How Do Selective Beta-1-Blockers Work?

Selective beta-1 blockers are a subclass of beta-blockers that are commonly used to treat high blood pressure.

Beta-1 receptors are mainly found in the cardiac tissues and kidneys. Selective beta-1-blockers bind to the beta-1 receptor sites and inhibit the action of hormones norepinephrine and epinephrine. Norepinephrine and epinephrine are the hormones that are produced by the adrenal gland and also by the nerve cells and are released inside the circulatory system when a person is emotionally stressed.  

Beta-1 receptors upon activation, increase the intracellular calcium concentration in heart muscles, leading to increased heart muscle contractions and heart rate. The enzyme renin is released into the circulation by the kidneys when the smooth muscles are activated and this triggers the production of sodium and water regulatory hormones, angiotensin II and aldosterone. These hormones cause retention of sodium and water and increase blood pressure.

In addition to high blood pressure, selective beta-1 blockers are used in conditions such as:

• Cardiac arrhythmias (improper beating of the heart, whether irregular, too fast or too slow.)
• Heart failure (heart fails to pump enough blood to the body)
• Coronary artery disease
• Stable angina (chest pain due to poor blood flow)
• Decreased left ventricular function post-myocardial infarction (heart attack)
• Migraine prophylaxis
• Tremors
• Anxiety disorder

Common side effects of selective beta-1 blockers include:

• Nausea and vomiting
• Diarrhea
• Rash
• Fatigue
• Dry mouth and eyes
• Hyperglycemia (high blood sugar)
• Hypoglycemia (low blood sugar)
• Dizziness
• Shortness of breath
• Depression
• Headache
• Blurring of vision
• Sexual dysfunction
• Serious side effects may include:
• Bradycardia (low heart rate)
• Hypotension (low blood pressure)
• Chest pain
• Heart failure (heart fails to pump enough blood to the body)
• Heart block (heartbeats slowly, which results in the electrical signals being partially or totally blocked)

The information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with your doctor or pharmacist to make sure these drugs do not cause any harm when you take them along with other medicines. Never stop taking your medication and never change your dose or frequency without consulting your doctor.

Drug names include:

• Atenolol
• Betaxolol
• Bisoprolol
• Brevibloc
• Bystolic
• Byvalson
• Celiprolol
• Edsivo
• Esmolol
• Kapspargo Sprinkle
• Kerlone (DSC)
• Lopressor
• Metoprolol
• Monocor
• Nebivolol
• Nebivolol/valsartan
• Tenormin
• Toprol XL
• Zebeta