Clinical Trials ExperienceBecause clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice.Sildenafil citrate was administered to over 3,700 patients (aged 19 to 87 years) during pre-marketing clinical trials worldwide. Over 550 patients were treated for longer than one year.In placebo-controlled clinical studies, the discontinuation rate due to adverse reactions for sildenafil citrate (2.5%) was not significantly different from placebo (2.3%).In fixed-dose studies, the incidence of some adverse reactions increased with dose. The type of adverse reactions in flexible-dose studies, which reflect the recommended dosage regimen, was sildenafil 100mg hexal similar to that for fixed-dose studies. At doses above the recommended dose range, adverse reactions were similar to those detailed in Table 1 below but generally were reported more frequently.†Abnormal Vision: Mild to moderate in severity and transient, predominantly color tinge to vision, but also increased sensitivity to light, or blurred vision.When sildenafil citrate was taken as recommended (on an as-needed basis) in flexible-dose, placebo-controlled clinical trials of two to twenty-six weeks duration, patients took sildenafil citrate at least once weekly, and the following adverse reactions were reported:†Abnormal Vision: Mild and transient, predominantly color tinge to vision, but also increased sensitivity to light, or blurred vision.
- Sildenafil citrate was originally developed for hypertension.
- It was later approved for erectile dysfunction treatment.
- Brand names include Viagra and Revatio.
In these studies, only one patient discontinued due to abnormal vision.The following events occurred in <2% of patients in controlled clinical trials; a causal relationship to sildenafil citrate is uncertain. This analysis was performed retrospectively, and was not powered to detect any pre-specified difference in adverse reactions.6.2 Postmarketing ExperienceThe following adverse reactions have been identified during post approval use of sildenafil citrate. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. These events have been chosen for inclusion either due to their seriousness, reporting frequency, lack of clear alternative causation, or a combination of these factors.Cardiovascular and cerebrovascularSerious cardiovascular, cerebrovascular, and vascular events, including myocardial infarction, sudden cardiac death, ventricular arrhythmia, cerebrovascular hemorrhage, transient ischemic attack, hypertension, subarachnoid and intracerebral hemorrhages, and pulmonary hemorrhage have been reported post-marketing in temporal association with the use of sildenafil citrate. Most, but not all, of these patients had preexisting cardiovascular risk factors. Many of these events were reported to occur during or shortly after sexual activity, and a few were reported to occur shortly after the use of sildenafil citrate without sexual activity. Others were reported to have occurred hours to days after the use of sildenafil citrate and sexual activity. It is not possible to determine whether these events are related directly to sildenafil citrate, to sexual activity, to the patient’s underlying cardiovascular disease, to a combination of these factors, or to other factors [ see Warnings and Precautions (5.1) and Patient Counseling Information (17)].Hemic and Lymphatic: vaso-occlusive crisis: In a small, prematurely terminated study of sildenafil tablets, 20 mg (sildenafil) in patients with pulmonary arterial hypertension (PAH) secondary to sickle cell disease, vaso-occlusive crises requiring hospitalization were more commonly reported in patients who received sildenafil than in those randomized to placebo. The clinical relevance of sildenafil 10mg this finding to men treated with sildenafil tablets, 25 mg, 50 mg and 100 mg for ED is not known.Nervous: seizure, seizure recurrence, anxiety, and transient global amnesia.Respiratory: epistaxisSpecial senses:Hearing: Cases of sudden decrease or loss of hearing have been reported postmarketing in temporal association with the use of PDE5 inhibitors, including sildenafil citrate.
| Property | Description | Value | Notes |
|---|---|---|---|
| Molecular Formula | C22H30N6O4S | ||
| Molecular Weight | 474.58 g/mol | ||
| Melting Point | 189-192°C | ||
| Solubility in Water | Slightly soluble | at 25°C | |
| pH Range | 3.8 - 4.0 | in aqueous solution |
In some of the cases, medical conditions and other factors were reported that may have also played a role in the otologic adverse events. In many cases, medical follow-up information was limited. It is not possible to determine whether these reported events are related directly to the use of sildenafil citrate, to the patient’s underlying risk factors for hearing loss, a combination of these factors, or to other factors [ see Warnings and Precautions (5.4) and Patient Counseling Information (17)].Ocular: diplopia, temporary vision loss/decreased vision, ocular redness or bloodshot appearance, ocular burning, ocular swelling/pressure, increased intraocular pressure, retinal edema, retinal vascular disease or bleeding, and vitreous traction/detachment.Non-arteritic anterior ischemic optic neuropathy (NAION), a cause of decreased vision including permanent loss of vision, has been reported rarely post-marketing in temporal association with the use of phosphodiesterase type 5 (PDE5) inhibitors, including sildenafil citrate.
Other Comments
In many cases, medical follow-up information was limited. It is not possible to determine whether these reported events are related directly to the use of sildenafil citrate, to the patient’s underlying risk factors for hearing loss, a combination of these factors, or to other factors [ see Warnings and Precautions (5.4) and Patient Counseling Information (17)].Ocular: diplopia, temporary vision loss/decreased vision, ocular redness or bloodshot appearance, ocular burning, ocular swelling/pressure, increased intraocular pressure, retinal edema, retinal vascular disease or bleeding, and vitreous traction/detachment.Non-arteritic anterior ischemic optic neuropathy (NAION), a cause of decreased vision including permanent loss of vision, has been reported rarely post-marketing in temporal association with the use of phosphodiesterase type 5 (PDE5) inhibitors, including sildenafil citrate. Most, but not all, of these patients had underlying anatomic or vascular risk factors for developing NAION, including but not necessarily limited to: low cup to disc ratio (“crowded disc”), age over 50, diabetes, hypertension, coronary artery disease, hyperlipidemia and smoking [ see Warnings and Precautions (5.3) and Patient Counseling Information (17)].Urogenital: prolonged erection, priapism [ see Warnings and Precautions (5.2) and Patient Counseling Information (17)], and hematuria. The following are discussed in more detail in other sections of the labeling: Cardiovascular [ see Warnings and Precautions (5.1)] Prolonged Erection and Priapism [ see Warnings and Precautions (5.2)] Effects on the Eye [ see Warnings and Precautions (5.3)] Hearing Loss [ see Warnings and Precautions (5.4)] Hypotension when Co-administered with Alpha-blockers or Anti-hypertensives [ see Warnings and Precautions (5.5)] Adverse Reactions with the Concomitant Use of Ritonavir [ see Warnings and Precautions (5.6)] Combination with other PDE5 Inhibitors or Other Erectile Dysfunction Therapies [ see Warnings and Precautions (5.7)] Effects on Bleeding [ see Warnings and Precautions (5.8)] Counseling Patients About Sexually Transmitted Diseases [ see Warnings and Precautions (5.9)] The most common adverse reactions reported in clinical trials (≥ 2%) are headache, flushing, dyspepsia, abnormal vision, nasal congestion, back pain, myalgia, nausea, dizziness, and rash.
Clinical monitoring
What’s the difference between sildenafil and Viagra?
Most, but not all, of these patients had underlying anatomic or vascular risk factors for developing NAION, including but not necessarily limited to: low cup to disc ratio (“crowded disc”), age over 50, diabetes, hypertension, coronary artery disease, hyperlipidemia and smoking [ see Warnings and Precautions (5.3) and Patient Counseling Information (17)].Urogenital: prolonged erection, priapism [ see Warnings and Precautions (5.2) and Patient Counseling Information (17)], and hematuria.
| Medication Class | Interaction Type | Effect | Clinical Significance |
|---|---|---|---|
| Nitrates | Additive hypotensive effect | Severe hypotension | Contraindicated |
| Alpha-blockers | Enhanced hypotension | Blood pressure drop | Use with caution |
| CYP3A4 inhibitors | Increased sildenafil levels | Prolonged or intensified side effects | Dose adjustment may be needed |
| Protease inhibitors | Elevated sildenafil levels | Increased adverse effects | Monitoring required |
The following are discussed in more detail in other sections of the labeling: Cardiovascular [ see Warnings and Precautions (5.1)] Prolonged Erection and Priapism [ see Warnings and Precautions (5.2)] Effects on the Eye [ see Warnings and Precautions (5.3)] Hearing Loss [ see Warnings and Precautions (5.4)] Hypotension when Co-administered with Alpha-blockers or Anti-hypertensives [ see Warnings and Precautions (5.5)] Adverse Reactions with the Concomitant Use of Ritonavir [ see Warnings and Precautions (5.6)] Combination with other PDE5 Inhibitors or Other Erectile Dysfunction Therapies [ see Warnings and Precautions (5.7)] Effects on Bleeding [ see Warnings and Precautions (5.8)] Counseling Patients About Sexually Transmitted Diseases [ see Warnings and Precautions (5.9)] The most common adverse reactions reported in clinical trials (≥ 2%) are headache, flushing, dyspepsia, abnormal vision, nasal congestion, back pain, myalgia, nausea, dizziness, and rash.