Nitrocor (Glyceryl Trinitrate)

Nitrocor (glyceryl trinitrate) is used in the anti‑anginal drug class to manage coronary ischemia.

• Acute angina pectoris: rapid relief of chest pain by dilating coronary vessels.
• Prophylaxis of angina pectoris: reduces the frequency of angina attacks during exertion.
• Heart failure: improves symptoms in patients with left ventricular dysfunction by decreasing preload and afterload.

• Glyceryl trinitrate is enzymatically converted to nitric oxide within vascular smooth‑muscle cells. The nitric oxide activates soluble guanylate cyclase, raising cyclic GMP levels, which relaxes smooth muscle, dilates veins and arteries, lowers preload and afterload, and consequently reduces myocardial oxygen demand, with the most pronounced effect in the venous system.

Nitrocor may cause a range of adverse reactions, from mild to severe.

Common Side Effects

• Headache: throbbing pain often occurring shortly after administration.
• Flushing: warmth and redness of the face or neck.
• Hypotension: transient drop in blood pressure causing dizziness.
• Tachycardia: compensatory increase in heart rate.
• Nausea: mild gastrointestinal discomfort.

Serious or Rare Side Effects

• Severe hypotension: marked blood pressure fall leading to syncope.
• Methemoglobinemia: elevated methemoglobin causing cyanosis.
• Allergic reaction: rash, itching, or swelling.
• Chest pain rebound: worsening angina after nitrate tolerance.
• Vision disturbances: blurred vision or photophobia.

When prescribing Nitrocor, clinicians should observe several safety considerations.

• Cardiovascular status: avoid in patients with severe hypotension or recent myocardial infarction.
• Concomitant nitrate therapy: do not combine with other long‑acting nitrates to prevent additive hypotension.
• Phosphodiesterase‑5 inhibitors: contraindicated due to risk of profound hypotension.
• Pregnancy and lactation: use only if potential benefit outweighs unknown risks.
• Driving and operating machinery: advise caution if dizziness occurs.
• Store at below 25°C: keep in original container, protect from moisture and light.

Nitrocor interacts with several drug classes that can modify its hemodynamic effects.

Major Interactions (Avoid)

• Phosphodiesterase‑5 inhibitors (e.g., sildenafil): may cause severe hypotension.
• Other nitrates or nitrites: additive vasodilatory effect leading to dangerous blood pressure drop.
• Uncontrolled hypertension medications: may blunt therapeutic effect.

Moderate Interactions (Monitor Closely)

• Antihypertensives (ACE inhibitors, ARBs, beta‑blockers): may enhance blood pressure lowering.
• Diuretics: increase risk of volume depletion and hypotension.
• Alcohol: can potentiate vasodilatory response.
• Calcium channel blockers: may augment hypotensive effect.