We all know that nitroglycerin is a life-saving drug for angina patients, however did you know that? Nitrates are also a violent explosive. Invented by the University of Turin chemist Sobrero in 1847, but because of its chemical instability, simply can not be used. 1866, the Swedish chemist Nobel solved the problem of the stability of nitroglycerin, after the German Defense Explosives Factory workers found that headache disease, with the time into the factory work, actually reduced day by day, which stumbled upon the role of nitrate-type smoke dust on the human body. First acquaintance with nitroglycerin Today, nitroglycerin has become the prevention and treatment of acute attacks of coronary heart disease, angina pectoris, the main drug. So, how did nitroglycerin get from the dynamite factory to the pharmaceutical factory? Legend has it that in the 19th century in England, there was a production of nitroglycerin explosives chemical plants have been a series of strange events: several workers usually strong as cattle weekend rest at home, sudden death occurred one after another, Scotland Yard immediately formed an investigation team into the factory to investigate, the results found that these workers have long suffered from coronary heart disease. But due to the usual inhalation of nitroglycerin dust particles, the result of the coronary vessels of the heart to expand, the myocardial blood supply and oxygen supply to increase, so usually failed to find that they have the disease. The cause of their death was instead the weekend rest at home, not timely inhalation of nitroglycerin dust particles and the onset of disease. This startling discovery immediately drew the attention of medical scholars. However, more than a hundred years later three American scientists, who won the 1998 Nobel Prize in Medicine, discovered the mechanism of action of nitroglycerin and other organic nitrates: the release of nitric oxide (NO), a substance that dilates vascular smooth muscle to make vasodilatation, thereby facilitating blood circulation and producing benefits for the cardiovascular system. As mentioned above, the fundamental mechanism of nitroglycerin is the release of NO, which activates guanylate cyclase (cGMP) in vascular smooth muscle cells and platelets, causing an increase in cGMP formation, resulting in vascular smooth muscle dilation and a decrease in blood pressure. Nitroglycerin mainly dilates veins, and its effect is dose-related in intensity. Peripheral venous dilatation causes blood to be trapped in the periphery, reducing return blood volume and decreasing left ventricular end-diastolic pressure (preload). Dilation of arteries results in a decrease in peripheral resistance (afterload). Arteriolar dilation results in a decrease in myocardial oxygen consumption, thereby relieving angina pectoris. Thus the vasodilating effect of nitroglycerin is now widely used for angina caused by coronary artery stenosis. Unique mode of administration: why sublingual? The capillaries under the tongue are very rich, and the oral mucosa absorbs the drug quickly, second only to the spray method, in addition to avoiding the first pass elimination effect of the liver. Sublingual medication body should be leaning on the seat in a sitting or semi-sitting position (to prevent postural hypotension), directly under the tongue or chewed tablets placed under the tongue, the drug can be quickly disintegrated or dissolved, through the sublingual mucosa absorption and play a fast-acting role, containing a slight burning sensation under the tongue, which is precisely the effective characteristics of the drug. If the mouth is dry, it can contain a little water, which is beneficial to the dissolution and absorption of drugs. It should be noted that you should not eat candy like only the drug in the mouth, because the tongue surface of the tongue moss and keratin layer is difficult to absorb drugs, while the rich venous plexus in the sublingual mucosa is conducive to rapid absorption of drugs. Generally speaking, sublingual nitroglycerin takes effect in 1 to 2 minutes and can last for 20 to 30 minutes. Why is there drug resistance? (1) Individual patients are sensitive to the drug, and some patients are not sensitive to nitrates and are prone to resistance. (2) Continuous use of nitroglycerin in high doses. (3) Long-term alcohol consumption or use of sedative-hypnotics increases the activity of hepatic drug-metabolizing enzymes, leading to drug resistance. (4) Taking nitroglycerin together with high doses of drugs that reduce vasodilation, such as analgesics and anti-inflammatory drugs What should I do if nitroglycerin is not effective? (1) Take the medication in small doses and intermittently, and do not drink alcohol during the medication period. (2) Change the type of nitroglycerin at the right time: for example, oral medication, spray medication, etc. (3) Combine with other drugs to reduce the adverse effects and improve the efficacy of the drug. (4) If the coronary artery stenosis is severe, blood flow reconstruction should be carried out, depending on the specific situation, interventional treatment or surgical coronary artery bypass surgery can be performed.