Nitroglycerin Orifarm (Glyceryl Trinitrate)

Nitroglycerin Orifarm acts on the coronary and peripheral vascular system to relieve and prevent angina episodes.

• Acute angina pectoris: provides rapid relief of chest pain during an attack.
• Prophylaxis of angina: reduces the frequency of angina episodes when taken before exertion.
• Chronic stable angina: helps control symptoms during daily activities and exercise.

• Glyceryl trinitrate releases nitric oxide in vascular smooth muscle, activating guanylate cyclase and increasing cyclic GMP levels. Elevated cGMP leads to relaxation of smooth muscle cells, causing dilation of coronary arteries and peripheral veins, which decreases myocardial oxygen demand and improves blood flow to the heart.

Nitroglycerin Orifarm may cause a range of adverse reactions.

Common Side Effects

• Headache: throbbing pain often described as a pressure sensation.
• Flushing: warmth and redness of the face or neck.
• Dizziness or light‑headedness: due to reduced blood pressure.
• Hypotension: mild drop in systolic blood pressure.
• Tachycardia: compensatory increase in heart rate.
• Nausea: occasional upset stomach.

Serious or Rare Side Effects

• Severe hypotension: marked drop in blood pressure leading to fainting.
• Syncope: sudden loss of consciousness.
• Myocardial infarction: rare but possible in vulnerable patients.
• Allergic reaction: rash, itching, or swelling.
• Methemoglobinemia: rare blood disorder causing reduced oxygen delivery.

Before prescribing Nitroglycerin Orifarm, clinicians should consider several safety factors.

• Cardiovascular assessment: evaluate blood pressure and heart rate.
• Concomitant nitrates: avoid use with other nitrate preparations.
• Phosphodiesterase‑5 inhibitors: do not combine with sildenafil, tadalafil, or similar agents.
• Anemia or hypovolemia: use with caution in patients with low blood volume.
• Abrupt discontinuation: taper to prevent rebound angina.
• Store at room temperature: keep in the original container, protect from moisture and light.

Nitroglycerin Orifarm can interact with several drug classes, requiring careful management.

Major Interactions (Avoid)

• Phosphodiesterase‑5 inhibitors (e.g., sildenafil, tadalafil): risk of profound hypotension.
• Other nitrates (e.g., isosorbide dinitrate): additive vasodilatory effect.
• Riociguat: synergistic vasodilation leading to severe blood pressure fall.

Moderate Interactions (Monitor Closely)

• Antihypertensives (e.g., ACE inhibitors, beta‑blockers): may enhance blood pressure lowering.
• Diuretics: increased risk of volume depletion and hypotension.
• Alcohol: can potentiate vasodilatory effects.
• Antidiabetic agents: monitor for altered glucose control due to hemodynamic changes.