The first outpatient clinic in the Year of the Tiger, a middle-aged female patient with hypertension.
Patient: Doctor, I would like to change the controlled-release nifedipine tablets I am eating now to amlodipine.
Doctor: Why?
Patient: People say that this medicine is better, I want to try it.
Doctor: It is not recommended that you change your dressing now.
Why?
Now that the blood pressure of the drug is normal and stable, there is no need to change the drug that is generally effective in reducing blood pressure, has a stable effect, and has no obvious side effects.
During the dressing change, the concentration of the drug needs to accumulate, which can easily cause blood pressure fluctuations during this process.
It is now winter, winter is the season when blood pressure is easy to rise and unstable, and changing drugs is not conducive to controlling blood pressure.
To say the first one, we do not recommend that patients change their dressing, but it is not impossible for patients to change their dressing. Mainly due to the characteristics of these two drugs, due to the current winter, the dressing change is not appropriate.
Let's talk about the characteristics of nifedipine controlled-release tablets and amlodipine.
Both drugs fall under the category of "calcium antagonists", also known as "calcium channel blockers". The effect is to reduce blood pressure by blocking the calcium channel on the smooth muscle cells of the blood vessel wall, inhibiting the contraction of smooth muscle cells, making the blood vessels easily expand. Both drugs are considered long-acting preparations, but the specific way of playing a long-acting role is different.
Nifedipine controlled-release tablets use controlled-release technology to "change" the short-acting drug of nifedipine into a long-acting drug.
Specifically, the short-acting nifedipine is put into a shell with many small holes in the laser to control the speed of drug release. When the tablet reaches the gastrointestinal tract, the drug in the shell is slowly released and absorbed by the human body. Because the number of drugs released by the small holes has a fixed number, the speed of drug release is very uniform, which lengthens the action time of short-acting drugs. In this way, the antihypertensive time is longer, the effect is not so violent, the short-acting drug plays a long-acting role, and the side effects are alleviated.
However, this medicine shell cannot be destroyed. Therefore, the pills cannot be divided and crushed. "Eat a pill, pull out a shell" is a true portrayal of taking this medicine.
The advantage of nifedipine controlled-release tablets is that they can play a hypotensive effect when eaten, and there is no accumulation in the body after stopping the drug.
What about amlodipine? Amlodipine itself is a long-acting drug because of its long half-life.
The drug works in the body and needs to reach a certain amount. Drug metabolism has a characteristic, that is, after the drug is used, the drug reaches a stable concentration in the blood, and it takes 5 to 7 "half-life" time. In this way, drugs with a long half-life take longer to reach homeostasis. Therefore, the advantage of long-acting drugs is long-acting, and it can be used once a day, and the bad aspect is that the effect is slow.
The half-life of amlodipine is generally 30 hours or more, and can grow to 90 hours in the elderly. In this way, the accumulation of drugs in the body is relatively slow, and the antihypertensive effect is slowly obvious. Therefore, when starting to take drugs, it takes about a week to gradually become obvious, and the effect is stronger from half a month to a month. Therefore, some people will feel that their blood pressure is getting lower and lower as the time is prolonged after taking the drug. Such an advantage is that the antihypertensive time is long, the effect is stable, and even sometimes "missing" 1 time is not a big problem; it can also be crushed and broken; especially for patients with heart failure who have no negative effect on cardiac function and heart failure can also be used.
Therefore, it is possible for patients to replace nifedipine controlled-release tablets with amlodipine itself.
However, due to the characteristics of these two drugs, there will be a problem in the process of changing the drug, and the efficacy of the drug may not be connected. Therefore, some patients with high blood pressure and instability also need to overlap the two drugs for a short time during the process of changing drugs.
Now it is another cold winter, and the blood pressure itself is unstable, and it is easy to be stimulated by the cold. At this time, the change of medicine, blood pressure fluctuations will be greater, which is not conducive to controlling blood pressure.
Moreover, the patient now uses the drug to control blood pressure stably, there is no adverse reaction, and there is no rush to change the drug.
Therefore, patients are discouraged from changing drugs temporarily, and then consider changing drugs when their blood pressure is relatively stable and reduced in the summer.
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