Indicated for the acute relief of an attack or acute prophylaxis of angina pectoris due to coronary artery disease.
The principal pharmacological action of nitroglycerin is relaxation of vascular smooth muscle, producing a vasodilator effect on both peripheral arteries and veins with more prominent effects on the latter. Dilation of the post-capillary vessels, including large veins, promotes peripheral pooling of blood and decreases venous return to the heart, thereby reducing left ventricular enddiastolic pressure (pre-load). Arteriolar relaxation reduces systemic vascular resistance and arterial pressure (after-load).
Nitroglycerin forms free radical nitric oxide (NO), which activates guanylate cyclase, resulting in an increase of guanosine 3’5’-monophosphate (cyclic GMP) in smooth muscle and other tissues. This eventually leads to dephosphorylation of myosin light chains, which regulates thecontractile state in smooth muscle and results in vasodilation.
Absorption: Nitroglycerin is rapidly absorbed and is often used in emergency situations for this reason.
Distribution: The volume of distribution of Nitroglycerin is 3 L/kg.
Metabolism: Nitroglycerin is rapidly metabolized in the liver by hepatic enzymes to di-nitrates and mononitrates.
Elimination: Nitroglycerin is excreted by the renal route, primarily as the 2 di-nitro-metabolites.
0.5 mg Sublingual Tablet: One tablet should be dissolved under the tongue at the first sign of an acute anginal attack. The dose may be repeated approximately every five minutes, until relief is obtained. If the pain persists after a total of 3 tablets in a 15-minute period, prompt medical attention is recommended. 400 mcg spray: At the onset of an attack, 1 or 2 metered sprays should be administered under the tongue. No more than 3 metered sprays are recommended within a 15-minute period. If the chest pain persists, prompt medical attention is recommended. Anril Spray may be used prophylactically 5 to 10 minutes prior to engaging in activities which might precipitate an acute attack. Injection: The usual dose range is 10 - 200 mcg/ min. Dose up to 400 mcg/min may be required during some surgical procedures. 2.6 mg SR (Sustained Release) Tablet: Adults & Elderly Patients: Dosage should be adjusted to the requirements of the individual patient but will usually be 1 or 2 tablets taken three times daily. The lowest effective dose should be used.
Patients receiving antihypertensive drugs, beta-adrenergic blockers or phenothiazines and nitrates should be observed for possible additive hypotensive effects. Concomitant use of nitrates and alcohol may cause hypotension. The vasodilatory and hemodynamic effects of Nitroglycerin may be enhanced by concomitant administration of Aspirin.
Contraindicated in patients with early myocardial infarction, severe anemia, increased intracranial pressure & those with a known hypersensitivity to Nitroglycerin. Also contraindicated in patients who are using sildenafil citrate since sildenafil citrate has been shown to potentiate the hypotensive Effects of organic nitrates. Only the smallest dose required for Effective control of the acute anginal attack should be used. Excessive use may lead to the development of tolerance. This drug should be used with caution in patients who may be volume-depleted or are already hypotensive.
Headache, facial flushing, dizziness, nausea, vomiting, feelings of weakness, postural hypotension, reflex tachycardia etc.
Pregnancy : Pregnancy Category C. Nitroglycerin should be given to pregnant women only if clearly needed. Nursing Mothers: Caution should be exercised when Nitroglycerin Spray is administered to a nursing woman.
In the event of accidental or deliberate over dosage, toxic effects of Nitroglycerin include vomiting, restlessness, hypotension, cyanosis, methemoglobinemia, tachycardia and syncope.
Keep out of reach of children. Store in a dry place, below 25°C temperature and protected from light.
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