Vigore 100

Generic Name:

Sildenafil Citrate

Product Name:

Vigore 100

Active Ingredient

The main active ingredient of this product is Sildenafil Citrate.

Chemical name:

1-{4-Ethoxy-3-(6,7-dihydro-1-methyl-7-oxo-3-propyl-1H-pyrazolo[4,3-d]pyrimidin-5-yl)phenylsulfonyl}-4-methylpiperazine citrate

Molecular formula:

C22H30N6O4S · C6H8O7

Molecular weight:

666.70

Composition:

Molecular formula:

C28H38N6O11S

Appearance

This product is a red film-coated tablet. After removing the coating, the tablet appears white.

Indications / Therapeutic Use

Sildenafil Citrate is indicated for the treatment of erectile dysfunction (ED).

It helps men achieve and maintain an erection sufficient for satisfactory sexual activity.

Strength and Packaging

Specification:

0.1g × 4 tablets

(Each tablet contains 100mg Sildenafil Citrate)

Dosage and Administration

For most patients, the recommended dose is:

50mg taken approximately 1 hour before sexual activity.

However, it may also be taken anytime within:

0.5 to 4 hours before sexual activity.

Based on effectiveness and tolerability, the dosage may be adjusted:

• Increased to 100mg (maximum recommended dose)

• Reduced to 25mg

Maximum dosage:

Do not take more than once daily.

Sildenafil requires sexual stimulation to work. It will not automatically cause an erection without sexual stimulation.

Patients Requiring Dose Adjustment

The following factors may increase sildenafil plasma concentration (AUC):

• Age over 65 years: approximately 40% increase

• Liver impairment (such as cirrhosis): approximately 80% increase

• Severe renal impairment
  (creatinine clearance <30ml/min): approximately 100% increase

• Concomitant use of strong CYP450 3A4 inhibitors, including:

• Ketoconazole

• Itraconazole (approximately 200% increase)

• Erythromycin (approximately 182% increase)

• Saquinavir (approximately 210% increase)

Because higher plasma levels may increase both therapeutic effects and adverse reactions, these patients should start with:

25mg sildenafil

Adverse Reactions

Common adverse reactions include:

• Headache

• Facial flushing

• Indigestion

• Nasal congestion

• Visual disturbances

Visual disturbances are usually:

• Mild

• Temporary

Symptoms may include:

• Reduced color perception

• Increased sensitivity to light

• Blurred vision

Contraindications

This product should not be used in:

Patients taking nitrate medications

Patients who are taking any type of nitrate medication, whether regularly or intermittently, should not use sildenafil.

Patients allergic to sildenafil

Patients who are allergic to sildenafil citrate or any component of the product should not take this medicine.

Precautions

Interaction with Nitrates

The blood pressure-lowering interaction between sildenafil and nitrate medications may continue throughout the entire 6-hour observation period after administration.

Therefore:

The combination of sildenafil with organic nitrates or nitric oxide donor drugs (such as sodium nitroprusside) is strictly contraindicated.

Patients Who Should Use Sildenafil With Caution

Sildenafil should be used cautiously in patients with:

Anatomical penile abnormalities

Including:

• Penile curvature

• Cavernosal fibrosis

• Peyronie's disease

Conditions associated with increased risk of prolonged erection

Including:

• Sickle cell anemia

• Multiple myeloma

• Leukemia

Cardiovascular Warnings

The safety and effectiveness of combining sildenafil with other erectile dysfunction treatments have not been established. Combined use is not recommended.

In patients with existing cardiovascular risk factors, sexual activity after taking sildenafil may increase the risk of non-fatal or fatal cardiac events.

If symptoms occur during sexual activity, such as:

• Angina (chest pain)

• Dizziness

• Nausea

sexual activity should be stopped immediately.

Prolonged Erection Warning

After approval and marketing of sildenafil, rare cases of:

• Prolonged erection lasting more than 4 hours

• Painful erection lasting more than 6 hours (priapism)

have been reported.

If an erection lasts longer than 4 hours, seek immediate medical attention.

If priapism is not treated promptly, penile tissue damage may occur and may result in permanent loss of erectile function.

Sexually Transmitted Diseases

Sildenafil does not provide protection against sexually transmitted diseases (STDs/STIs).

Please read the instructions carefully and use according to medical advice.

Pediatric Use

Sildenafil is not indicated for newborns or children.

Elderly Patients

In healthy elderly volunteers aged 65 years and above, sildenafil clearance is reduced.

Higher blood concentrations may increase the risk of adverse reactions.

Therefore:

A starting dose of 25mg is recommended for elderly patients.

Use in Pregnancy and Breastfeeding

Sildenafil is not indicated for women.

Drug Interactions

Effects of Other Drugs on Sildenafil

In vitro studies:

Sildenafil is mainly metabolized through:

• Cytochrome P450 3A4 (major pathway)

• Cytochrome P450 2C9 (minor pathway)

Therefore, inhibitors of these enzymes may reduce sildenafil clearance.

Clinical studies:

When healthy volunteers took:

Sildenafil 50mg + Cimetidine 800mg

(a non-specific CYP450 inhibitor)

the plasma concentration of sildenafil increased by approximately:

56%

When:

Sildenafil 100mg + Erythromycin 500mg twice daily for 5 days

were taken together:

• Sildenafil AUC increased by approximately 182%

When:

Sildenafil 100mg + Saquinavir 1200mg three times daily

were combined:

• Saquinavir Cmax increased by approximately 140%

• AUC increased by approximately 210%

Sildenafil did not significantly affect the pharmacokinetics of saquinavir.

Stronger CYP450 3A4 inhibitors such as:

• Ketoconazole

• Itraconazole

may produce greater increases in sildenafil concentration.

When sildenafil is used together with CYP450 3A4 inhibitors, including:

• Ketoconazole

• Erythromycin

• Cimetidine

the clearance of sildenafil may decrease.

Overdose

In cases of overdose, standard supportive medical treatment should be provided as necessary.

Because sildenafil has a high plasma protein binding rate, kidney dialysis is unlikely to increase its elimination.

Pharmacology and Toxicology

Sildenafil is an oral medication used for the treatment of erectile dysfunction.

It is the citrate salt of sildenafil and acts as a selective inhibitor of:

cGMP-specific phosphodiesterase type 5 (PDE5).

Pharmacokinetics

After oral administration, sildenafil is rapidly absorbed.

The absolute bioavailability is approximately:

40%

Within the recommended dosage range, pharmacokinetic parameters are dose proportional.

Sildenafil is mainly eliminated through:

hepatic metabolism via CYP450 3A4 pathway

It produces an active metabolite with properties similar to sildenafil.

Strong CYP450 3A4 inhibitors, including:

• Erythromycin

• Ketoconazole

• Itraconazole

and non-specific CYP450 inhibitors such as:

• Cimetidine

may increase plasma sildenafil levels.

The elimination half-life of sildenafil and its metabolites is approximately:

4 hours

When taken on an empty stomach at doses of:

25–100mg

maximum plasma concentration is reached approximately:

1 hour after administration

Cmax range:

127–560 ng/ml

Sildenafil and its main metabolite:

N-desmethyl sildenafil

have approximately:

50% selectivity for PDE5

Protein binding:

96%

At maximum plasma concentration:

Free sildenafil Cmax:

22 ng/ml

After oral or intravenous administration:

• Approximately 80% of the dose is eliminated through feces as metabolites.

• Approximately 13% is eliminated through urine.

Storage Conditions

Store in a sealed container.

Keep below:

30°C

Store in a dry place away from direct sunlight.

Product Specifications

Product Name:
Vigore 100

Generic Name:
Sildenafil Citrate

Active Ingredient:
Sildenafil Citrate 100mg

Dosage Form:
Tablet

Package Size:
4 tablets

Manufacturer:
German Remedies

Indication:
For the treatment of erectile dysfunction.

Dosage Instructions

For most patients:

Recommended dose:

50mg approximately 1 hour before sexual activity.

May be taken:

0.5–4 hours before sexual activity.

Depending on efficacy and tolerance:

• Increase to 100mg (maximum recommended dose)

• Reduce to 25mg

Maximum frequency:

Once daily only.

Sildenafil requires sexual stimulation to be effective.

Patients with increased sildenafil exposure risk factors, including:

• Age ≥65 years

• Liver impairment

• Severe kidney impairment

• Strong CYP450 3A4 inhibitor use

should consider a lower starting dose:

25mg.