📋 Indications & Clinical Dosage
*Prophylaxis of angina, Adjunct in congestive heart failure:*
Adult: Initially 20 mg 2-3 times a day, alternatively initially 40 mg twice daily, increased if necessary up to 120 mg daily in divided doses.
*Prophylaxis of angina, Adjunct in congestive heart failure (for patients who have not previously had a nitrate):*
Adult: Initially 10 mg twice daily, increased if necessary up to 120 mg daily in divided doses.
Children: Not recommended.
⛔ Contraindications
Hypersensitivity to nitrates; hypotensive conditions and hypovolaemia; hypertrophic cardiomyopathy; aortic stenosis; cardiac tamponade; constrictive pericarditis; mitral stenosis; toxic pulmonary oedema; head trauma; cerebral haemorrhage; cerebrovascular disease; marked anaemia.
⚠️ Precautions & Warnings
Hypothyroidism, malnutrition, hypothermia, recent history of myocardial infarction, heart failure due to obstruction, hypoxaemia or other ventilation and perfusion abnormalities, susceptibility to angle-closure glaucoma, metal-containing transdermal systems should be removed before magnetic resonance imaging procedures,
cardioversion, or diathermy, avoid abrupt withdrawal, monitor blood pressure and heart rate during IV infusion.
🔄 Drug Interactions
Sildenafil, tadalafil, vardenafil, ethanol, heparin, alteplase, ergot alkaloids.
⚠️ Adverse Reactions / Side Effects
Postural hypotension, tachycardia, paradoxical bradycardia, throbbing headache, dizziness, nausea, vomiting, heartburn, flushing, syncope, temporary hypoxaemia, rash. Rare: angle-closure glaucoma. Injection Specific side-effects include severe hypotension, diaphoresis, apprehension, restlessness, muscle twitching, retrosternal discomfort, palpitation, abdominal pain, prolonged administration has been associated with methaemoglobinaemia.
🤰 Pregnancy & Lactation Safety
Pregnancy Risk:
Caution advised, avoid unless potential benefit outweighs risk.
Lactation / Breastfeeding:
Caution advised
📚 Official Regulatory & Clinical References
- Drug Regulatory Authority of Pakistan (DRAP): Drug Registration, S.R.O. Price Gazettes & National Essential Medicines List (NEML).
- World Health Organization (WHO): Collaborating Centre for Drug Statistics Methodology (ATC/DDD Index).
- Formulary Standards: British National Formulary (BNF) & Pakistan National Formulary (PNF) guidelines.