What is a Beta Blocker and How Does It Work?

Our sense of touch is made possible by nerve endings referred to as neurotransmitters.  This makes possible the sending of signal from the skin to the brain, which the brain then interprets.  On some of these nerve endings, chemicals like noradrenaline are released when the nerve is stimulated.  In turn, this chemical puts beta-adrenergic receptors on alert.  These receptors are found all over the body, with some more sensitive than the others.  When these receptors are located in critical organs like the heart, the brain and blood vessels, slight stimulation can lead to serious consequences.

Beta receptors are further categorized into β1 receptors that are located in the heart, eyes, and kidneys; β2 receptors that are found in the lungs, gastrointestinal tract, liver, uterus, blood vessels, and skeletal muscles; and β3 receptors that hide inside fat cells.

Additionally, beta receptors are stimulated by adrenaline, a hormone pumped by the adrenal glands when stressors are present, as in the case of fight-or-flight.  This then creates a cascade of events in the body that, when occurring repeatedly, can strain the heart, depress the immune system and result to just about anything unpleasant and unhealthy.

Knowing how the beta receptors work makes it easier to understand how beta blockers work.  Quite simply, beta blockers are a group of medicines that slow down, if not “block”, the effects of stimuli on beta receptors.  In other words, beta blockers prevent the transmission of nerve impulses.

If a stimulus jumpstarts the adrenal glands, the result is stress.  Stress, in this context, is not just the kind that we feel when we stew in traffic or have a deadline to beat.  Stress means causing the organs to overwork. This could be fatal when that organ is the heart.

Among people who are easily excitable or get agitated by stressors, the heart beats faster and harder, causing the blood vessels to constrict.  This, in turn, results to high blood pressure or, in cases where arteries are plugged up by fats, heart attack.

It is easy to see how beta-blockers can be lifesavers in this respect:  they suppress the impulses of the body to quickly react to stressors, thus slowing down pulse rate and reducing the cardiovascular workload.  In fact, research studies have shown that beta-blockers alleviate symptoms of angina pectoris, improve the chances of survival of patients who have had heart attacks, and treat erratic heartbeats (especially tachychardia, where the heart beasts faster than normal).

The beta blockers in the market today block β1 and β2 receptors – which has huge implications.  This means that any stimulation in the areas where β1 and β2 reside can be slowed down in order to minimize, if not altogether eliminate, severe consequences.

This must be the reason why beta blockers are no longer just confined in the cardiovascular department.  Beta blockers are increasingly used to treat people with glaucoma, a condition of the eye where the peripheral vision degenerates due to pressure within the eyeball.  This pressure can be relieved by applying beta-blocker eye drops, a much less invasive treatment compared to surgery.

Beta blockers are also getting utilized in the “psycho ward”; namely, when one suffers from anxiety and the physical manifestations like palpitations, tremors, shortness of breath and sweating.  Migraine sufferers can also breathe a sigh of relief and sing praises for beta blockers.

However, as promising as it sounds, beta blockers are not without caveat.  They should never be taken, or taken with close supervision, by:

  • People who have a history of asthma and bronchospasm;
  • Patients suffering from second or third degree heart block;
  • Patients suffering from peripheral arterial disease;
  • Patients who have serious heart failure (surgery is the only option);
  • Women who are breastfeeding, pregnant or suspecting they are pregnant;
  • Diabetics;
  • People who have slow heart rate (as interrupting nerve signals could result to lower cardiovascular activity).