Depending on the type of heart disease, doctors will choose appropriate drugs for treatment, such as nitrates, calcium channel blockers (CCB), diuretics, beta-blockers, etc. wait. This article will focus on the beta blockers and introduce their mechanism of action and applicable situations.

The mechanism of action of beta-blockers

Beta-blockers, also known as beta-adrenergic blockers or beta-sympathetic nerve blockers, prevent norepinephrine (Norepinephrine, also known as norepinephrine) and epinephrine (Epinephrine) from interacting with the nerves. Drugs that bind to beta receptors. Norepinephrine and epinephrine are neurotransmitters that can transmit messages between nerves through the blood.

Beta receptors in the human body can be divided into three main categories:

β 1 receptors: located in the heart, kidneys, and eyes

β 2 receptors: located in the lungs, gastrointestinal tract, liver, uterus, skeletal muscles and blood vessels

β 3 receptors: located in fat cells

The protagonist of this article, beta-blockers, mainly block the effects of epinephrine by blocking β1 and β2 receptors, slowing the heart rate, dilating blood vessels, and lowering blood pressure.

Uses of beta blockers

It can be mainly taken orally or intravenously to treat heart diseases and related symptoms, including angina, hypertension, arrhythmia, heart failure, etc. For patients who have had a heart attack, beta-blockers can also prevent recurrence of myocardial infarction.

In addition, beta-blockers can also be used to treat hyperthyroidism, Long QT syndrome, akathisia, panic disorder, glaucoma, and migraine. with some aggressive behavior.

It should be noted that for patients with both heart disease and lung disease (such as asthma), beta2 receptor antagonism may cause bronchoconstriction, which will increase the risk. Therefore, the feasible method should be to “Selective beta-blockers” are used for treatment. Please see the following introduction to the types of beta-blockers.

Types of beta blockers

Although their main function is to prevent beta receptors from contacting epinephrine, beta blockers can actually be subdivided into the following types based on the type of receptor:

1. First generation—non-selective beta-blockers: block β1 and β2 receptors, affecting the heart, blood vessels, and trachea. Related drugs such as Propranolol, Nadolol, etc.
   
2. Second generation—selective beta-blockers: mainly act on β1 receptors and therefore have less impact on the lungs. Related drugs such as Metoprolol, Atenolol, Bisoprolol, etc.
   
3. Third generation – beta blockers (with additional vasodilator effect): In addition to acting on Beta receptors, these blockers also antagonize α1 receptors, causing vasodilation and lowering blood pressure and heart rate. Effect. Related drugs such as Carvedilol, Nebivolol, Labetalol, etc.

The first and second generation beta-blockers have many side effects, so they are usually not used as first-line drugs. However, new-generation beta-blockers like Carvedilol and Nebivolol can effectively reduce the risk of The ejection fraction of the heart, which is the amount of blood that the heart can send out with each contraction, plays a role in the treatment of high blood pressure in patients with heart failure or coronary heart disease.

Beta blocker side effects

1. Diarrhea
   
2. Stomach cramps
   
3. Muscle spasms
   
4. Feel sick and vomit
   
5. Tired
   
6. Rash
   
7. Hair loss
   
8. Weak
   
9. Insomnia
   
10. Lose sense of direction
    
11. Tired
    
12. Weight gain
    
13. Dizziness
    
14. Cold fingers or toes

In most cases, patients will not experience serious side effects after taking beta-blockers, but if you experience the following symptoms after taking the medication, please seek medical assistance as soon as possible.

1. Heart problems: Difficulty breathing and coughing (especially after exercise), edema in ankles and legs, angina (chest pain), irregular heartbeat.
   
2. Lung problems: difficulty breathing, wheezing, chest pressure.
   
3. Liver problems: yellowing of skin and whites of eyes

Precautions for beta blockers

You should discuss this with your doctor before using or stopping any medication. Arbitrary discontinuation of beta-blockers may result in worsening of angina, myocardial infarction, severe arrhythmia, or even sudden death. The following is a list of drugs that may affect beta-blockers, as well as medication groups that require special attention: (Recommended reading: It only takes a few minutes to kill! Do this to prevent sudden cardiac death)

1. Taking different drugs at the same time may affect each other, affect the effect of treatment, and even cause danger. If you take the following medications, please inform your doctor:
   
   • Nonsteroidal anti-inflammatory pain relievers (NSAIDs): such as ibuprofen
     
   • Allergy drugs: such as norepinephrine, epinephrine
     
   • Diabetes medications: such as insulin
     
   • COPD drugs
     
   • Asthma medication
     
   • Other blood pressure-lowering drugs: such as nitrates, Tamsulosin
     
   • Parkinson’s disease drugs: such as Levodopa
     
   • Arrhythmia drugs: such as Amiodarone, Flecainide
     
2. Your doctor may not consider beta-blockers for treatment if you have any of the following conditions:
   
   • Chronic obstructive pulmonary disease (COPD)
     
   • hypotension
     
   • slow heartbeat
     
   • Severe blood circulation problems in the extremities (Raynaud phenomenon)
     
   • metabolic acidosis
     
   • asthma
     
   • Preparing for pregnancy or being pregnant
     
   • breast-feeding

List of beta-blocker drugs

Listed below are the drug names of each component of beta-blockers. Please note that the ingredient name is not the same as the “drug name”. For more information,

• Acebutolol
  
• Atenolol
  
• Betaxolol
  
• Bisoprolol fumarate
  
• Carteolol
  
• Carvedilol
  
• Esmolol
  
• Labetalol
  
• Metoprolol
  
• Nadolol
  
• Nebivolol
  
• Penbutolol
  
• Pindolo
  
• Propranolol
  
• Sotalol
  
• Timolol

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