Nitroglycerin can be said to be a well-known "life-saving medicine", which is an emergency medicine used to alleviate acute attacks of angina. Some people say that nitroglycerin is spicy when taken sublingually, while others report it as sweet? Be careful, changes in taste may indicate that the medication has become ineffective. Today, the pharmacist will talk to you about the correct usage, storage techniques, and precautions of nitroglycerin. Why do you have to sit while taking this medicine? During an acute attack of angina, please sit in a chair or semi recline position with a nitroglycerin tablet under your tongue. Usually, it takes 2-3 minutes to take effect. If the pain does not subside after 5 minutes, you can take one tablet under the tongue again. If you feel dry mouth, you can take a small sip of water first and then place the tablet under the tongue, which can help dissolve the medication. Within 15 minutes, one tablet of nitroglycerin can be reused every 5 minutes. If the pain persists after taking three tablets, please seek medical attention immediately. Why does this medicine need to be taken sublingually? Simply put, it is most conducive to the effectiveness of the drug. Oral administration, due to the significant first pass clearance effect of the liver, has a bioavailability of less than 10%. And sublingual administration absorbs quickly and completely, taking effect in 2-3 minutes and reaching maximum effect in 5 minutes. It does not undergo first pass clearance by the liver, and its bioavailability can reach 80%. Why do we need to sit and take medication? When lying flat, due to an increase in cardiac blood flow, it can increase the preload of the heart, increase myocardial oxygen consumption, and worsen angina. Therefore, medication should not be used when lying flat. When standing, due to the vasodilator effect of nitroglycerin, it can cause insufficient blood supply to the cerebral vessels and lead to dizziness, so medication should not be used while standing. The validity period of unopened nitroglycerin tablets after opening is up to three months. Please store them in a dark, sealed, and cool place (not exceeding 20 ℃) according to the instructions. The expiration date can be found on the packaging box of the medicine bottle. Please keep the opened nitroglycerin tablets in the original packaging bottle and avoid placing them in close clothing pockets. Body temperature may accelerate the decomposition of nitroglycerin, leading to reduced efficacy or ineffectiveness. You can place them in your handbag or outer pocket. In addition, the degree of sealing is also related to the therapeutic effect of nitroglycerin. Improper sealing and repeated bottle opening can cause a decrease in nitroglycerin content. Please tighten the bottle cap after each use and avoid placing other medications in the medicine bottle. Due to the susceptibility of nitroglycerin to environmental factors, it should not be stored for more than 3 months after opening. Eating this taste indicates that the efficacy has been lost. After taking nitroglycerin under the tongue, there may be a slight burning, stinging, or spicy sensation, which is normal. If there is no spiciness or only sweetness, it indicates that nitroglycerin may be ineffective. It is recommended that you replace it immediately. The correct usage and storage methods are essential for drugs to achieve their desired therapeutic effects and prevent more serious cardiovascular adverse events. Please read and remember them carefully. (Le Xin She) Wen/Zhao Ting (Beijing Stomatological Hospital)