Isosorbide Mononitrate Tablet (Imdur / Elantan): Uses, Dosage & Side Effects in Pakistan

Isosorbide Mononitrate Tablet (Imdur / Elantan) Uses, Dosage, Side Effects & Price in Pakistan

1. Quick Info (Mukhtasir Maloomat)

2. What is Isosorbide Mononitrate? (Imdur kya hai)

Isosorbide Mononitrate (ISMN) is a commonly prescribed nitrate medicine in Pakistan for the prevention of angina pectoris. It is marketed under the brand names Imdur (AstraZeneca) and Elantan; local generics are also available.

ISMN releases nitric oxide (NO) in the body → activates guanylate cyclase → cGMP → smooth muscle relaxation → venodilation + mild arterial dilation (afterload reduction) → reduces myocardial oxygen demand → prevents angina.

CRITICAL: This medicine is NOT for ACUTE angina attacks. Use sublingual GTN (glyceryl trinitrate) for an acute attack. ISMN is for PREVENTION only.

3. Uses (Fayde / Kis kaam aati hai)

• Angina pectoris prophylaxis
• Stable angina maintenance therapy
• Left ventricular failure (adjunct therapy)

4. Who Should Take (Kis ko leni chahiye)

• Stable angina patients (cardiology se confirmed diagnosis)
• Patients needing long-term angina prevention alongside other cardiac medications
• Left ventricular failure adjunct patients (as prescribed by cardiologist)

5. When NOT to Take (Kab nahi leni chahiye)

• With sildenafil (Viagra), tadalafil (Cialis), vardenafil, avanafil — ABSOLUTE CONTRAINDICATION (FATAL hypotension)
• Acute angina attack — this is a preventive medicine, not for acute relief
• Severe hypotension (low blood pressure)
• If allergic to nitrates
• Hypertrophic obstructive cardiomyopathy (HOCM)

6. Dosage (Kitni leni hai)

• As prescribed — doctor's guidance is essential

• As prescribed — typically once daily SR formulation in morning

• Do not exceed the recommended limit

• If you miss a dose, take it as soon as you remember. If the next dose is close, skip the missed dose. Never take a double dose.

7. How to Take (Kaise leni hai)

• SR tablets must NEVER be broken or chewed — swallow whole

• Take SR formulation after waking in the morning — provides a natural overnight nitrate-free interval

• Can be taken with or without food

• For the first dose sit or lie down — there is a risk of hypotension

8. Best Time (Kab leni chahiye)

• Take SR formulation once in the morning — an overnight gap is essential to prevent tolerance

• A 10-12 hour nitrate-free interval is required every day — to prevent tolerance

9. Empty Stomach or After Food (Khali pait ya khane ke baad)

Both with food and without are fine. If the stomach is sensitive, taking it after food is better. Avoid alcohol — additive hypotension can occur.

10. Warnings (Ihtiyat)

• ABSOLUTELY DO NOT use with sildenafil (Viagra), tadalafil (Cialis), vardenafil, avanafil — risk of SEVERE FATAL hypotension. This combination is CONTRAINDICATED — a minimum gap of 24-48 hours is required. Tell your doctor if you are using these medicines.

• DO NOT use this medicine during an acute angina attack — use sublingual GTN

• Nitrate tolerance can develop with daily use — morning dosing of SR formulation and an overnight nitrate-free interval are essential

11. Precautions (Ahm ehtiyaat)

• Store in a cool, dry place — away from moisture
• Keep away from direct sunlight
• Keep out of the reach of children

• Dizziness may occur the first time — avoid driving until the body adjusts

12. Side Effects (Nuksanat)

• Headache, Hypotension/dizziness, Flushing, Reflex tachycardia, Nausea

• Severe hypotension — especially with PDE5 inhibitors (POTENTIALLY FATAL) — seek emergency help immediately
• Syncope / fainting — see a doctor immediately
• Methaemoglobinaemia (rare — high dose) — seek emergency help immediately

13. Drug Interactions (Dawaon ke sath reaction)

• PDE5 inhibitors (sildenafil, tadalafil, vardenafil, avanafil) — SEVERE FATAL hypotension — ABSOLUTELY CONTRAINDICATED
• Antihypertensives — additive hypotension — dose adjustment may be needed
• Alcohol — vasodilation + hypotension — avoid
• Ergotamine — vasospasm — avoid
• Heparin — nitrates may reduce anticoagulant effect

Blood pressure can drop severely — combination with sildenafil is dangerous.

14. When to See Doctor (Kab doctor ke paas jayein)

• Severe headache that does not settle even after 2 weeks
• Severe dizziness / fainting (hypotension)
• Rapid or irregular heartbeat
• Chest pain worsening despite treatment — EMERGENCY
• If sildenafil or tadalafil has been taken with it — go to emergency room immediately

15. Alternatives (Sasti Dusri Dawaein)

16. Price in Pakistan (Price kitni hai)

17. FAQs (Aksar poochay jane walay sawalat)

Q: Imdur kis kaam aata hai?

A: Isosorbide Mononitrate (Imdur/Elantan) is used for PREVENTION of angina pectoris. It is NOT for acute angina attacks — use sublingual GTN for an acute attack. Always get a doctor's prescription.

Q: Isosorbide Mononitrate ke side effects kya hain?

A: Common side effects include headache (very common — improves after 1-2 weeks), dizziness, flushing, and nausea. A serious side effect is severe hypotension with sildenafil/tadalafil — can be FATAL.

Q: Isosorbide Mononitrate sildenafil ke sath kyun nahi lena chahiye?

A: Both are vasodilators — the combination can cause a very severe blood pressure drop (severe hypotension) which can be FATAL. ABSOLUTELY CONTRAINDICATED.

Q: Isosorbide Mononitrate price Pakistan mein kya hai?

A: Imdur (AstraZeneca), Elantan, and local generics are available. Price varies by pharmacy and strength — confirm at a local pharmacy.

Q: Angina ka dora ho to kya lein?

A: Do NOT take ISMN during an acute attack — place sublingual GTN (glyceryl trinitrate) under the tongue. If pain does not resolve within 15 minutes, go to hospital emergency immediately.

18. Medical Review (Medical jaiza)

Compiled by the PakVita Editorial Team · AI-assisted drafting with editorial review · Sourced from DRAP, WHO, BNF · Last updated: 2026-06-17

19. Disclaimer (Zaroori tanbeeh)

The information on this page is for awareness only. It is not medical advice. Always consult your doctor or pharmacist before taking any medicine. PakVita is not responsible for any harm.