Isordil Tablet: Uses, Dosage & Side Effects in Pakistan

Isordil Tablet (Isosorbide Dinitrate) Uses, Dosage, Side Effects & Price in Pakistan

1. Quick Info (Mukhtasir Maloomat)

2. What is Isordil? (Isordil kya hai)

Isordil (Isosorbide Dinitrate — ISDN) is a prescription nitrate medicine used in Pakistan for angina pectoris prophylaxis and acute relief. It releases nitric oxide (NO) in the body which relaxes blood vessels — affecting both veins and arteries — thereby reducing the load on the heart and relieving angina. The sublingual 5mg tablet is placed under the tongue for acute angina.

3. Uses (Fayde / Kis kaam aata hai)

• Angina pectoris prophylaxis
• Acute angina relief — sublingual 5mg tablet
• Left ventricular failure (adjunct therapy — doctor supervised)
• Oesophageal spasm (off-label use — same smooth muscle relaxation mechanism)

4. Who Should Take (Kis ko leni chahiye)

• Adults with diagnosed angina pectoris (stable angina) under cardiologist or physician care
• Patients requiring short-term nitrate therapy for acute anginal episodes
• Patients with left ventricular failure as part of a broader cardiac treatment plan
• NOT for patients already taking PDE5 inhibitors (sildenafil, tadalafil, etc.)

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

• Currently using PDE5 inhibitors (sildenafil/Viagra, tadalafil/Cialis, vardenafil/Levitra) — ABSOLUTELY CONTRAINDICATED
• Riociguat (Adempas) — CONTRAINDICATED
• Severe hypotension (systolic BP < 90 mmHg)
• Hypovolemia (dehydration / fluid loss)
• Acute circulatory failure / shock
• Hypertrophic obstructive cardiomyopathy (worsens outflow obstruction)
• Constrictive pericarditis / cardiac tamponade
• Allergy to nitrates or isosorbide compounds

6. Dosage (Kitni leni hai)

• As directed by your doctor — typically 10mg–40mg multiple times daily depending on indication
• NITRATE TOLERANCE RULE: Asymmetric dosing is required — e.g., 8AM and 1PM — an overnight nitrate-free interval (10-12 hours) must be maintained to prevent tolerance

• 5mg sublingual tablet — placed under the tongue; onset 2-5 minutes
• If no relief after 5 minutes, take a second dose; if no relief after 3 doses, SEEK EMERGENCY IMMEDIATELY

• 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)

• Oral tablets: swallow with water
• Sublingual tablets: place UNDER the tongue — do not swallow; allow to dissolve
• Sit or lie down after the first dose — risk of BP drop
• Follow the asymmetric dosing schedule — maintain the overnight nitrate-free interval

8. Best Time (Kab leni chahiye)

• Prophylaxis: at the times specified by your doctor — e.g., morning and midday
• Acute angina: immediately when chest pain occurs — use the sublingual tablet

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

• Oral tablets may be taken with or after food. Sublingual tablets may be used at any time — immediately when an angina attack occurs.

10. Warnings (Ihtiyat)

• Sildenafil (Viagra, Revatio), tadalafil (Cialis, Adcirca), vardenafil, avanafil — must NEVER be taken with any nitrate. Together they lower blood pressure to a life-threatening level. If sildenafil has been taken recently, inform the emergency room.

• Taking Isordil multiple times daily can cause tolerance to develop — effectiveness decreases. The solution is an overnight nitrate-free interval (10-12 hours). Asymmetric dosing ensures this. Strictly follow your doctor's dosing schedule.

• Headache is very common in the first 1-2 weeks. This is normal and usually improves on its own. It can be managed with paracetamol. If it remains severe after 2 weeks, consult your doctor.

• Do not stand up after the first dose — BP can drop and fainting may occur. Sit or lie down initially.

• Alcohol + nitrate = severe hypotension risk — avoid completely

11. Precautions (Ahm ehtiyaat)

• Dizziness may occur especially during the first few doses — assess your fitness to drive

• Heat + nitrate = increased hypotension risk — stay well hydrated

• Below 30°C, in a cool and dry place
• Keep away from direct sunlight and moisture
• Store sublingual tablets in the original airtight container — potency can be lost in non-original containers
• Keep well out of the reach of children

12. Side Effects (Nuksanat)

• Headache — bukhaar jaisa sar dard
• Hypotension / dizziness — BP girna, chakkar aana
• Flushing — skin redness and warmth
• Reflex tachycardia — rapid heartbeat (reflex response to vasodilation)
• Palpitations
• Nausea

• Severe hypotension
• Syncope / behoshi
• Methaemoglobinaemia (rare — high dose — bluish skin color, confusion, breathlessness)

13. Drug Interactions (Dawaon ke sath reaction)

• PDE5 inhibitors (sildenafil, tadalafil, vardenafil, avanafil) — ABSOLUTELY CONTRAINDICATED — risk of fatal hypotension; never use this combination
• Riociguat — CONTRAINDICATED — same cGMP pathway — severe hypotension
• Antihypertensives (BP medicines) — additive blood pressure lowering; monitor
• Alcohol — additive vasodilation — severe hypotension possible
• Ergotamine — vasospasm; avoid concomitant use
• Diuretics — volume depletion → worse hypotension
• Tricyclic antidepressants — additive hypotension

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

• Chest pain not resolved after 3 sublingual doses (15 minutes) — SEEK EMERGENCY IMMEDIATELY
• Severe dizziness, near-fainting, or fainting (hypotension)
• Headache still severe after 2 weeks — dose adjustment may be needed
• Rapid or irregular heartbeat (palpitations / tachycardia)
• Bluish skin colour, confusion (methaemoglobinaemia — rare)
• If you are taking sildenafil or any Viagra-type medicine and Isordil has also been prescribed — INFORM YOUR DOCTOR IMMEDIATELY

15. Alternatives (Dusri Dawaein)

16. Price in Pakistan (Price kitni hai)

Price varies by pharmacy and city. Check the current price at licensed online pharmacies (dawaai.pk, sehat.com.pk).

17. FAQs (Aksar poochay jane walay sawalat)

Q: Isordil kis kaam aata hai?

A: Isordil (Isosorbide Dinitrate) is used for angina pectoris prophylaxis and acute angina relief. It is a nitrate that relaxes blood vessels and reduces the load on the heart. It is an Rx medicine — do not take without a doctor.

Q: Isordil ke side effects kya hain?

A: The most common side effect is headache — it is more frequent in the first 1-2 weeks and then improves. Dizziness (BP drop) also occurs — sit or lie down after a dose.

Q: Isordil aur ISMN mein kya farq hai?

A: Isosorbide Dinitrate (ISDN/Isordil) is shorter acting and requires multiple daily doses. Isosorbide Mononitrate (ISMN) has better bioavailability and a once-daily SR formulation — often preferred for prophylaxis. Both are nitrates.

Q: Isordil price Pakistan mein kya hai?

A: Isordil (Isosorbide Dinitrate) price in Pakistan varies by strength and pack size. Confirm the current price at your local pharmacy.

Q: Isordil sildenafil ke saath kyun dangerous hai?

A: Isordil (nitrate) and sildenafil (Viagra) both lower blood pressure excessively — taking them together can drop blood pressure so severely that the brain or heart does not receive enough blood, posing a life-threatening risk. This combination is ABSOLUTELY CONTRAINDICATED.

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.