📌 Medicine Name:
Glyceryl Trinitrate Injection 5 mg/mL
(Also known as Nitroglycerin Injection)
📋 Description / Prescription:
Glyceryl Trinitrate Injection is a prescription-only, intravenous (IV) medication used in emergency and critical care settings to:
- Manage acute angina pectoris unresponsive to sublingual nitrates
- Control hypertension during surgery
- Treat acute heart failure and pulmonary edema
- Support post-myocardial infarction patients with ongoing ischemia
🔹 Formulation:
- Each mL contains 5 mg of glyceryl trinitrate in an alcohol/polyethylene glycol solution
- Available in ampoules or vials for dilution before IV infusion
🔬 Nature / Mechanism of Action:
Glyceryl trinitrate acts as a vasodilator by:
- Releasing nitric oxide (NO) → Activating guanylate cyclase
- Increasing cGMP → Relaxing vascular smooth muscle
- Resulting in venodilation, arterial dilation, reduced preload and afterload, and decreased myocardial oxygen demand
✅ Advantages / Therapeutic Benefits:
- ⚡ Rapid onset of action (1–2 minutes after IV start)
- 🫀 Precise titration of dose to achieve desired BP or angina control
- 💉 Suitable for use in acute coronary syndrome, cardiogenic shock, or post-operative hypertension
- ⏱️ Short half-life allows for fast adjustment or discontinuation
📦 Packaging:
- Supplied in ampoules (e.g., 5 mL) or glass vials
- Each ampoule typically contains 25 mg in 5 mL (i.e., 5 mg/mL)
- Needs dilution before IV use (e.g., in glucose or saline solution)
🌡️ Storage:
- Store at 2–8°C (refrigerated)
- Protect from light and heat
- Use diluted solutions promptly; follow stability guidelines
- Do not freeze
⚠️ Precautions:
Use with extreme caution in patients with:
- Severe hypotension or shock (unless volume status is corrected)
- Severe anemia
- Increased intracranial pressure or glaucoma
- Cardiac tamponade, restrictive cardiomyopathy, or aortic/mitral stenosis
🚫 Contraindicated with:
- Phosphodiesterase inhibitors (e.g., sildenafil, tadalafil)
- Severe hypotension or hypovolemia
Drug interactions:
- Additive effects with antihypertensives, diuretics, and alcohol
- Use cautiously with beta-blockers, calcium channel blockers, or morphine
👨⚕️ Patient Advice
- Close monitoring of blood pressure and chest pain relief
- Patient may feel headache, flushing, or dizziness—these are common and dose-related
- IV line should be protected from light
- Inform staff if experiencing severe dizziness, chest tightness, or palpitations