Glyceryl trinitrate (pharmacology)

Nitroglycerin.svg

Glyceryl trinitrate (GTN), also known as nitroglycerin and trinitroglycerin, is a medication used to treat and prevent chest pain related to coronary artery disease and heart failure. It is also used in the management of acute myocardial infarction and during cardiac surgery to decrease heart workload and oxygen demand.

Medical uses

GTN is effective in relieving chest pain associated with angina pectoris. It is administered in several forms, including sublingual tablets, sprays, and patches. The drug works by releasing nitric oxide (NO), which helps to dilate the blood vessels, thereby improving blood flow and reducing heart strain.

Mechanism of action

The primary mechanism of action of glyceryl trinitrate is through the donation of nitric oxide which activates the enzyme guanylate cyclase in vascular smooth muscle cells. This leads to an increase in cyclic guanosine monophosphate (cGMP), resulting in smooth muscle relaxation and vasodilation.

Pharmacokinetics

GTN has a rapid onset of action, especially when administered sublingually or via spray. The drug is metabolized primarily by the liver, and its effects are short-lived due to rapid inactivation.

Adverse effects

Common side effects include headaches, dizziness, and a rapid heartbeat. Orthostatic hypotension (sudden blood pressure drop upon standing) may also occur. Long-term use can lead to tolerance, necessitating higher doses to achieve the same effect.

History

Glyceryl trinitrate was first synthesized in 1847 by Italian chemist Ascanio Sobrero. Its use in medicine began in the 1860s when it was discovered to alleviate chest pain associated with angina.

Society and culture

GTN is listed on the World Health Organization's List of Essential Medicines, indicating its importance in a basic health system.