Nitroglycerin (medication)

Nitroglycerin, also known as glyceryl trinitrate, is a medication used for the treatment of angina pectoris, heart failure, and high blood pressure. It is also used in the management of myocardial infarction and Raynaud's phenomenon. Nitroglycerin is available in various forms, including sublingual, oral, transdermal, and intravenous formulations.

Medical Uses

Nitroglycerin is primarily used to relieve chest pain associated with angina pectoris. It works by dilating the blood vessels, which reduces the workload on the heart and improves blood flow to the myocardium. This medication is also used in the treatment of heart failure and hypertension.

Angina Pectoris

For angina pectoris, nitroglycerin is often administered sublingually for rapid relief of chest pain. It can also be used prophylactically before activities that may provoke angina.

Heart Failure

In cases of heart failure, nitroglycerin helps to reduce the symptoms by decreasing the preload and afterload on the heart, thus improving cardiac output.

Hypertension

Nitroglycerin is used in the management of hypertensive emergencies due to its potent vasodilatory effects.

Mechanism of Action

Nitroglycerin is a nitrovasodilator that releases nitric oxide (NO) in the body. NO activates the enzyme guanylate cyclase, which increases the levels of cyclic guanosine monophosphate (cGMP). Elevated cGMP levels lead to the relaxation of smooth muscle cells in the vascular system, resulting in vasodilation.

Side Effects

Common side effects of nitroglycerin include headache, dizziness, and hypotension. Severe side effects may include syncope, tachycardia, and methemoglobinemia.

Contraindications

Nitroglycerin should not be used in individuals with severe anemia, closed-angle glaucoma, or hypotension. It is also contraindicated in patients who are taking phosphodiesterase inhibitors such as sildenafil due to the risk of severe hypotension.

History

Nitroglycerin was first synthesized by Ascanio Sobrero in 1847. Its medical use was discovered by William Murrell in 1879, who found it effective in treating angina pectoris.

See Also

• Angina pectoris
• Heart failure
• Hypertension
• Myocardial infarction
• Raynaud's phenomenon