Viagra 100mg (Sildenafil Citrate)

1. Name of the Medicinal Product

Viagra 100 mg film-coated tablets 

2. Qualitative and Quantitative Composition

Each film-coated tablet contains sildenafil citrate equivalent to 100 mg of sildenafil. 

Excipients of known effect: Each tablet contains 3.5 mg lactose (as monohydrate) 

3. Pharmaceutical Form

Film-coated tablet.

Appearance: Blue, rounded diamond-shaped film-coated tablets, marked “VIAGRA” on one side and “VGR 100” on the other. 

4. Clinical Particulars

4.1 Therapeutic Indications

Viagra is indicated in adult men with erectile dysfunction (ED), which is the inability to achieve or maintain a penile erection sufficient for satisfactory sexual performance.

Important: In order for Viagra to be effective, sexual stimulation is required. 

4.2 Posology and Method of Administration

Adults (18-64 years):

• Recommended dose: 50mg taken as needed, approximately one hour before sexual activity

• Based on efficacy and tolerability, dose may be increased to 100mg or decreased to 25mg

• Maximum recommended dose: 100mg

• Maximum dosing frequency: once per day

• If taken with food, onset of activity may be delayed compared to fasted state 

Elderly (≥65 years):

• Dose adjustments are not required 

Renal Impairment:

• Mild to moderate (CrCl 30-80 mL/min): Standard dosing applies

• Severe (CrCl <30 mL/min): Consider 25mg starting dose, may increase step-wise to 50mg then 100mg as necessary 

Hepatic Impairment (e.g., cirrhosis):

• Consider 25mg starting dose, may increase step-wise to 50mg then 100mg as necessary 

Patients taking CYP3A4 inhibitors (e.g., ritonavir, erythromycin, ketoconazole):

• Starting dose of 25mg should be considered 

Patients on alpha-blocker therapy:

• Patients should be stabilized on alpha-blocker therapy before initiating sildenafil

• Initiate sildenafil at 25mg dose 

Method of Administration: For oral use. Take approximately 1 hour before sexual activity. May be taken anywhere from 30 minutes to 4 hours before sexual activity. 

4.3 Contraindications

Viagra is contraindicated in patients:

• With hypersensitivity to sildenafil or any excipients

• Taking nitrates (e.g., nitroglycerin, isosorbide mononitrate/dinitrate) or nitric oxide donors (e.g., amyl nitrite) – co-administration can cause severe hypotension 

• Taking guanylate cyclase stimulators (e.g., riociguat) 

• For whom sexual activity is inadvisable due to severe cardiovascular disorders (e.g., unstable angina, severe cardiac failure) 

• With loss of vision in one eye due to NAION (non-arteritic anterior ischemic optic neuropathy), regardless of previous PDE5 inhibitor exposure 

Contraindicated patient subgroups (safety not established):

• Severe hepatic impairment

• Hypotension (blood pressure <90/50 mmHg)

• Recent history of stroke or myocardial infarction

• Known hereditary degenerative retinal disorders (e.g., retinitis pigmentosa) 

Pediatric population: Not indicated for individuals below 18 years of age. 

4.4 Mechanism of Action

Sildenafil is a potent and selective inhibitor of phosphodiesterase type 5 (PDE5) , the enzyme responsible for degradation of cyclic guanosine monophosphate (cGMP) in the corpus cavernosum of the penis. 

When sexual stimulation causes local release of nitric oxide (NO), PDE5 inhibition by sildenafil causes increased cGMP levels in the corpus cavernosum, resulting in smooth muscle relaxation and increased blood flow into the penile tissues. This produces an erection.

Important: Viagra has no effect in the absence of sexual stimulation. 

4.5 Pharmacokinetics

4.6 Side Effects

Common (≥1/100 to <1/10):

• Headache (most common) 

• Flushing (facial redness) 

• Nasal congestion 

• Dizziness 

• Dyspepsia (indigestion) 

Uncommon:

• Nausea, vomiting

• Visual disturbances (blurred vision, blue/green color tinge, increased sensitivity to light) 

Rare but serious:

• Prolonged erection (priapism): Seek emergency treatment if erection lasts >4 hours 

• Sudden vision loss: May be a sign of NAION – stop Viagra and seek immediate medical attention 

• Sudden hearing loss or decrease 

• Severe hypotension (especially with nitrates)

5. Drug Interactions

6. Warnings and Precautions

Cardiovascular:

• Sexual activity poses a cardiac risk for patients with pre-existing cardiovascular disease

• Use with caution in patients with left ventricular outflow obstruction (e.g., aortic stenosis)

• Not recommended in patients with severe cardiac failure, unstable angina, recent MI or stroke 

Priapism:

• Patients should seek emergency treatment if an erection lasts more than 4 hours 

Ophthalmic:

• Sudden vision loss in one or both eyes requires immediate medical attention

• Use with caution in patients with NAION history or “crowded” optic disc 

Otic:

• Sudden decrease or loss of hearing – seek prompt medical attention 

Bleeding disorders / Active peptic ulcer:

• Use with caution as limited safety data available 

7. Pregnancy and Lactation

Pregnancy Category: B 

Viagra is not indicated for use in women. No adequate and well-controlled studies in pregnant women. 

Breastfeeding: Excretion in breast milk unknown – use caution. 

8. Storage

• Store below 30°C (86°F) in a dry place, protected from light 

• Keep out of reach of children 

• Do not use after expiry date

9. Legal Category

Prescription Only Medicine (POM) – Requires a valid prescription from a licensed healthcare provider.