Nitroglycerin (drug)

Nitroglycerin (also known as glyceryl trinitrate or GTN) is a pharmacological agent used primarily in the treatment of angina pectoris and heart failure. It is a potent vasodilator, which means it expands blood vessels, allowing blood to flow more easily.

History

Nitroglycerin was first synthesized by Italian chemist Ascanio Sobrero in 1847. However, its medicinal use was not discovered until 1867, when British physician William Murrell began using it to treat angina pectoris.

Pharmacology

Nitroglycerin belongs to a group of drugs known as nitrates. It works by relaxing the smooth muscle in the walls of blood vessels, particularly veins. This reduces the amount of blood returning to the heart, which decreases the heart's workload and oxygen demand. This mechanism of action is particularly beneficial in conditions like angina, where the heart's oxygen demand exceeds its supply.

Clinical Use

Nitroglycerin is used in the management of several cardiovascular conditions. These include:

• Angina pectoris: Nitroglycerin is a first-line treatment for angina. It can be used to relieve acute episodes or to prevent anticipated attacks.
• Heart failure: Nitroglycerin, often in combination with other drugs, can be used to manage acute and chronic heart failure.
• Myocardial infarction: Nitroglycerin is sometimes used in the early management of myocardial infarction (heart attack) to reduce heart workload and limit the size of the infarct.

Side Effects

Common side effects of nitroglycerin include headache, dizziness, and hypotension. In rare cases, it can cause severe hypotension or reflex tachycardia, a rapid heart rate in response to low blood pressure.

Contraindications

Nitroglycerin should not be used in patients with certain conditions, including severe anemia, hypotension, and certain types of cardiomyopathy. It should also not be used in patients who are taking phosphodiesterase type 5 inhibitors, such as sildenafil (Viagra), due to the risk of severe hypotension.

See Also

• Nitrates
• Angina pectoris
• Heart failure
• Myocardial infarction