📋 Indications & Clinical Dosage
*Prophylaxis and treatment of stable angina (second-line therapy):*
Adult: Initially 5-10 mg twice daily, then increased if tolerated to 40 mg twice daily; usual dose 10-20 mg twice daily, use lower initial dose regimen if patient susceptible to headache.
Children: Not recommended.
⛔ Contraindications
Acute pulmonary oedema, cardiogenic shock, hypovolaemia, left ventricular failure with low filling pressures, severe hypotension
⚠️ Precautions & Warnings
Acute myocardial infarction with acute left ventricular failure and low filling pressures, diverticular disease (risk of fistula formation or bowel perforation), G6PD deficiency, heart failure (class III-IV), hyperkalaemia, low systolic blood pressure
🔄 Drug Interactions
Hypotensive agents, TCADs.
⚠️ Adverse Reactions / Side Effects
Cutaneous vasodilation with flushing, dizziness, headache (especially on initiation), increase in heart rate (at high doses), nausea, rectal bleeding, vomiting, weakness, angioedema, hypotension, myalgia, oralulceration. Rare: Abdominal pain, anal ulceration, cholestasis, GI ulceration, GI haemorrhage, hepatitis, jaundice, pruritus, rash, skin ulceration
🤰 Pregnancy & Lactation Safety
Pregnancy Risk:
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.