Sildenafil Citrate Vigora 100

Generic Name: Sildenafil Citrate Tablets

Brand Name: Sildenafil Citrate Tablets (Viagra)

English Name: Sildenafil Citrate Tablets

Pinyin Code: juyuansuanxidinafei pian (wanaike)

[Main Ingredients] The main ingredient of this product is sildenafil citrate. Chemical name: 1-[[3-(6,7-dihydro-1-methyl-7-oxo-3-propyl-1H-pyrazolo[4,3-d]pyrimidin-5-yl)-4-ethoxyphenyl]sulfonyl]-4-methylpiperazine citrate. Molecular formula: C22H30N6O4S·C6H8O7. Molecular weight: 666.70.

[Composition] Molecular formula: C28H38N6O11S.

[Description] This product is a red film-coated tablet; the core appears white after the coating is removed.

[Indications/Functions] Sildenafil is indicated for the treatment of erectile dysfunction.

[Specifications] 0.1g × 4 tablets.

[Dosage and Administration] For most patients, the recommended dose is 50 mg, taken as needed approximately 1 hour before sexual activity; however, it may be taken anywhere from 0.5 to 4 hours prior to sexual activity. Based on efficacy and tolerability, the dose may be increased to 100 mg (the maximum recommended dose) or decreased to 25 mg. The maximum frequency of dosing is once daily. Sildenafil at the recommended dose is ineffective without sexual stimulation. The following factors are associated with increased plasma sildenafil levels (AUC): age over 65 years (40% increase), hepatic impairment (e.g., cirrhosis; 80% increase), severe renal impairment (creatinine clearance <30 mL/min; 100% increase), and concomitant use of potent cytochrome P450 3A4 inhibitors [ketoconazole, itraconazole (200% increase), erythromycin (182% increase), saquinavir (210% increase)]. Since higher plasma levels may increase both therapeutic efficacy and the incidence of adverse events, a starting dose of 25 mg is appropriate for these patients.

[Adverse Reactions] Headache, flushing, dyspepsia, nasal congestion, and visual disturbances. Visual disturbances are mild and transient, manifesting primarily as altered color perception (tinged vision), increased sensitivity to light, or blurred vision.

[Contraindications] Use is contraindicated in patients taking any form of nitrate medication, whether on a regular or intermittent basis. It is also contraindicated in patients with a known hypersensitivity to any component of sildenafil (Viagra).

[Precautions] The interaction between sildenafil and nitrates affecting blood pressure can persist throughout the entire 6-hour observation period following administration. Therefore, the co-administration of sildenafil with organic nitrates or nitric oxide (NO) donors (such as sodium nitroprusside) is strictly contraindicated. Use sildenafil with caution in patients with anatomical penile deformities (e.g., angulation, cavernosal fibrosis, or Peyronie's disease) or conditions that predispose them to priapism (e.g., sickle cell anemia, multiple myeloma, or leukemia). The safety and efficacy of combining this product with other treatments for erectile dysfunction have not been studied; therefore, combination use is not recommended. In patients with existing cardiovascular risk factors, sexual activity following administration carries a risk of non-fatal or fatal cardiac events. If symptoms such as angina, dizziness, or nausea occur upon the initiation of sexual activity, the activity must be stopped. Since the product's approval for marketing abroad, there have been rare reports of prolonged erections (lasting more than 4 hours) and priapism (painful erections lasting more than 6 hours). Patients should seek immediate medical attention if an erection persists for more than 4 hours. Failure to treat priapism immediately can result in damage to penile tissue and permanent loss of erectile function. Sildenafil offers no protection against sexually transmitted diseases. Please read the package insert carefully and use the medication under the guidance of a physician.

[Use in Children] Sildenafil is not indicated for use in neonates or children. 【Use in Elderly Patients】 Sildenafil clearance is reduced in healthy elderly volunteers (≥65 years of age). Higher plasma concentrations may be associated with an increased incidence of adverse events; therefore, a starting dose of 25 mg is recommended.

【Use in Pregnant and Lactating Women】 Sildenafil is not indicated for use in women.

【Drug Interactions】 Effects of other drugs on sildenafil: In vitro studies: Sildenafil is metabolized primarily by cytochrome P450 3A4 (major pathway) and 2C9 (minor pathway); therefore, inhibitors of these isoenzymes may reduce sildenafil clearance. In vivo studies: Co-administration of sildenafil (50 mg) and cimetidine (a non-specific cytochrome P450 inhibitor, 800 mg) in healthy volunteers resulted in a 56% increase in plasma sildenafil concentrations. When a single 100 mg dose of sildenafil was co-administered with erythromycin (a specific CYP450 3A4 inhibitor; 500 mg twice daily for 5 days to reach steady state), the area under the concentration-time curve (AUC) of sildenafil increased by 182%. When a single 100 mg dose of sildenafil was co-administered with saquinavir (an HIV protease inhibitor and CYP450 3A4 inhibitor) at steady state (1200 mg three times daily), the Cmax of sildenafil increased by 140% and the AUC by 210%, while sildenafil did not affect the pharmacokinetics of saquinavir. More potent CYP450 3A4 inhibitors, such as ketoconazole and itraconazole, may produce even greater effects; sildenafil clearance is reduced when co-administered with CYP450 3A4 inhibitors (e.g., ketoconazole, erythromycin, cimetidine).

【Overdose】 In the event of overdose, standard supportive measures should be adopted as required. Since sildenafil is highly bound to plasma proteins, renal dialysis does not accelerate its clearance.

【Pharmacology and Toxicology】 This product is an oral medication for the treatment of erectile dysfunction. It is the citrate salt of sildenafil, a selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5).

[Pharmacokinetics] Sildenafil is rapidly absorbed following oral administration, with an absolute bioavailability of approximately 40%. Its pharmacokinetic parameters are dose-proportional within the recommended dosage range. Elimination occurs primarily via hepatic metabolism (mediated by the cytochrome P450 isoenzyme 3A4 pathway), yielding an active metabolite with properties similar to those of sildenafil. Co-administration with potent inhibitors of cytochrome P450 isoenzyme 3A4 (CYP450 3A4)—such as erythromycin, ketoconazole, or itraconazole—or with non-specific cytochrome P450 (CYP450) inhibitors like cimetidine may result in elevated plasma levels of sildenafil. The elimination half-life of sildenafil and its metabolites is approximately 4 hours. Following oral administration of 25–100 mg in the fasting state, peak plasma concentrations (Cmax) of 127–560 ng/mL are reached within approximately one hour. The selectivity of sildenafil and its primary metabolite (N-desmethyl metabolite) for PDE5 is approximately 50%, and the protein binding rate is 96%. At the peak plasma concentration of total sildenafil, the Cmax of free sildenafil is 22 ng/mL. Following oral or intravenous administration, sildenafil is excreted primarily as metabolites in the feces (approximately 80% of the oral dose), with a smaller fraction excreted in the urine (approximately 13% of the oral dose).

[Storage] Store in a sealed container at temperatures below 30°C.

Important Information Regarding Sexual Health Products:

Note: Oral medications for men that aid in achieving an erection require sexual stimulation to be effective; they do not induce erections automatically.

When using drugs containing sildenafil, vardenafil, tadalafil, avanafil, or dapoxetine, many users are concerned about whether the expected results will be achieved. Based on a combination of clinical data and real-world user feedback, the proportion of individuals for whom different medications prove ineffective varies slightly:

Sildenafil: Approximately 15%–20% of users do not achieve the expected results after administration.

Vardenafil: The proportion of non-responders is similar to that of Sildenafil, standing at approximately 15%–22%.

Tadalafil: Due to its longer half-life, this medication is suitable for a slightly broader range of patients; consequently, its failure rate is slightly lower, at approximately 12%–18%.

Avanafil: Characterized by a rapid onset of action and rapid metabolism, the proportion of non-responders is approximately 14%–19%.

Priligy: Specifically designed to treat premature ejaculation, this medication is more heavily influenced by individual neurological sensitivity and psychological state; as a result, its failure rate is relatively higher, at approximately 20%–25%.

It is crucial to clarify that for some individuals, a lack of efficacy is by no means an indication of a product quality issue; rather, it is the result of the interplay between the drug's mechanism of action and the individual's unique physiological and pathological conditions. Even the original brand-name products—such as Pfizer's Viagra (Sildenafil)—are known to be ineffective for a significant proportion of users (approximately 20% of men experience no effect), and this is not attributed to product quality defects. With many male enhancement products, it is common to encounter scenarios where—even with the exact same box of medication—it proves effective for one person but ineffective for another; conversely, switching to a different product may yield results for the second person while proving ineffective for the first. This store guarantees that all sexual health products sold here are 100% authentic; however, we cannot guarantee that 100% of users will achieve their desired results. We strongly urge you to carefully consider these factors before placing an order. The specific reasons vary by medication:

Sildenafil / Vardenafil / Avanafil: These three work by promoting vasodilation. Their effectiveness is influenced by individual metabolic capacity (liver and kidney function affecting the rate of drug breakdown), underlying medical conditions (e.g., diabetes or hypertension damaging blood vessels and reducing drug efficiency), and the circumstances of use (alcohol consumption can inhibit the drug's effect, while high-fat meals may delay the absorption of Sildenafil and Vardenafil). If severe arterial disease is present, the drug struggles to facilitate blood flow, naturally limiting its efficacy.

Tadalafil: Although its mechanism of action is similar to the first three, it remains in the body longer. However, its effectiveness is still influenced by factors such as individual drug sensitivity and the presence of severe prostate disease or spinal cord injuries; some individuals may experience suboptimal results due to weaker receptor binding affinity.

Priligy (Dapoxetine): This improves ejaculation control by inhibiting neurotransmitter reuptake. Its effectiveness is closely linked to individual nerve conduction efficiency, psychological state (anxiety and tension can counteract the drug's effects), and whether the dosage matches the patient's body weight and the severity of the condition. If there is abnormal nerve sensitivity or long-standing psychogenic premature ejaculation, the drug's regulatory effect may be limited.

If the results from using any of the aforementioned medications or dual-effect tablets fall short of expectations, do not arbitrarily increase the dosage, switch medications, or continue taking them blindly over the long term. Instead, consult a urologist or andrologist promptly. A doctor will assess your physical condition through a detailed consultation and, based on test results, adjust your treatment plan (e.g., optimizing dosage or changing the type of medication) or incorporate psychological interventions and behavioral training to create a solution better suited to your needs.

Specifications

Product Name: Sildenafil Citrate Tablets (Viagra) 100mg x 4 tablets (Vigora 100)

Common Name: Viagra

Ingredients: Sildenafil Citrate 100mg

Dosage Form: Tablet

Quantity: 4 tablets

Manufacturer: German Remedies

Indication: Treatment of erectile dysfunction. Dosage and Administration: For most patients, the recommended dose is 50 mg, taken as needed approximately one hour before sexual activity; however, it may be taken anywhere from 0.5 to 4 hours prior to sexual activity. Based on efficacy and tolerability, the dose may be increased to 100 mg (the maximum recommended dose) or decreased to 25 mg. The maximum dosing frequency is once daily. Sildenafil is ineffective at the recommended dose in the absence of sexual stimulation. The following factors are associated with increased plasma sildenafil levels (AUC): age over 65 years (40% increase), hepatic impairment (e.g., cirrhosis; 80% increase), severe renal impairment (creatinine clearance <30 mL/min; 100% increase), and concomitant use of potent cytochrome P450 3A4 inhibitors [ketoconazole, itraconazole (200% increase), erythromycin (182% increase), saquinavir (210% increase)]. Since higher plasma levels may increase both efficacy and the incidence of adverse events, a starting dose of 25 mg is appropriate for these patients.