ADVERSE REACTIONS
Population pharmacokinetic data from patients in clinical trials also
What is Sildenafil Citrate?
There were no episodes of syncope reported in this study. Effect of Sildenafil citrate on Blood Pressure When Co-administered with Anti-hypertensives:When sildenafil citrate 100 mg oral was co-administered with amlodipine, 5 mg or 10 mg oral, to hypertensive patients, the mean additional reduction on supine blood pressure was 8 mmHg systolic and 7 mmHg diastolic. Effect of Sildenafil citrate on Blood Pressure When Co-administered with Alcohol:Sildenafil citrate (50 mg) did not potentiate the hypotensive effect of alcohol (0.5 g/kg) in healthy volunteers with mean maximum blood alcohol levels of 0.08%. The maximum recommended dose of 100 mg sildenafil was not evaluated in this study [ see Drug Interactions (7.5)]. Effects of Sildenafil citrate on Cardiac Parameters:Single oral doses of sildenafil up to 100 mg produced no clinically relevant changes in the ECGs of normal male volunteers.
What Is the Maximum Safe Sildenafil Dosage?
Studies have produced relevant data on the effects of sildenafil citrate on cardiac output. A total dose of 40 mg sildenafil was administered by four intravenous infusions. The results from this pilot study are shown in Table 3; the mean resting systolic and diastolic blood pressures decreased by 7% and 10% compared to baseline in these patients. Even though this total dosage produced plasma sildenafil concentrations which were approximately 2 to 5 times higher than the mean maximum plasma concentrations following a single oral dose of 100 mg in healthy male volunteers, the hemodynamic response blue sildenafil to exercise was preserved in these patients. In a double-blind study, 144 patients with erectile dysfunction and chronic stable angina limited by exercise, not receiving chronic oral nitrates, were randomized to a single dose of placebo or sildenafil citrate 100 mg 1 hour prior to exercise testing.
Revatio Injection
These results demonstrated that the effect of sildenafil citrate on the primary endpoint was statistically non-inferior to placebo. Effects of Sildenafil citrate on Vision:At single oral doses of 100 mg and 200 mg, transient dose-related impairment of color discrimination was detected using the Farnsworth-Munsell 100-hue test, with peak effects near the time of peak plasma levels. An evaluation of visual function at doses up to twice the maximum recommended dose revealed no effects of sildenafil citrate on visual acuity, intraocular pressure, or pupillometry. Effects of Sildenafil citrate on Sperm:There was no effect on sperm motility or morphology after single 100 mg oral doses of sildenafil citrate in healthy volunteers. Sildenafil citrate is rapidly absorbed after oral administration, with a mean absolute bioavailability of 41% (range 25 to 63%). indicated a reduction in sildenafil clearance when it was
| Product | Dosage | Quantity + Bonus | Price | |
|---|---|---|---|---|
| Viagra Generic | 50mg | 10 Pills | 26.87€ 25.59€ | |
| Kamagra Oral Jelly | 100mg | 63 + 7 Sachets | 224.18€ 213.50€ | |
| Viagra Generic | 200mg | 180 + 10 Pills | 277.56€ 264.34€ | |
| Kamagra Soft Tabs | 100mg | 32 Pills | 120.11€ 114.39€ | |
| Kamagra | 100mg | 120 + 6 Pills | 330.74€ 314.99€ | |
| Kamagra | 100mg | 20 Pills | 86.09€ 81.99€ | |
| Viagra Generic | 150mg | 60 + 4 Pills | 111.25€ 105.95€ | |
| Kamagra | 100mg | 60 + 4 Pills | 201.34€ 191.75€ | |
| Viagra Generic | 50mg | 120 + 6 Pills | 129.64€ 123.47€ | |
| Viagra Generic | 150mg | 180 + 10 Pills | 236.46€ 225.20€ | |
| Viagra Generic | 100mg | 10 Pills | 28.91€ 27.53€ | |
| Kamagra Polo | 100mg | 32 Pills | 125.88€ 119.89€ | |
| Viagra Generic | 25mg | 60 + 4 Pills | 71.99€ 68.56€ | |
| Kamagra Polo | 100mg | 120 + 6 Pills | 327.15€ 311.57€ | |
| Viagra Generic | 25mg | 30 + 4 Pills | 47.97€ 45.69€ | |
| Kamagra Soft Tabs | 100mg | 60 + 4 Pills | 180.59€ 171.99€ |
co-administered with CYP3A4 inhibitors (such as ketoconazole, erythromycin, or
- Sildenafil citrate is primarily used to treat erectile dysfunction.
- 120 mg is a high dosing level and should only be used under medical supervision.
- The typical starting dose for sildenafil is 50 mg; 120 mg exceeds standard recommendations.
- High doses can increase the risk of side effects such as headaches and low blood pressure.
- Sildenafil works by relaxing blood vessels in the penis to facilitate an erection.
- Overdose of sildenafil citrate can cause severe hypotension and vision disturbances.
cimetidine) [ see Dosage and
- Sildenafil 120 mg can cause flushing and nasal congestion as common side effects.
- It is important to follow medical advice to minimize health risks.
- The drug's effectiveness can be influenced by other health conditions like diabetes.
- Consuming grapefruit or grapefruit juice may affect sildenafil’s metabolism.
- Patients should seek emergency care if experiencing an erection lasting longer than 4 hours.
- Sildenafil’s effects typically last about 4-6 hours, depending on individual factors.
Administration (2.4)and Drug Interactions (7.4)].
| Country | Approval Status | Maximum Allowed Dose | Remarks |
|---|---|---|---|
| United States | Approved for ED and pulmonary hypertension | 120 mg | Prescription-only, controlled use |
| European Union | Approved for ED, off-label for other uses | 120 mg | Stringent prescribing regulations |
| Canada | Approved, similar to US | 120 mg | Must be prescribed by healthcare provider |
| Australia | Approved with restrictions | 120 mg | Medical supervision required |
| India | Available, OTC in some regions | 120 mg | Use under medical guidance recommended |
In another study in healthy male
How Sildenafil Citrate Works in the Body
Both sildenafil and the metabolite have terminal half lives of about 4 hours. Mean sildenafil plasma concentrations measured after the administration of a single oral dose of 100 mg to healthy male volunteers is depicted below: Figure 5: Mean Sildenafil Plasma Concentrations in Healthy Male Volunteers. Absorption and Distribution:Sildenafil citrate is rapidly absorbed. Protein binding is independent of total drug concentrations. Based upon measurements of sildenafil in semen of healthy volunteers 90 minutes after dosing, less than 0.001% of the administered dose may appear in the semen of patients.
Pharmacokinetics in Special Populations
Metabolism and Excretion:Sildenafil is cleared predominantly by the CYP3A4 (major route) and CYP2C9 (minor route) hepatic microsomal isoenzymes. Plasma concentrations of this metabolite are approximately 40% of those seen for sildenafil, so that the metabolite accounts for about 20% of sildenafil’s pharmacologic effects. After either oral or intravenous administration, sildenafil is excreted as metabolites predominantly in the feces (approximately 80% of administered oral dose) and to a lesser extent in the urine (approximately 13% of the administered oral dose). Similar values for pharmacokinetic parameters were seen in normal volunteers and in the patient population, using a population pharmacokinetic approach. Geriatrics:Healthy elderly volunteers (65 years or over) had a reduced clearance of sildenafil, resulting in approximately 84% and 107% higher plasma AUC values of sildenafil and its active N-desmethyl metabolite, respectively, compared to those seen in healthy younger volunteers (18 to 45 years).
Why it’s used
Due to age-differences in plasma protein binding, the corresponding increase in the AUC of free (unbound) sildenafil and its active N-desmethyl metabolite were 45% and 57%, respectively [ see Dosage and Administration (2.5), and Use in Specific Populations (8.5)] Renal Impairment:In volunteers with mild (CLcr=50 to 80 mL/min) and moderate (CLcr=30 to 49 mL/min) renal impairment, the pharmacokinetics of a single oral dose of sildenafil citrate (50 mg) were not altered. In volunteers with severe (CLcr <30 mL/min) renal impairment, sildenafil clearance was reduced, resulting in approximately doubling of AUC and C maxcompared to age-matched volunteers with no renal impairment [ see Dosage and Administration (2.5), and Use in Specific Populations (8.6)]. In addition, N-desmethyl metabolite AUC and C maxvalues significantly increased by 200% and 79%, respectively in subjects with severe renal impairment compared to subjects with normal renal function. Hepatic Impairment:In volunteers with hepatic impairment (Child-Pugh Class A and B), sildenafil clearance was reduced, resulting in increases in AUC (85%) and C max(47%) compared to age-matched volunteers with no hepatic impairment. The pharmacokinetics of sildenafil in patients with severely impaired hepatic function (Child-Pugh Class C) have not been studied [ see Dosage and Administration (2.5), and Use in Specific Populations (8.7)]. volunteers, co-administration with the HIV protease inhibitor
- Sildenafil 120 mg is not approved by all regulatory agencies for general use.
- The maximum recommended dose for most individuals is 100 mg.
- Using high doses can lead to increased cardiovascular strain.
- Always inform your doctor of all medications to prevent interactions.
- Sildenafil may cause a sudden drop in blood pressure, especially with certain drugs.
- The medication can be used as part of a treatment plan for erectile dysfunction.
ritonavir, which is a highly potent P450 inhibitor, at steady state (500 mg
- Side effects from high doses may include dizziness, flushing, or stomach upset.
- The onset of action is typically within 30 to 60 minutes after intake.
- Patients should avoid heavy meals before taking sildenafil for quicker results.
- Overdose symptoms include chest pain, loss of vision, and fainting.
- Sildenafil is not a cure for erectile dysfunction but enhances blood flow temporarily.
- Medical review is crucial for safety when considering high-dose sildenafil.
bid) with sildenafil citrate (100 mg
| Property | Description | Typical Dose | Onset of Action | Duration of Effect | Mechanism of Action |
|---|---|---|---|---|---|
| Bioavailability | Approximately 40% | 120 mg | 30-60 minutes | Up to 6 hours | Inhibits PDE5 enzyme in smooth muscle |
| Half-life | Approximately 4 hours | N/A | N/A | N/A | Enhances nitric oxide signaling |
| Metabolism | Liver via CYP3A4 and CYP2C9 | N/A | N/A | N/A | Prevents cGMP breakdown |
| Excretion | Mainly via feces (80%), urine (13%) | N/A | N/A | N/A | Eliminates unchanged drug |
| Peak Plasma Levels | Achieved within 30-120 minutes | 120 mg | 30 minutes | N/A | Related to dose and absorption rate |
single dose) resulted in a 300% (4-fold)
| Use Case | Description | Dosage Recommendations | Special Considerations |
|---|---|---|---|
| Erectile Dysfunction (ED) | To improve blood flow to the penis during arousal | 120 mg as prescribed | Not for use with nitrates |
| Pulmonary Arterial Hypertension | Off-label for vasodilation in lungs | Under doctor guidance | Monitor blood pressure |
| Off-label Use in Sexual Dysfunction | Sometimes used in other sexual dysfunctions | As prescribed | Limited evidence for other uses |
| Enhancement of Exercise Capacity | Occasionally used in sports medicine | Not approved | Risk of adverse effects |
increase in sildenafil C maxand a
Where to Buy Sildenafil Citrate 120mg Online
Therefore, age >65, hepatic impairment and severe renal impairment are associated with increased plasma levels of sildenafil. A starting oral dose of 25 mg should be considered in those patients [ see Dosage and Administration (2.5)]. Effects of Other Drugs on Sildenafil citrate Sildenafil metabolism is principally mediated by CYP3A4 (major route) and CYP2C9 (minor route). Cimetidine (800 mg), a nonspecific CYP inhibitor, caused a 56% increase in plasma sildenafil concentrations when co-administered with sildenafil citrate (50 mg) to healthy volunteers. When a single 100 mg dose of sildenafil citrate was administered with erythromycin, a moderate CYP3A4 inhibitor, at steady state (500 mg bid for 5 days), there was a 160% increase in sildenafil C maxand a 182% increase in sildenafil AUC. 1000% (11-fold) increase in sildenafil plasma AUC.
What special precautions should I follow?
Of the four subjects who received sildenafil citrate 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 citrate 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). 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 sildenafil citrate 50 mg or matching placebo was administered in a 2-period crossover design to 20 generally healthy males with BPH. The mean subject age in this study was 63.9 years. Twenty subjects received sildenafil citrate 50 mg, but only 19 subjects received matching placebo.
What should I tell my healthcare provider before taking sildenafil?
This patient had been taking minoxidil, a potent vasodilator, during the study. For the 19 subjects who received both sildenafil citrate 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 citrate or matching placebo are shown in Figure 3. Figure 3: Mean Standing Systolic Blood Pressure Change from Baseline Blood pressure was measured after administration of sildenafil citrate at the same times as those specified for the first doxazosin study. 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 sildenafil citrate 100 mg or matching placebo was administered in a 3-period crossover design to 20 generally healthy males with BPH.
3. Shelf Life, Storage, and Dosage Form
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 sildenafil citrate 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 sildenafil citrate 50 mg). For the 20 subjects who received sildenafil citrate 100 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 100 mg sildenafil citrate or matching placebo are shown in Figure 4. Figure 4: Mean Standing Systolic Blood Pressure Change from Baseline Blood pressure was measured after administration of sildenafil citrate at the same times as those specified for the previous doxazosin studies.