Beta blockers are a first-line treatment for high blood pressure and are also added in to other classes of blood pressure treatment if the single drug alone does not control blood pressure. However, beta-blockers (eg acebutolol, atenolol, bisoprolol, celiprolol, carvedolol, labetalol, metoprolol, nadolol, nebivolol, oxprenolol, pindolol, propranolol, timolol) are less commonly used to treat high blood pressure now that more effective treatments, with fewer side effects, are available.
How beta-blockers lower a high blood pressure
The exact way in which beta blockers lower a high blood pressure is not fully understood but is thought to result from a combination of actions which:
- slow the heart rate to around 60 beats per minute
- reduce the force of contraction of the heart
- decrease the workload of the heart (cardiac output)
- change blood vessel dilation or constriction
- reduce sensitivity of blood pressure sensors (baroreceptors) in the larger arteries
- block stress hormone (adrenaline/epinephrine) receptors
- lower secretion of a kidney hormone, renin, which is involved in blood pressure regulation.
On average, a beta-blocker reduces systolic blood pressure (your upper reading) by 9.3 mmHg when used alone.
Clinical trials have found that beta-blockers are associated with a higher relative risk of stroke and new onset diabetes compared with the other blood pressure treatments, but they still have a role to play in some patients.
Beta blockers are sometimes used as a first line treatment in young people with hypertension and in people who have coronary heart disease, as they reduce the work load of the heart. As a result, beta-blockers can significantly reduce the risk of having a second heart attack and may prolong life in high risk individuals.
Because beta blockers also affect receptors in the lungs, they should not be used in people with asthma as they may trigger an asthma attack.
Beta-blockers should not be withdrawn suddenly, but tailed off slowly so that rebound high blood pressure or angina does not result.
Patient information leaflets
To find out more about the most common beta blockers, including their possible side effects, click on the following links. These will take you to a typical Patient Information Leaflet that is found inside a UK pack of these medicines. Always read the patient information leaflet supplied with your own medicine as different preparations vary.
If your blood pressure is raised, self-monitoring is key to maintaining good control.
Click here for advice on choosing a blood pressure monitor to use at home.
Image credit: anat_chant/shutterstock