Is carvedilol also a rolol drug? What are its characteristics when used for hypertension?

A friend who suffers from high blood pressure told Huazi that the doctor prescribed him a blood pressure medication called carvedilol, which is also a type of lol drug. He asked Huazi, what is the difference between carvedilol and metoprolol and bisoprolol, and is it more effective?

Hua Zi said that although carvedilol does not contain "lol" in its name, it is also a lol drug and its mechanism of action is the same as other commonly used lol drugs. It mainly blocks β receptors, but also has a blocking effect on α receptors. Therefore, its effect is slightly stronger when treating hypertension.

1. Lolamine drugs without "Lolamine" in the drug name

Lolamine, a type of antihypertensive drug, is classified as a beta-blocker in pharmacology, but its formal name is difficult for ordinary people to remember, so it is simplified by using "Lolamine", which is included in most drug names. Carvedilol is a type of Lolamine drug that does not have "Lolamine" in its name.

Carvedilol blocks beta receptors, which can inhibit cardiac excitability, slow heart rate, reduce cardiac output, lower blood pressure and reduce cardiac oxygen consumption. Carvedilol can also block alpha receptors, which can directly dilate blood vessels and reduce vascular resistance, so it is slightly more effective when used to treat hypertension.

The blocking effect of carvedilol on β-receptors and α-receptors is approximately 10:1.

2. Carvedilol has no selectivity for β receptors

You may be curious, since carvedilol is more effective for hypertension, why is it not widely used? This is because beta blockers may cause adverse reactions when used. There are three subtypes of beta receptors: beta1, beta2, and beta3. The main beta receptor on the heart is the beta1 receptor, which is also the site of action of this type of drug.

That is to say, the more selective a drug is for β1 receptors, the better the efficacy, while the effect on other β receptors is associated with adverse reactions. For example, patients with respiratory diseases such as asthma and COPD, who mainly have β2 receptors in the bronchial tubes, can use drugs such as metoprolol and bisoprolol that are highly selective for β1 receptors, while carvedilol, which also has a strong blocking effect on β2 receptors, cannot be used.

3. Precautions when using carvedilol

Carvedilol inhibits β2 receptors, which reduces the breakdown of glycogen, increases insulin sensitivity, and causes a drop in blood sugar. Therefore, when taking the drug, diabetic patients need to measure their blood sugar and adjust their hypoglycemic medications. Carvedilol inhibits β1 receptors, which can mask the symptoms of palpitations and tremors during hypoglycemia, so more attention should be paid.

The dosage should be individualized, starting from the lowest dose and increasing slowly. If treating simple hypertension, the dose should be used to control the heart rate at 70-74 beats per minute; if combined with heart disease, the dose should be used to control the heart rate at 55-60 beats per minute, but do not exceed the maximum tolerated dose.

Carvedilol inhibits α receptors, causing vasodilation, which may cause postural hypotension. Therefore, it is recommended to take the drug with food to delay absorption and reduce the occurrence of postural hypotension. Within 4 hours of taking the drug, if you change from a lying or sitting position to an upright position, it is recommended to hold on to a fixed object and stand up slowly to avoid falling.

Like other beta-blockers, long-term use of carvedilol can increase the sensitivity of the heart's beta-1 receptors, and sudden discontinuation of the drug can cause a "drug withdrawal rebound" phenomenon, which can cause a sudden rise in blood pressure and induce angina pectoris. Therefore, if you need to stop taking the drug, you should use at least 2 weeks to slowly reduce the dosage.

To sum up, although carvedilol does not have "lol" in its name, it is also a lol drug. It has an inhibitory effect on both β receptors and α receptors, and is more effective as a blood pressure medication. However, it has low selectivity for β receptors and has more adverse reactions, so it is not as commonly used as metoprolol and bisoprolol. The drug must be used under the guidance of a doctor. If you have any questions about the use of the drug, consult a doctor or pharmacist. I am pharmacist Huazi, welcome to follow me and share more health knowledge.