TabletsClinical Overview
Nitroglycerin (Glyceryl Trinitrate) is an organic nitrate vasodilator on the WHO Model List of Essential Medicines. It is denitrated intracellularly to release nitric oxide (NO), stimulating guanylate cyclase, increasing intracellular cyclic GMP, and activating protein kinase G, producing profound relaxation of vascular smooth muscle with preferential dilation of large systemic veins (reducing cardiac preload and myocardial oxygen demand) and epicardial coronary arteries. Indicated for acute relief and prophylaxis of angina pectoris attacks, perioperative hypertension, and acute pulmonary edema.
Active Pharmaceutical Ingredients
Verified Clinical References
Usage Guidelines
For controlled-release tablets: swallow whole with water on an empty stomach (1 hour before or 2 hours after meals); do not crush or chew. A nitrate-free interval of 10 to 12 hours daily is required to prevent nitrate tolerance. For sublingual tablets: place under tongue at the onset of chest pain; do not swallow.
General Administration Advice: Adhere strictly to the prescribed dosage, frequency, and treatment course. For oral medications, swallow with sufficient water. Never stop antibiotics, psychiatric medications, or antihypertensives abruptly without clinical direction.
Possible Side Effects
Common: Throbbing headache ("nitrate headache"), flushing, dizziness, postural hypotension, reflex tachycardia, weakness. Rare/Severe: Severe hypotension, syncope, methemoglobinemia, and paradoxically worsened angina.
*Note: Individual physiological responses vary. While many patients experience few or no side effects, notify your treating physician if adverse reactions persist or if hypersensitivity (angioedema, skin rash, dyspnea) occurs.
Precautions & Warnings
Absolute contraindication: Concomitant use with phosphodiesterase-5 (PDE-5) inhibitors (sildenafil, tadalafil, vardenafil) causes catastrophic, life-threatening hypotension and cardiovascular collapse. Contraindicated in severe aortic stenosis, hypertrophic cardiomyopathy, and severe anemia. Nitrate tolerance develops rapidly without a daily nitrate-free interval.
Schedule H (Prescription Required)
This medication is scheduled under statutory drug regulatory frameworks (CDSCO / Drugs & Cosmetics Rules). Dispensing requires a valid medical prescription from a registered medical practitioner. Self-medication or unsupervised dosage adjustment carries significant clinical risks.
Medical Disclaimer: Statutory Clinical Disclaimer: The information provided is for educational and price-transparency purposes only and does not constitute medical advice, clinical diagnosis, or treatment recommendations. Always consult a registered medical practitioner or qualified cardiologist/pharmacist before initiating, altering, or substituting any cardiovascular medication.