Today, let’s talk about the ins and outs of nitroglycerin, usage and dosage, preparation methods and precautions.
Nitroglycerin was very noticeable when it was first invented. Nitroglycerin is also a type of glycerin, not a drug, but an explosive. Just as warfarin is not an anticoagulant but a rat drug, Viagra is not a cure at first… but it is also true for coronary heart disease.
Ins and outs: Listen to a little story first
During the war, many arsenal workers produced explosives, nitroglycerin, which produced nitroglycerin in the arsenal from Monday to Friday. When I go home with my wife and children on the weekend, I will commit a heart attack, so I won’t worry about it. Going back to work on Monday, the heart disease disappeared miraculously! A person can interpret this as an accident. One can explain this as an accident. But many people do this many times. This is certainly not accidental but inevitable.
Later, studies have found that nitroglycerin has the effect of dilating coronary vessels, which can alleviate the coronary vessels of the stenosis and sputum and improve myocardial circulation. So, opportunities are always reserved for insightful and thoughtful people.
Foreigners still pay more attention to the mechanism of drug action, but they must know why. Further studies have found that nitroglycerin can be decomposed into NO (nitrogen monoxide) in the body, similar to endothelium, is a messenger widely present in the body, can act on vascular smooth muscle cell surface receptors, activate guanylate cyclization Enzyme, which is an increase in guanosine monophosphate (cGMP) in smooth muscle and other tissues, leads to dephosphorylation of myosin light chain, regulates the contraction of smooth muscle, causes vasodilation, relaxes smooth muscle cells, and causes vasodilation and thickening. Reducing the blood volume, reducing the load on the heart before and after, thereby exerting its pharmacological effects, which leads to another characteristic of nitroglycerin: it dilates the arteriovenous vascular bed, mainly to dilate the vein, and its intensity is dose-dependent.
In fact, I am also very fond of the root of the question, the general emergence of new drugs or rare drugs, the first thing I am most interested in is actually the mechanism of action of drugs, to see what kind of drugs it belongs to, or a new category of drugs. See how it produces physiological effects and how it is metabolized. Then look at the indications and contraindications, and finally use the mechanism of action of the drug to reverse its indications and contraindications, and finally establish an effective data link, and the least concerned is – drug usage and dosage!
Anyway, it can not be over-dosed, the medication assistant wrote clearly, it is quite authoritative, and then according to the mechanism of action of the drug to determine whether this drug is used, how to adjust the dosage of the drug.
Do you like to push it back, or vice versa?
Usage and dosage of nitroglycerin
If nitroglycerin is intravenously or intravenously pumped, it will work very fast in the body and will take effect in less than 1 minute.
Our nitroglycerin injections are all 5 mg. Have you heard of other specifications? Anyway, I have not heard of it. Nitroglycerin almost did not indicate the kg body weight on all medication instructions. Everyone noticed that it was given: X ml/min. It is because nitroglycerin is very individualized, and the range of dosage is very wide. The difference in kilograms of body weight (most people are concentrated between 50 kg and 80 kg) is almost negligible in such a wide range of medications. !
The patient has heart failure! I am so upset, I am sweating, sweating! Blood pressure has soared! Immediately come up with a pump of nitroglycerin, it can also play the role of “one into the soul.”
The usual dose of nitroglycerin is: 5 ug/min. The initial dose is pumped in. The dose is adjusted according to the blood pressure every 3-5 minutes, which can increase the pump speed by 5 ug. If the effect is not ideal after 20 ug, it will double. For example, 10 ug plus, it is said that there is an example added to 200 ug / min, you can not really widen the dose!
What is the most important criterion for adjusting the drug dose? It is blood pressure! (Knocking on the blackboard!), so blood pressure must be accurate and timely. This is why the recommended blood pressure monitoring is recommended so that you can see the blood pressure at any time without significantly increasing the workload of the nurse’s sister. Remember that any operation at a cost is costly.
Method for preparing nitroglycerin
Then the problem is coming again. How do you match this medicine? very messy! Let’s take a review of the preparation method below.
Although I said above, first of all, the dose of 5 ug / min is relatively small, it is certainly not the dose used normally, it will be much larger than this dose.
We took 20 ug for the normal application dose. If a 50 ml pump is used, it is 20 ug*60 min = 1200 ug = 1.2 mg, which means that 1.2 mg is pumped per hour. If the speed is 5 ml, the 50 ml liquid can be pumped 10 The hour is 1.2 mg*10 = 12 mg. Good calculation?
First take two and a half less nitroglycerin in the syringe and then pump the solvent to 50 ml! Some people also have to calculate the amount of solution in the drug itself, which is not necessary at all. Before you start, you will go at a speed of 1 ml. Look at the blood pressure every three minutes, then add 1 ml. You can add it to the normal dose in about ten minutes. If it is not enough or the blood pressure is not up to standard, the symptoms have not improved. , then add 2 ml each time.
(Try to learn to adjust the pump yourself, don’t expect to expect the nurse sister, the art does not press, I don’t expect anyone to count on myself, I am now playing the trocar, not to mention the ordinary venous needle, what blood? It’s even more important to take blood tests.)
If there is no nitroglycerin pump? Or is the pump broken or the pump used for others? Then nitroglycerin intravenously! How to match?
Still calculated at a speed of 20ug/min, we intend to drop 20 drops/min. Then 20ug = 20 drops = 1 ml. Do you understand? How much should you add in 250 ml of water? 20ug*250 ml = 5000ug = 5 mg = 1 nitroglycerin. Simple?
Nitroglycerin is a good medicine, but it should also be avoided to fall into the pit. As the saying goes, it is a drug three-point poison, and nitroglycerin can not be exempted from customs. Then, count the pits one by one, pay attention (and knock the blackboard again!) , fall in and no one pulls you!
1. Nitroglycerin is not the higher the amount, the better, enough. Just use the minimum dose that it works, don’t mess up. Didn’t the beginning of the stack be superimposed one by one? As long as you reach the target at a certain dose, you can maintain this dose and don’t add it. For example, the clinical symptoms are obviously relieved, the blood pressure drops to the target value, etc. These are the signals to stop the increase.
2. Nitroglycerin should be avoided as far as possible for patients with insufficient blood volume or low systolic blood pressure. Is this well understood? Look at the pharmacological mechanism that I said earlier! It is expanding capacity and lowering blood pressure. If you don’t expand the capacity, it will be insufficient. If you expand it, don’t you kill it?
3. Long-term continuous use of nitroglycerin is prone to tolerance. In fact, all pharmacological effects based on receptor ligands will be more or less tolerant, which is the role of receptor up- or down-regulation. In order to avoid this phenomenon, try to use intermittently and delay the tolerance. The empty window period of 5-6 hours per day will obviously delay the occurrence of tolerance.
4. Because of angina caused by hypertrophic obstructive cardiomyopathy, nitroglycerin is ineffective or even harmful, so pay close attention. Do not think that as long as angina, nitroglycerin, this is not a panacea.
5. Excessive dose can over-expand the blood vessels in the brain, causing headaches, even very intense.
6. This drug, like sodium nitroprusside, acts as a pharmacological agent by releasing NO. It is also as light as sodium nitroprusside. Although it is not sensitive to light like sodium nitroprusside, it should be avoided as much as possible. Some plastic infusion sets can absorb nitroglycerin and should be avoided.
7. When combined with sildenafil, it can act as a superposition, resulting in overdose, sildenafil = Viagra, the blue Xiaoyao pill.
