What are Beta Blockers?

Beta-blockers are used to treat several conditions, usually by regulating heart activity.

Also called beta-adrenoreceptor blocking agents, these medications bind to beta receptors present on the cells of the heart, arteries, kidneys and other tissues that are stimulated by the stress hormones (e.g. adrenaline and noradrenaline).

Beta blockers are often used to treat high blood pressure, angina, heart attack and atrial fibrillation. Less common indications include migraine, tremor and anxiety.

Examples of drugs in this class include acebutolol, atenolol, bisoprolol, carvedilol, celiprolol, labetalol, metoprolol, nadolol, nebivolol, oxprenolol, pindolol and timolol.

Mechanism of action

The sympathetic nervous system is part of the autonomic nervous system that controls various vital functions of the body including heart rate and blood pressure.

The two main beta receptors that are targeted by beta blockers are the beta 1 receptor and the beta 2 receptor. A large number of beta 1 receptors are present on the heart and kidney cells, while the beta 2 receptor is the predominant regulator of vascular and nonvascular smooth muscles.

Some beta blockers are selective and block the beta 1 receptor more than the beta 2 receptor. These are called cardioselective agents. Nonselective beta blockers are those that bind to both types of receptors.

Some of the effects of using beta blockers to block these receptors include:

Effects on the kidney - Blocking of the beta 1 receptors on the kidneys prevents the release of renin from juxta-glomerular cells. This suppresses the renin-angiotensin-aldosterone system, helping to regulate blood pressure as well as fluid and electrolyte balance.

Effects on the heart - Beta 1 receptors are present on the sino-atrial node, which is responsible for generating the impulses that make the heart beat. Blocking the sino-atrial node therefore reduces heart rate.

Uses of beta blockers

Some examples of the conditions beta blockers are used to treat include high blood pressure, angina, heart failure, cardiac arrhythmias and atrial fibrillation, anxiety, severely overactive thyroid (thyrotoxicosis), glaucoma and migraine.

Pharmacological Properties

Beta blockers can be taken in the form of capsules, a solution, eye drops or by injection and are usually eliminated from the body via the liver or kidney.

Beta blockers that are soluble in fats such as labetalol, metoprolol, pindolol and propranolol are excreted by the liver, while those that are soluble in water such as atenolol are cleared by the kidney. Fat soluble drugs have a short duration of action, while water soluble drugs have a longer duration of action.

Side effects

Some of the side effects of beta blockers are more common than others.

Some examples of more common side effects are given below:

  • Dizziness
  • Fatigue
  • Cold extremities (hands and feet)
  • Slow heartbeat
  • Blurred vision
  • Diarrhea and nausea

Some examples of the less common side effects include:

  • Insomnia
  • Loss of libido
  • Depression

Further Reading

Last Updated: Jun 17, 2023

Dr. Ananya Mandal

Written by

Dr. Ananya Mandal

Dr. Ananya Mandal is a doctor by profession, lecturer by vocation and a medical writer by passion. She specialized in Clinical Pharmacology after her bachelor's (MBBS). For her, health communication is not just writing complicated reviews for professionals but making medical knowledge understandable and available to the general public as well.

Citations

Please use one of the following formats to cite this article in your essay, paper or report:

  • APA

    Mandal, Ananya. (2023, June 17). What are Beta Blockers?. News-Medical. Retrieved on December 08, 2024 from https://www.news-medical.net/health/What-are-Beta-Blockers.aspx.

  • MLA

    Mandal, Ananya. "What are Beta Blockers?". News-Medical. 08 December 2024. <https://www.news-medical.net/health/What-are-Beta-Blockers.aspx>.

  • Chicago

    Mandal, Ananya. "What are Beta Blockers?". News-Medical. https://www.news-medical.net/health/What-are-Beta-Blockers.aspx. (accessed December 08, 2024).

  • Harvard

    Mandal, Ananya. 2023. What are Beta Blockers?. News-Medical, viewed 08 December 2024, https://www.news-medical.net/health/What-are-Beta-Blockers.aspx.

Comments

The opinions expressed here are the views of the writer and do not necessarily reflect the views and opinions of News Medical.
Post a new comment
Post

While we only use edited and approved content for Azthena answers, it may on occasions provide incorrect responses. Please confirm any data provided with the related suppliers or authors. We do not provide medical advice, if you search for medical information you must always consult a medical professional before acting on any information provided.

Your questions, but not your email details will be shared with OpenAI and retained for 30 days in accordance with their privacy principles.

Please do not ask questions that use sensitive or confidential information.

Read the full Terms & Conditions.