Product Description
Drug Class: Organic Nitrate / Vasodilator | Form: Standard-Release Oral Tablet | Prescription Status: Prescription Only (Rx) — DRAP Registered
What is Monis 40mg Tablet? Monis 40mg contains Isosorbide Mononitrate — an organic nitrate vasodilator used exclusively for prevention and long-term management of chronic stable angina caused by coronary artery disease. Unlike the extended-release XR formulation, Monis 40mg is a standard-release tablet requiring careful twice-daily dosing with doses taken asymmetrically — not evenly spaced — to maintain a mandatory nitrate-free interval that prevents tolerance development. Like all nitrate formulations, it has no role in treating acute chest pain attacks where fast-acting sublingual nitrates are required. It must be used consistently under cardiological supervision for effective long-term angina prevention.
What is Monis 40mg Used For?
- Chronic stable angina prevention — recurring chest pain from reduced coronary blood flow (سینے کے درد کی روک تھام)
- Long-term management of coronary artery disease related chest pain (دل کی شریانوں کی بیماری)
- Reducing frequency and severity of angina episodes (انجائنا کے دوروں کی تعداد اور شدت کم کرنا)
- Reducing cardiac workload in established ischaemic heart disease
- Adjunctive therapy alongside beta-blockers or calcium channel blockers for angina control
How Does it Work? Isosorbide Mononitrate releases nitric oxide in vascular smooth muscle — activating guanylate cyclase to increase cyclic GMP, causing smooth muscle relaxation and vasodilation. Venous dilation reduces blood returning to the heart, decreasing preload and cardiac workload. Coronary artery dilation simultaneously improves blood flow and oxygen delivery to heart muscle. Together these effects prevent the oxygen supply-demand mismatch responsible for angina pain. The asymmetric twice-daily dosing schedule — morning and early afternoon — maintains effective daytime protection while creating a nitrate-free overnight interval that prevents tolerance.
Dosage and Administration
⚠️ Never take doses evenly spaced — doses must be taken asymmetrically to preserve the nitrate-free overnight interval. Never crush or chew. Never stop suddenly after long-term use. This tablet does NOT treat acute angina attacks — always carry a fast-acting sublingual nitrate for acute episodes.
| Indication | Usual Adult Dose | Timing | Notes |
|---|---|---|---|
| Chronic stable angina | 20 – 40mg | First dose on waking | Swallow whole with water |
| Chronic stable angina | 20 – 40mg | Second dose 7 hours later | Never take evening dose — preserves nitrate-free interval |
| Severe angina | Up to 40mg twice daily | As above timing | Adjusted by cardiologist |
Active Ingredients
| Ingredient | Strength |
|---|---|
| Isosorbide Mononitrate | 40mg |
Who Should NOT Take Monis 40mg?
- Allergy to Isosorbide Mononitrate, any organic nitrate, or nitrite compound
- Currently taking PDE-5 inhibitors — Sildenafil (Viagra), Tadalafil, or Vardenafil — life-threatening blood pressure drop
- Severe hypotension — systolic blood pressure below 90mmHg
- Hypovolaemia — significant dehydration or blood loss
- Severe anaemia
- Hypertrophic obstructive cardiomyopathy
- Constrictive pericarditis or cardiac tamponade
- Closed-angle glaucoma
- Severe liver impairment
- Acute myocardial infarction with low filling pressures — specialist assessment required
Side Effects
Common: Throbbing headache — most common especially when starting treatment (سر درد — عام طور پر چند دنوں میں کم ہو جاتا ہے), facial flushing and warmth (گرمی کا احساس), dizziness especially on standing quickly, mild nausea, mild weakness — most side effects reduce after the first few days as the body adjusts.
Serious — Stop and seek emergency help immediately: Severe sudden drop in blood pressure with fainting — particularly if PDE-5 inhibitor taken (بلڈ پریشر کا اچانک گرنا — فوری ہسپتال جائیں), methaemoglobinaemia — bluish discolouration of lips and fingertips with breathing difficulty (ہونٹوں کا نیلا ہونا — فوری مدد لیں), severe persistent headache unresponsive to Paracetamol, worsening frequency of angina attacks suggesting tolerance development, severe allergic reaction with widespread rash and facial swelling.
Drug Interactions
| Medicine | Interaction |
|---|---|
| PDE-5 inhibitors (Sildenafil, Tadalafil, Vardenafil) | Life-threatening severe hypotension — absolutely contraindicated; never combine under any circumstances |
| Antihypertensives / beta-blockers / calcium channel blockers | Additive blood pressure lowering — increased hypotension and dizziness risk |
| Other nitrates (sublingual GTN) | Additive vasodilation — monitor blood pressure carefully during acute use |
| Dihydroergotamine | Nitrates increase Ergotamine absorption — increased vasospasm risk |
| Antidepressants (TCAs) | Additive hypotensive effect — increased dizziness and fainting risk |
| Heparin | Isosorbide Mononitrate may reduce Heparin anticoagulant effect — monitor closely |
| Alcohol (شراب) | Severely increases vasodilation and hypotension risk — avoid completely |
Storage: Store below 25°C in a cool, dry place. Protect from moisture and direct sunlight. Keep in original packaging. Keep out of reach of children (بچوں کی پہنچ سے دور رکھیں). Do not use after expiry date.
FAQs
Q: Why must Monis 40mg doses be taken asymmetrically rather than evenly spaced? Even spacing of nitrate doses maintains continuous nitrate exposure — causing the body to develop tolerance within 24 hours where the medicine loses its effectiveness completely. Taking both doses in the first half of the day creates a natural nitrate-free overnight interval that preserves full effectiveness the next morning.
Q: Can Monis 40mg be used instead of sublingual GTN during an acute chest pain attack? No — Monis 40mg is a slow-acting prevention medicine only. It cannot relieve an acute angina attack. Always carry a fast-acting sublingual nitrate spray or tablet as prescribed by your cardiologist for immediate treatment of sudden chest pain.
Q: What is the difference between Monis 40mg and Monis XR 60mg? Monis 40mg is standard-release requiring careful asymmetric twice-daily dosing to preserve the nitrate-free interval. Monis XR 60mg is extended-release — taken once daily in the morning, it gradually releases medicine throughout the day while naturally providing a nitrate-free overnight interval without requiring dose timing management.
Medical Disclaimer: This information is for general awareness only and does not replace medical advice. Always consult a qualified doctor or pharmacist before taking any prescription medicine.
Reviewed By
Dr. Rasheed Ahmad, Pharm-D (Baqai Medical University, Karachi) — Pharmaceutical Consultant and Medical Content Specialist. This description has been reviewed for clinical accuracy, regulatory compliance, and patient safety before publication.