Glyceryl Trinitrate Bristol Laboratories (Glyceryl Trinitrate)

Glyceryl Trinitrate Bristol Laboratories is indicated for several cardiovascular situations where rapid relief of chest pain or reduction of cardiac workload is required.

• Acute angina pectoris attacks, providing quick symptom relief.
• Prophylactic use to prevent angina episodes before physical exertion or stress.
• Management of heart failure with associated ischemic symptoms.
• Treatment of hypertensive emergencies when rapid vasodilation is needed.
• Adjunct therapy during cardiac catheterisation to prevent spasm.
• Use in combination with other anti‑anginal agents under medical supervision.

Side‑effect profiles for sublingual glyceryl trinitrate include both frequent, mild reactions and rarer, more serious events.

Common

• Headache, often described as throbbing, due to vasodilation.
• Flushing or warmth in the face and neck.
• Dizziness or light‑headedness, especially when standing quickly.
• Low blood pressure (hypotension) causing mild faintness.
• Nausea or upset stomach.
• Blurred vision.

Serious

• Severe hypotension leading to syncope.
• Reflex tachycardia with rapid heart rate.
• Methemoglobinemia, a rare disorder affecting oxygen transport.
• Allergic skin reaction such as rash or urticaria.
• Chest pain worsening despite treatment.

Before prescribing Glyceryl Trinitrate Bristol Laboratories, clinicians consider several precautionary factors to minimise risk and optimise benefit.

• Known hypersensitivity to nitrates or any component of the tablet.
• Severe anemia or elevated methemoglobin levels.
• Recent use of phosphodiesterase‑5 inhibitors (e.g., sildenafil) due to risk of profound hypotension.
• Unstable hemodynamic status, such as shock or severe hypotension.
• Concomitant severe aortic stenosis where rapid vasodilation may be hazardous.
• Pregnancy and lactation status, as safety data are limited.
• Elderly patients who may be more sensitive to blood‑pressure changes.

Glyceryl Trinitrate can interact with other medicines, altering its effectiveness or increasing adverse effects.

Avoid

• Phosphodiesterase‑5 inhibitors (sildenafil, tadalafil, vardenafil) because combined vasodilation may cause dangerous hypotension.
• Other nitrate preparations (isosorbide dinitrate, nitroglycerin patches) that can lead to additive nitrate tolerance or severe blood‑pressure drops.
• Certain antihypertensive agents (e.g., alpha‑blockers) that may amplify hypotensive effects.

Use with caution

• Beta‑blockers, which may mask tachycardia signs of low blood pressure.
• Calcium‑channel blockers, especially dihydropyridines, that can increase vasodilatory response.
• Diuretics, as volume depletion may enhance hypotensive risk.
• Alcohol, which can potentiate dizziness and low blood pressure.