Beta blockers are a class of medications that slow the heart rate down by blocking the beta receptors of the heart. By reducing the heart rate the heart it ultimately does not have to work harder thereby, it uses less energy and resources. This reduced workload reduces the strain on the heart that ultimately makes the heart work more efficiently. That's the whole point of them.
By using these medications there are side effects, as with any other medications, not only does it get the most wanted response by reducing the heart it also affects other systems that have the same receptors.
There are 3 types of receptors, beta 1 receptors are found in the heart and when activated the result is a fast heart rate. Beta 2 receptors are found less in the heart and mostly in the lungs and smooth muscle. Smooth muscle is found in the veins, arteries and digestive system. Beta 3 receptors are found in the fat tissues but less in the heart and when activated causes the body to warm up in a process called thermogenesis.
Medications are not always smart. They are just chemicals that affect certain processes. These chemicals block beta receptors. Whenever the medications come across a beta receptor it plugs it up rendering it useless. If the goal of treatment is to slow the heart down so it can conserve more energy then there are certain receptors it needs to "plug" up in order to achieve that goal.
Some of the drugs are selective, meaning they only work on one particular receptor and others are non selective meaning once they come across a beta receptor it just plugs it up whether it's in the heart or not.
When someone is on these medications for a long time it can lead to the beta receptors being more sensitive and therefore if therapy is stopped suddenly it can increase the chance of angina, MI or death.
Beta blockers can either be excreted in the liver or kidneys. If they
are problems in the liver or kidney such as inflammation these organs
don't work as well. Their ability to excrete chemicals is slowed. The
doctors prescribed medicines either once a day twice a day or even three
times a day. If the liver or kidneys can't excrete the chemicals before
the next dose could build up in the blood stream
resulting in higher amounts of the chemicals in the blood than expected.
The more amounts of the medicine that remain in the blood the greater
the beta blocker effect takes place. The net result would be a slower
than expected heart rate.
• acebutolol (Sectral)
• atenolol (Tenormin)
• betaxolol (Kerlone)
• bisoprolol fumarate (Zebeta)
• carvedilol (Coreg)
• esmolol (Brevibloc)
• labetalol (Trandate)
• metoprolol (Lopressor, Toprol XL)
• nadolol (Corgard)
• nebivolol (Bystolic)
• penbutolol (Levatol)
• propranolol (Hemangeol, Inderal LA Inderal XL, InnoPran XL)
• sotalol (Betapace, Sorine)
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