The Debate on β Blockers: To Use or Not To Use?
Written by Shanmathi Murugesan
Edited by Elyse Ehlert
April 5, 2024
Edited by Elyse Ehlert
April 5, 2024
Research
Cardiovascular disease is the leading cause of death in the US, with hypertension (or high blood pressure), being the main contributor to the disease. While there are many ways to combat hypertension with dietary and other lifestyle interventions, medications prove to be the most effective. In their viewpoint article published in The Lancet, Dr. Messerli and colleagues present concern over the recent changes in guidelines of the European Society of Hypertension which promote β blockers, a class of anti-hypertensive medications, as the first treatment recommended for hypertensive patients.
To provide some background, there are five main classes of medications that can be prescribed to lower blood pressure which are (1) ACEIs, (2) ARBs, (3) β Blockers, (4) CCBs, and (5) Thiazide/Thiazide-like diuretics. A quick summary of the mechanisms of action of each class can be found below:
So, why were the guidelines changed in the first place? Because B-blockers can act as twofers, which are drugs that can single-handedly treat multiple conditions. However, the authors point out that such conditions can actually be better treated with other drugs. For example, ARBs and ACEIs result in positive outcomes when used to treat atrial fibrillation, whereas B-blockers do not. When there is substantial evidence to show that CCBs, thiazides, and other classes of medications can protect against stroke more effectively, recommending use of B-blockers is misleading and can lead to worse patient outcomes. Furthermore, B-blockers can also increase risk of stroke when used to treat post myocardial infarction.
One of the main causes of concern stems from the fact that B-blockers do not treat stroke as well as ARBs and CCBs. For example, use of Losartan, an ARB, resulted in a 40% reduction in risk of stroke when compared to use of Atenolol, a B-blocker. Not only were B-blockers less effective than ARBs, but they were reported to be less effective than CCBs, ACEIs, and thiazides as well by the meta-analysis that the guideline authors refer to. Despite the substantial amount of evidence that proves B-blockers are an inferior treatment method, they were still prescribed more than the other classes of anti-hypertensive drugs in the past until guidelines were changed to place them in an inferior status. The recent changes in guidelines which revert the status of B-blockers to first-line therapy can lead to less effective treatment outcomes for hypertensive patients as well as unnecessary side effects, which include impotency and extreme fatigue. While reducing the load of medicines patients need to take is important, giving patients the most effective medications is a higher priority. In that respect, B-blockers should not be used as first-line therapy.
References:
Franz H Messerli, Sripal Bangalore, John M Mandrola, β blockers switched to first-line therapy in hypertension, The Lancet, Volume 402, Issue 10414, 2023, Pages 1802-1804, ISSN 0140-6736, https://doi.org/10.1016/S0140-6736(23)01733-6.
Diuretics - Drug cabinet - Heart Matters magazine - BHF
Comment
Viewpoint
twofer = single drug that treats two conditions
Losartan (ARB)
Atenolol (B-Blocker)
Hydrochlorothiazide (thiazide diuretic)
To provide some background, there are five main classes of medications that can be prescribed to lower blood pressure which are (1) ACEIs, (2) ARBs, (3) β Blockers, (4) CCBs, and (5) Thiazide/Thiazide-like diuretics. A quick summary of the mechanisms of action of each class can be found below:
- (1) Angiotensin-Converting Enzyme Inhibitors (ACEI) : Reduce the activity of an enzyme which increases blood pressure and causes blood vessels to constrict, thereby actually decreasing blood pressure.
- (2) Angiotensin Receptor Blockers (ARB): Block receptors of angiotensin, a hormone which increases blood pressure and causes blood vessels to constrict. Receptors are found on many organs including heart, blood vessels, and kidney.
- (3) β Blockers: Block the release of stress hormones epinephrine (commonly known as adrenaline) and norepinephrine (or noradrenaline) which lowers the force and rate at which heart pumps, in turn reducing the amount of oxygen demand.
- (4) Calcium Channel Blockers (CCB): When calcium flows into our cells, it causes our muscles to contract. By blocking the channels that allow calcium to flow and thereby reducing the amount of calcium that can enter our cells, CCBs prevent heart muscles from contracting and allow the blood vessels to relax. When blood vessels relax, the heart can receive more oxygenated blood.
- (5) Thiazide/Thiazide-like diuretics: Most often prescribed for heart failure, diuretics act by preventing kidneys from retaining too much water and cause them to release it in the form of urine, which also leads to the excretion of sodium, potassium, and magnesium.
So, why were the guidelines changed in the first place? Because B-blockers can act as twofers, which are drugs that can single-handedly treat multiple conditions. However, the authors point out that such conditions can actually be better treated with other drugs. For example, ARBs and ACEIs result in positive outcomes when used to treat atrial fibrillation, whereas B-blockers do not. When there is substantial evidence to show that CCBs, thiazides, and other classes of medications can protect against stroke more effectively, recommending use of B-blockers is misleading and can lead to worse patient outcomes. Furthermore, B-blockers can also increase risk of stroke when used to treat post myocardial infarction.
One of the main causes of concern stems from the fact that B-blockers do not treat stroke as well as ARBs and CCBs. For example, use of Losartan, an ARB, resulted in a 40% reduction in risk of stroke when compared to use of Atenolol, a B-blocker. Not only were B-blockers less effective than ARBs, but they were reported to be less effective than CCBs, ACEIs, and thiazides as well by the meta-analysis that the guideline authors refer to. Despite the substantial amount of evidence that proves B-blockers are an inferior treatment method, they were still prescribed more than the other classes of anti-hypertensive drugs in the past until guidelines were changed to place them in an inferior status. The recent changes in guidelines which revert the status of B-blockers to first-line therapy can lead to less effective treatment outcomes for hypertensive patients as well as unnecessary side effects, which include impotency and extreme fatigue. While reducing the load of medicines patients need to take is important, giving patients the most effective medications is a higher priority. In that respect, B-blockers should not be used as first-line therapy.
References:
Franz H Messerli, Sripal Bangalore, John M Mandrola, β blockers switched to first-line therapy in hypertension, The Lancet, Volume 402, Issue 10414, 2023, Pages 1802-1804, ISSN 0140-6736, https://doi.org/10.1016/S0140-6736(23)01733-6.
Diuretics - Drug cabinet - Heart Matters magazine - BHF
Comment
Viewpoint
twofer = single drug that treats two conditions
Losartan (ARB)
Atenolol (B-Blocker)
Hydrochlorothiazide (thiazide diuretic)