Master Liu is 55 years old this year, suffering from hypertension for more than eight years and coronary heart disease for three years.
Last week, Master Liu ran out of metoprolol tablets that he had been taking, and he thought that nifedipine sustained-release tablets were still there, and he would go to the hospital to replenish the medicine together after eating. Unexpectedly, a few days after stopping the drug, he suddenly had chest pain at home, and then lost consciousness and fell to the ground. After being sent to the hospital, he was diagnosed with acute myocardial infarction, and Rao was unable to save his life after all-out rescue.
In this regard, the family found it difficult to accept, how could he have a heart attack when he had been well controlled? After learning about the past history, the doctor thought that Master Liu's sudden heart attack was related to his unauthorized discontinuation of metoprolol tablets, what was going on?
1. Long-term use of metoprolol may cause 5 major changes in the body
Metoprolol is a selective β1 receptor blocker, which works by blocking β1 receptors and inhibiting over-activated sympathetic activity, thereby slowing down heart rate, reducing myocardial oxygen consumption, inhibiting myocardial contractility, and increasing the ventricular fibrillation threshold by prolonging the effective refractory period of myocardium, thereby reducing the incidence of malignant arrhythmias. Clinically, it is mostly used to treat hypertension, angina, myocardial infarction, arrhythmia, heart failure and hyperthyroidism.
Although the application of metoprolol in cardiovascular diseases is very extensive, it is not suitable for everyone, and Hong Huaizhang, the pharmacist in charge of the Department of Pharmacy of the First People's Hospital of Huizhou City, reminded that people with sinus bradyarrhythmia/cardiogenic shock/obvious heart failure, people who are allergic to metoprolol and related components, patients with systolic blood pressure <100mmHg/patients with moderate to severe heart failure, heart rate less than 45 beats/minute or obvious first-degree heart block/second- and third-degree heart block, etc. are not suitable for taking the drug.
Zhang Fengying, a clinical pharmacist in the Department of Gastroenterology of Xinzheng Public People's Hospital in Henan Province, published an article reminding people who take metoprolol for a long time to pay attention to the following 5 major adverse reactions:
1. Drug discontinuation syndrome
Metoprolol will inhibit the heart's β1 receptors, resulting in an increase in the number of beta1 receptors and increased responsiveness, and sudden withdrawal of the drug will make it overreact to the catecholamine hormones produced by the body, which in turn will cause rebound phenomena such as increased blood pressure, tachycardia, and increased cardiac excitability.
2. Bradycardia
Patients who take long-term medication need to check their heart rate regularly to maintain the resting heart rate at 55~60 beats per minute, and consult a doctor in time once the heart rate is found to be < 45 beats per minute.
3. Headache/dizziness
Metoprolol is a fat-soluble drug, which easily penetrates the blood-brain barrier and enters the central nervous system, increasing the incidence of dizziness and headache.
4. Abnormal blood glucose/dyslipidemia
Long-term use of drugs may cause blood sugar and dyslipidemia, especially for people with diabetes and hyperlipidemia, especially those who need to pay attention to these two indicators.
5. Male sexual dysfunction
Some men experience sexual dysfunction after taking the drug because the drug affects sympathetic activity.
2. Metoprolol eats every day, and these 4 things must be kept in mind
For patients who are taking metoprolol, it is important to pay attention to these things in daily life to avoid unnecessary effects on health due to improper medication.
1. Don't stop the drug suddenly
Abrupt discontinuation of the drug in long-term patients may lead to unstable angina, myocardial infarction, and sudden death, and the dose should be gradually reduced for at least 2 weeks. The dose is halved until it reaches 25 mg or 23.75 mg, and the final phase of discontinuation is maintained for at least 4 days. In addition, patients with high blood pressure cannot directly stop taking metoprolol.
2. Take medication on an empty stomach
Liu Zhijun, deputy chief pharmacist of Beijing Hospital, reminded in an article: It is generally recommended to take metoprolol on an empty stomach, because it is a fat-soluble drug, and taking oily foods will promote the absorption of the drug. Most of the time, patients cannot guarantee that the food they eat at each meal is the same, so if they take it after meals, it is easy to absorb the drug differently each time, which can easily affect heart rate and blood pressure. The absorption rate of taking the drug on an empty stomach is about 40%, which can ensure that the concentration of the drug is constant in the body, which is good for disease control.
3. Start with a small dose
It is recommended to start with a small dose for the first dose, generally 25mg once in the morning and evening, and gradually increase to 50mg and 100mg each time. It should be noted that not all patients need to increase to 100 mg/dose, and the specific dose depends on the patient's heart rate.
4. Inform the doctor before surgery
For patients who need surgery, it is necessary to inform the doctor in advance that they are taking metoprolol, and if the drug is stopped before surgery, it should be at least 48 hours in advance, and the specific situation should be adjusted according to the individual.
3. Metoprolol is taken with 6 drugs, which is easy to bring risks
In addition, it should be noted that patients taking metoprolol also need to be aware of adverse reactions between drugs, and it is not recommended to take them with these drugs.
1. Barbiturates
Common phenobarbital, isoambarbital, etc., the effect of this kind of drug is sedation, hypnosis, anticonvulsant, and the combination of metoprolol will lead to enhanced metabolism of metoprolol, weakened drug efficacy, and affect the effect of treatment.
2. Propafenone
Propafenone is used for the treatment of paroxysmal tachycardia and supraventricular tachycardia, and the combination of metoprolol will increase the blood concentration of the drug by 2~5 times, which is easy to cause drug toxicity and side effects. And propafenone also has a certain β receptor blocking effect, and it is difficult to control the dose when combined with metoprolol, and the drug concentration may be too large and poisoning may occur after taking it.
3. Verapamil
Verapamil is a calcium-channel blocker, mostly used for the treatment of angina, and the combination with metoprolol can easily cause bradycardia and blood pressure drop.
4. Amiodarone
Amiodarone is a class III antiarrhythmic drug used to treat paroxysmal tachycardia and prevent ventricular fibrillation, and may cause significant sinus bradycardia when combined with metoprolol.
5. Non-steroidal anti-inflammatory/antirheumatic drugs
Representative drugs include aspirin, indomethacin, ibuprofen, etc., and the combination with metoprolol will counteract the antihypertensive effect of β receptor blockers.
6. Antidepressants
Metoprolol is mainly metabolized by the liver enzyme CYP2D6, and commonly used antidepressant drugs can inhibit liver enzyme activity, delay the metabolism of metoprolol, and reduce blood concentration.
For ordinary people, it is difficult to remember so many drug contraindications, we only need to do not add drugs at will during the period of taking the medicine, and the doctor can inform the drug we are taking when prescribing the drug, so that we can also avoid the risk to a large extent.
Resources:
[1] "Taking Metoprolol, these 6 major problems must be known!" 》. Science Park 2024-03-21
[2] "Metoprolol that lowers heart rate and blood pressure has a high absorption rate after eating, but pharmacists recommend eating on an empty stomach!" Also pay attention to these points! 》. Medical Microvision 2024-02-06
[3] "Metoprolol should be taken with the following drugs, drug interactions may occur". Lingnan Journal of Cardiovascular Diseases 2020-05-06
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