Tadalafil Tablets (Vidalista)

Product Information

Drug Name

Generic Name: Tadalafil Tablets
English Name: Tadalafil Tablets

Strength: 40mg per tablet
Package Size: 100 tablets/box

Manufacturer:
Centurion Laboratories Pvt Ltd

Composition

Active Ingredient: Tadalafil

Chemical Name:
(6R,12aR)-6-(1,3-benzodioxol-5-yl)-2-methyl-2,3,6,7,12,12a-hexahydropyrazino[1',2':1,6]pyrido[3,4-b]indole-1,4-dione

Molecular Formula: C₂₂H₁₉N₃O₄

Molecular Weight: 389.41

Description

This product is a yellow film-coated tablet. After removing the coating, it appears white or almost white.

Indications

Tadalafil is indicated for:

1. Male Erectile Dysfunction (ED)

2. Erectile Dysfunction associated with Benign Prostatic Hyperplasia (BPH)

3. Adult Pulmonary Arterial Hypertension (PAH, WHO Group 1)

• Improves exercise capacity

• Used for idiopathic/heritable PAH and PAH associated with connective tissue disease

• 40mg dosage is specifically used for PAH treatment

Dosage and Administration

1. Pulmonary Arterial Hypertension (PAH – Standard 40mg Regimen)

Recommended dose:
40mg once daily by oral administration.

• May be taken with or without food.

• Swallow the tablet whole.

• Do not split or crush the tablet.

Initial Dosage Recommendations:

Normal kidney function:

• Start directly with 40mg once daily.

Mild to moderate renal impairment:
(Creatinine clearance 31–80mL/min)

• Start with 20mg once daily.

• Increase to 40mg once tolerated.

Severe renal impairment:
(Creatinine clearance <30mL/min)

• Not recommended.

• Avoid use in dialysis patients.

Liver Function:

• Mild to moderate hepatic impairment (Child-Pugh A/B):

• 20mg once daily recommended.

• Maximum dose should not exceed 40mg.

• Severe hepatic impairment (Child-Pugh C):

• Contraindicated.

Elderly Patients (>65 years):

• No routine dosage adjustment required.

2. Erectile Dysfunction (ED Dosage)

On-Demand Use:

• Starting dose: 10mg

• Take approximately 30 minutes before sexual activity.

• May increase to 20mg or reduce to 5mg depending on response.

• Maximum frequency: once daily.

• Effect may last up to 36 hours.

Once-Daily Use:

• Initial dose: 2.5mg once daily.

• May increase to 5mg once daily.

• Take at approximately the same time each day.

Contraindications

Do not use tadalafil in the following situations:

1. Nitrate Medications

Combination with any nitrate medication is strictly prohibited, including:

• Short-acting nitrates

• Long-acting nitrates

• Oral nitrates

• Sublingual nitrates

• Spray nitrates

Combination may cause:

• Severe hypotension

• Fainting

• Life-threatening cardiovascular events

2. Guanylate Cyclase (GC) Stimulators

Do not combine with GC stimulators such as:

• Riociguat

The combination may significantly enhance blood-pressure-lowering effects.

3. Allergy

Do not use if allergic to:

• Tadalafil

• Any inactive ingredients

4. Severe Cardiovascular Disease

Contraindicated in patients with:

• Myocardial infarction within the past 90 days

• Unstable angina

• Heart failure ≥ Class II within 6 months

• Severe uncontrolled arrhythmia

• Low blood pressure (<90/50mmHg)

• Stroke within the past 6 months

Adverse Reactions

Common Side Effects (≥10%)

• Headache

• Facial flushing

• Indigestion

• Nasal congestion

• Back pain

• Muscle pain

Less Common Side Effects (1–10%)

• Dizziness

• Visual disturbances:

• Blurred vision

• Blue-green color perception changes

• Increased light sensitivity

• Eye redness

• Nausea

• Diarrhea

• Skin rash

• Palpitations

• Increased heart rate

• Low blood pressure

Rare but Serious Side Effects (<1%)

Cardiovascular:

• Myocardial infarction

• Sudden cardiac death

• Stroke

• Chest pain

Eye-related:

• Non-arteritic anterior ischemic optic neuropathy (NAION)

• Visual field defects

• Retinal vascular occlusion

Hearing:

• Sudden hearing reduction or loss

• May be accompanied by tinnitus or dizziness

Genitourinary:

• Prolonged erection (>4 hours)

• Priapism (>6 hours), which may cause permanent erectile tissue damage

Systemic:

• Severe allergic reactions:

• Urticaria

• Stevens-Johnson syndrome

• Exfoliative dermatitis

• Migraine

• Seizures

• Temporary memory loss

Precautions

1. Blood Pressure Risk

Combination with:

• Alpha-blockers (such as terazosin)

• Antihypertensive drugs

• Alcohol

may increase blood-pressure reduction and cause:

• Dizziness

• Fainting

The 40mg dosage carries a higher blood-pressure risk.

Do not combine with alpha-blockers.

2. Prolonged Erection

Seek immediate medical attention if:

• Erection lasts more than 4 hours

If lasting more than 6 hours, it is a medical emergency and may permanently damage erectile tissue.

Use with caution in patients with:

• Sickle cell anemia

• Multiple myeloma

• Leukemia

• Penile anatomical abnormalities

3. Vision and Hearing Problems

Stop use immediately and seek emergency medical care if experiencing:

• Sudden vision loss

• Sudden hearing loss

4. Cardiovascular Safety

Sexual activity itself may carry cardiovascular risks.

Patients advised to avoid sexual activity due to heart disease should not use tadalafil.

Stop sexual activity and seek medical attention if experiencing:

• Chest pain

• Severe dizziness

• Shortness of breath

5. Liver and Kidney Function

Do not use 40mg tadalafil in:

• Severe liver impairment (Child-Pugh C)

• Severe renal impairment (creatinine clearance <30mL/min)

6. Bleeding Risk

Tadalafil may affect platelet aggregation.

Use caution in patients with:

• Bleeding disorders

• Active peptic ulcers

7. Sexually Transmitted Diseases

Tadalafil does not protect against:

• HIV

• Syphilis

• Other sexually transmitted infections

Protective measures should still be used.

8. Special Populations

Women and Children:

Not indicated.

Elderly Patients:

No routine dosage adjustment required, but elderly patients may be more sensitive to blood-pressure effects.

Drug Interactions

1. Strong CYP3A4 Inhibitors

Examples:

• Ketoconazole

• Itraconazole

• Erythromycin

• Clarithromycin

• Ritonavir

May increase tadalafil blood levels.

For 40mg dosage:

• Dose reduction to 20mg once daily may be required.

2. CYP3A4 Inducers

Examples:

• Rifampin

• Carbamazepine

• Phenytoin

May reduce tadalafil effectiveness.

Combination is not recommended.

3. Nitrates / GC Stimulators

Absolutely contraindicated.

4. Alcohol

Alcohol may increase blood-pressure-lowering effects.

Large amounts of alcohol with 40mg tadalafil may increase the risk of:

• Dizziness

• Fainting

Avoid excessive alcohol consumption.

Pharmacology and Toxicology

Mechanism of Action

Tadalafil is a selective and reversible PDE5 inhibitor.

During sexual stimulation:

1. Nitric oxide (NO) is released.

2. Guanylate cyclase is activated.

3. cGMP levels increase.

4. Smooth muscle in the corpus cavernosum relaxes.

5. Blood flow increases, resulting in erection.

For PAH patients:

• PDE5 inhibition in pulmonary vessels causes pulmonary artery relaxation.

• Reduces pulmonary pressure.

• Improves exercise capacity.

Duration of Action

• ED dosage: up to 36 hours

• PAH 40mg daily dosage: reaches steady state after continuous administration.

Toxicology

• Long-term high-dose use has not shown significant liver or kidney toxicity.

• Reproductive toxicity:

• 20mg/day for 9 months may slightly reduce sperm concentration.

• Testosterone levels are not affected.

Pharmacokinetics

Absorption

• Rapidly absorbed after oral administration.

• Peak concentration reached approximately 2 hours after fasting administration.

• High-fat meals may delay absorption by about 1 hour but do not reduce bioavailability.

Distribution

• Protein binding: approximately 94%

• Mainly distributed in:

• Lungs

• Liver

• Kidneys

Metabolism

• Mainly metabolized by liver enzyme CYP3A4.

• Active metabolites have weaker activity than the original compound.

Elimination

• Feces: approximately 61%

• Urine: approximately 36%

Half-life:

• Approximately 17.5 hours

Steady state:

• Achieved after about 5 days of 40mg once-daily administration.

Storage Conditions

Store at:

• Room temperature (10–30℃)

• Keep sealed

• Protect from light and moisture

Product Specifications