Glyceryl Trinitrate

Nitroglycerin, NTG

Mechanism :

The principal pharmacological action is relaxation of vascular smooth muscle, and consequent dilatation of peripheral arteries and veins, especially the latter. Dilatation of the veins promotes peripheral pooling of blood and decreases venous return to the heart, thereby reducing left ventricular end-diastolic pressure and pulmonary capillary wedge pressure (preload). Arteriolar relaxation reduces systemic vascular resistance, systolic arterial pressure, and mean arterial pressure (afterload).

Indication :

• Hypertension during and after cardiac surgery
• Congestive Heart Failure

Contraindications :

Allergic reactions to organic nitrates are extremely rare. Contraindicated in patients who are allergic to it.

Dosing :

IV Infusion: Start 0.25-0.5 mcg/kg/min and increase by 0.5-1 mcg/kg every 3-5 minutes until response. Monitor BP and heart rate. Tolerance may develop. Maximum dose: 20 mcg/min.

Oral administration is not FDA approved.

Adverse Effect :

Tachycardia, vomiting, hypotension, nausea, headache, dizziness, retrosternal discomfort, xerostomia, flushing, muscle twitching, restlessness, palpitations and paradoxical bradycardia.

Interaction :

Calcium-Channel Blockers, Antihypertensive Agents, Phenothiazines and Tricyclic Antidepressants: Orthostatic hypotension may occur.

Renal Dose :

Hepatic Dose :