Zenegra 50 Mg (Sildenafil Citrate)

What is Zenegra 50 mg?

• Zenegra 50 is an oral tablet for erectile dysfunction (ED).
• Each film-coated tablet contains 50 mg of sildenafil citrate.
• Sildenafil belongs to the PDE-5 inhibitor drug class.
• It helps adult men achieve and maintain a firm erection.
• Sildenafil is the original and most widely used ED medicine.
• It has been in clinical use since 1998.
• Zenegra is made by Alkem Laboratories in India.
• Alkem is one of India’s largest pharmaceutical companies.
• The tablet is swallowed whole with water.
• It is taken only when needed, not daily.
• The medicine works only during sexual stimulation.
• It does not increase sexual desire or libido.
• It does not cure the underlying cause of ED.
• It does not treat premature ejaculation.
• It offers no protection against HIV or other STIs.
• It is not a hormone, steroid, or aphrodisiac.
• Zenegra 50 is intended for adult men only.
• Women and anyone under 18 must not use it.
• ED can signal heart, hormonal, or vascular disease.
• A full medical assessment should precede any ED treatment.

How It Works (Mechanism of Action)

Sildenafil restores the body’s natural erection pathway:

1. Sexual stimulation triggers nitric oxide release in penile tissue.
2. Nitric oxide activates an enzyme called guanylate cyclase.
3. This enzyme raises cyclic guanosine monophosphate (cGMP) levels.
4. cGMP relaxes smooth muscle in the corpus cavernosum.
5. Relaxed muscle allows penile arteries to widen.
6. Blood flows in and fills the erectile chambers.
7. Expanding tissue compresses the veins, trapping blood inside.
8. This produces and sustains a firm erection.
9. An enzyme called PDE-5 breaks cGMP down.
10. Rapid breakdown makes the erection fade too early.
11. Sildenafil blocks PDE-5, so cGMP stays elevated longer.
12. Blood flow is therefore maintained during sexual activity.

Why visual side effects occur: PDE-6 is a related enzyme found in the retina. Sildenafil affects PDE-6 alongside PDE-5. This explains the blue-tinged vision some men notice. The effect is temporary and harmless in most cases. It is less likely at 50 mg than at 100 mg.

Key point: Without sexual stimulation, no nitric oxide is released. The medicine then has nothing to act on.

Dosage Guide

Patient Group	Recommended Dose	Maximum Frequency	Key Notes
Adult men, first-time use	50 mg	Once in 24 hours	This is the standard starting dose
Adult men, good response at 50 mg	50 mg	Once in 24 hours	Stay at the lowest effective dose
Adult men, inadequate response	100 mg	Once in 24 hours	Zenegra 100 is available for this
Adult men, side effects at 50 mg	25 mg	Once in 24 hours	Use a 25 mg product instead
Men aged 65 and over	25 mg starting dose	Once in 24 hours	Clearance is slower; start lower
Mild to moderate liver impairment	25 mg starting dose	Once in 24 hours	Requires medical supervision
Severe liver impairment	Not recommended	–	Sildenafil should be avoided
Severe kidney impairment (CrCl under 30 mL/min)	25 mg starting dose	Once in 24 hours	Requires specialist supervision
Taking CYP3A4 inhibitors (ketoconazole, erythromycin, clarithromycin)	25 mg	Once in 24 hours	These drugs raise sildenafil blood levels
Taking ritonavir or cobicistat	25 mg	Once in 48 hours	Strict maximum; interaction is significant
Taking alpha-blockers (tamsulosin, doxazosin)	25 mg starting dose	Once in 24 hours	Stabilise the alpha-blocker dose first
Absolute daily maximum	100 mg	One dose per 24 hours	Never exceed 100 mg in a day

Timing: Take one dose 30 to 60 minutes before sexual activity. Duration: The effect can last up to 4 to 5 hours. Nitrate interval: Allow at least 24 hours after a dose before any nitrate. Food: A high-fat meal can delay onset by about one hour. Two tablets: Do not take two tablets unless your doctor prescribed 100 mg. Missed dose: Not applicable. This medicine is used only as needed.

How to Take It

1. Take the tablet exactly as your doctor prescribed.
2. Check you have the tablets, not the Lido Spray.
3. Swallow the tablet whole with a glass of water.
4. Do not chew, crush, or split the tablet.
5. Take it 30 to 60 minutes before planned sexual activity.
6. Take it on an empty stomach for the fastest onset.
7. Avoid heavy or high-fat meals before dosing.
8. A fatty meal can delay onset by about one hour.
9. Sexual stimulation is required for the medicine to work.
10. The effect lasts around 4 to 5 hours.
11. Take no more than one tablet in 24 hours.
12. Do not combine it with any other ED medicine.
13. Do not take a second tablet if the first seems weak.
14. Wait a full 24 hours before considering another dose.
15. Contact your doctor if it fails on several attempts.
16. Do not share your tablets with anyone else.

Precautions

Absolute Contraindications – Do Not Use If You

• Take any nitrate medicine in any form.
• Nitrates include glyceryl trinitrate and isosorbide mononitrate or dinitrate.
• This covers nitrate sprays, patches, and sublingual tablets.
• Take nicorandil, a nitrate-like anti-anginal medicine.
• Use amyl nitrite or butyl nitrite recreationally (“poppers”).
• Take riociguat or another guanylate cyclase stimulator.
• Are allergic to sildenafil or any tablet excipient.
• Have had a heart attack or stroke within 6 months.
• Have unstable angina or angina during sexual intercourse.
• Have severe heart failure classified as NYHA class IV.
• Have severe low blood pressure below 90/50 mmHg.
• Have severe uncontrolled high blood pressure.
• Have severe liver disease, such as decompensated cirrhosis.
• Have retinitis pigmentosa or another inherited retinal disease.
• Have previously lost vision from non-arteritic anterior ischaemic optic neuropathy (NAION).
• Have been advised to avoid sexual activity for cardiac reasons.
• Are a woman, a child, or an adolescent under 18.

Critical: Nitrates plus sildenafil can cause a fatal drop in blood pressure. Never combine them. Allow at least 24 hours between a dose and any nitrate medicine.

Conditions to Disclose to Your Doctor

Tell your doctor before use if you have or had:

• Any heart disease, arrhythmia, or heart valve problem.
• A previous heart attack, stroke, or bypass surgery.
• Angina, or any prescription for nitrates in the past.
• High blood pressure or low blood pressure.
• Liver disease or hepatitis of any type.
• Kidney disease or reduced kidney function.
• Any eye disease or sudden vision loss previously.
• Hearing loss, tinnitus, or other ear disorders.
• Sickle cell anaemia, leukaemia, or multiple myeloma.
• Any bleeding disorder or clotting problem.
• An active or recent stomach ulcer.
• A penile deformity such as Peyronie’s disease or angulation.
• Cavernosal fibrosis or a previous prolonged erection.
• An enlarged prostate, or treatment for it.
• Diabetes, especially if poorly controlled.
• Pulmonary arterial hypertension treated with sildenafil or tadalafil.
• Recent or planned surgery, including dental procedures.

Also disclose every medicine, supplement, and herbal product you take.

Food and Drink Precautions

Item	Effect	Recommendation
High-fat meals	Delay absorption and onset	Take on an empty stomach or after a light meal
Grapefruit and grapefruit juice	Raise sildenafil blood levels	Avoid entirely on dosing days
Alcohol	Impairs erection and lowers blood pressure	Limit strictly; avoid binge drinking
Excess caffeine	May worsen palpitations and headache	Reduce intake around dosing
Water	No interaction	Use a full glass to swallow the tablet
Grapefruit-containing supplements	Same risk as the fruit	Check labels and avoid
Seville oranges and pomelo	May affect the same enzyme pathway	Best avoided on dosing days

Before-Use Safety Checklist

Confirm every point below before each dose:

• ☐ A doctor has prescribed this medicine for me.
• ☐ I have the tablets, not the Lido Spray.
• ☐ I have taken no nitrate medicine in the past 24 hours.
• ☐ I have not used poppers or amyl nitrite.
• ☐ I have taken no other ED medicine today.
• ☐ I have not taken a dose in the last 24 hours.
• ☐ I take no interacting antifungal or antibiotic.
• ☐ My doctor knows all my current medicines.
• ☐ My heart is fit enough for sexual activity.
• ☐ I have not eaten a heavy or fatty meal.
• ☐ I have avoided grapefruit juice today.
• ☐ I have limited or avoided alcohol.
• ☐ The blister is sealed and undamaged.
• ☐ The strength on the pack matches my prescription.
• ☐ The expiry date has not passed.
• ☐ I know the emergency warning signs listed below.

Side Effects

Side effects are dose-related. They are generally less frequent at 50 mg than at 100 mg.

Side Effect	Frequency	What To Do
Headache	Common	Usually mild; rest and hydrate
Facial flushing or warmth	Common	Settles as the drug wears off
Indigestion or heartburn	Common	Avoid heavy or spicy meals
Blocked or runny nose	Common	Temporary; no treatment usually needed
Dizziness	Common	Sit or lie down; do not drive
Blurred or blue-tinged vision	Common	Avoid driving; tell your doctor
Light sensitivity	Common	Avoid bright screens and sunlight
Nausea	Common	Take with a light snack next time
Back pain or muscle ache	Common	Usually resolves within 24 hours
Rapid or pounding heartbeat	Less common	Rest; seek advice if it persists
Nosebleed	Less common	Apply pressure; report if repeated
Dry mouth or altered taste	Less common	Sip water regularly
Skin rash or itching	Less common	Stop use and contact your doctor
Low blood pressure symptoms	Less common	Stop use; seek medical advice
Ringing in the ears	Less common	Report to your doctor
Fainting or near-fainting	Rare	Stop use; seek medical care
Chest pain	Rare	Emergency; see section 8
Priapism (erection over 4 hours)	Rare	Emergency; see section 8
Sudden vision loss (NAION)	Rare	Emergency; stop use permanently
Sudden hearing loss or tinnitus	Rare	Emergency; stop use immediately
Seizure	Very rare	Emergency; call for help
Severe skin reaction with blistering	Very rare	Emergency; stop use immediately

Most common effects are mild and short-lived. Report anything persistent or severe to your doctor.

Drug Interactions – Avoid With

Never combine (dangerous):

• All nitrates: glyceryl trinitrate, isosorbide mononitrate, isosorbide dinitrate.
• Nicorandil, a nitrate-like anti-anginal medicine.
• Amyl nitrite and butyl nitrite (“poppers”).
• Riociguat and other soluble guanylate cyclase stimulators.
• Other PDE-5 inhibitors: tadalafil, vardenafil, avanafil, udenafil.
• Zenegra 100 or any other sildenafil product.
• Sildenafil brands prescribed for pulmonary hypertension.
• Alprostadil or any other erectile dysfunction treatment.

Use only with medical supervision and dose adjustment:

• Alpha-blockers: tamsulosin, doxazosin, alfuzosin, terazosin.
• Antifungals: ketoconazole, itraconazole, voriconazole.
• Macrolide antibiotics: erythromycin, clarithromycin.
• HIV protease inhibitors: ritonavir, saquinavir, cobicistat-boosted regimens.
• Cimetidine, an acid-reducing medicine.
• Bosentan, used in pulmonary hypertension.
• Blood pressure medicines, including amlodipine and diuretics.
• Clonidine and other centrally acting blood pressure medicines.
• Any medicine for an enlarged prostate.

May reduce effectiveness:

• Rifampicin, an antibiotic used for tuberculosis.
• Carbamazepine, phenytoin, and phenobarbital.
• St John’s Wort, a herbal antidepressant.

Always show your doctor a full list of your medicines.

Emergency Warning Signs

Stop the medicine and seek emergency care immediately if you experience:

1. An erection lasting longer than 4 hours (priapism).
2. A painful erection that will not subside.
3. Chest pain, pressure, or tightness during or after sex.
4. Pain spreading to the jaw, neck, or left arm.
5. Sudden loss of vision in one or both eyes.
6. Sudden decrease or loss of hearing.
7. Ringing in the ears with dizziness.
8. Fainting, collapse, or severe persistent dizziness.
9. Severe shortness of breath.
10. Swelling of the face, lips, tongue, or throat.
11. Widespread rash with blistering or peeling skin.
12. A seizure or convulsion.
13. Signs of stroke: sudden weakness, slurred speech, facial droop.

Tell emergency staff you have taken sildenafil. State the strength as 50 mg. They must not give you nitrate medicines. Untreated priapism can cause permanent erectile damage within hours.

Why Choose Zenegra 50 mg

Genuine advantages:

• 50 mg is the correct starting dose for sildenafil.
• Most men respond well at this strength.
• Starting here reduces the chance of side effects.
• Headache and flushing are less frequent than at 100 mg.
• Blue-tinged vision is also less likely at this dose.
• Your doctor can adjust up or down from this point.
• Made by Alkem Laboratories, a major Indian manufacturer.
• Alkem is publicly listed with international regulatory experience.
• Zenegra is a long-established sildenafil brand.
• Contains sildenafil citrate, the most established ED molecule.
• Sildenafil has been in clinical use since 1998.
• Its interaction profile is the best characterised in the class.
• Provides an effect window of 4 to 5 hours.
• Taken only when needed, not on a daily schedule.

Honest limitations you should know:

• A fatty meal delays onset by about an hour.
• The effect lasts hours, not the 36 hours tadalafil offers.
• Blue-tinged vision is more common than with newer drugs.
• This is a conventional tablet with no format advantage.
• Chewable and jelly options exist if swallowing is difficult.
• The brand name is shared with a lidocaine spray.

Consider a different product or strength if:

• You are aged 65 or over, where 25 mg is the better start.
• You have liver or kidney impairment.
• You take alpha-blockers or CYP3A4 inhibitors.
• You have difficulty swallowing tablets.
• You want cover across a whole weekend.
• You have had visual side effects on sildenafil before.

Bottom line: Sildenafil at the dose most men should begin with, from a major manufacturer. For a first ED prescription, that combination is a sound choice.

Storage Instructions

• Store below 30°C in a cool, dry place.
• Protect tablets from direct sunlight and heat.
• Keep tablets sealed in the original blister until use.
• Do not store in the bathroom or near a sink.
• Moisture and humidity can degrade the tablets.
• Do not transfer tablets into unlabelled containers.
• Keep the original pack for the drug name and strength.
• Never mix tablets of different strengths in one container.
• Never store these alongside Zenegra Lido Spray.
• The two products are entirely different medicines.
• Do not freeze or refrigerate this product.
• Keep it out of the sight and reach of children.
• Accidental ingestion by a child is a medical emergency.
• Check the expiry date printed on the pack.
• Never use tablets after the expiry date.
• Discard damaged, cracked, or discoloured tablets.
• Dispose of unused medicine through a pharmacy take-back scheme.
• Do not flush tablets or throw them in household waste.

Medical Disclaimer

This content is for information only. It is not medical advice. Zenegra 50 mg is a prescription-only medicine. 50 mg is the recommended starting dose of sildenafil for most adult men. This product is different from Zenegra Lido Spray, which contains lidocaine and treats premature ejaculation. Nitrate medicines must be avoided for at least 24 hours after a dose. Use it only under a qualified doctor’s supervision. Always read the manufacturer’s package insert before use.