Beta blockers are medications that help decrease blood pressure, slow down the heart rate, and treat dysrhythmias. This review will discuss the mechanism of action of beta blockers, what conditions they treat, nursing implications, side effects, and patient education. Show Don’t forget to take the beta blockers quiz after reviewing this material. Beta Blockers LectureBeta Blockers Nursing Pharmacology ReviewName?Beta blockers block the BETA receptors sites in the body so norepinephrine and epinephrine can NOT bind to the receptor site and elicit a sympathetic nervous system response. Sympathetic nervous system: it’s the “fight or flight system”….it works to save your life from danger. When BETA receptors sites are stimulated by the SNS and have norepinephrine and epinephrine bind to them, the person can experience (note these are just some of the responses created by the sympathetic nervous system):
Beta blockers will block many of these actions, and this can be helpful in certain conditions when the workload of the heart needs to be decreased or the heart is beating too fast (dysrhythmias). It’s very important to know that there are different types of beta receptors in the body….beta 1, beta 2, and beta 3. Beta 1 receptors are mainly located in the HEART (remember you have one heart) and in the kidneys (specifically the juxtaglomerular cells that release renin). Beta 2 receptors are located in the bronchioles of the LUNGS (remember you have two lungs), GI system, vascular smooth muscle and skeletal muscle, and ciliary body of the eye. Beta 3 receptors are located in the fatty/adipose tissue of the body. Types of Beta BlockersAll generic beta blockers names end in “LOL”. Selective beta blockers are selective to only beta 1 receptors. These medications are sometimes referred to as cardioselective because they mainly target the heart since it’s mainly made up of beta 1 receptors.
Nonselective beta blockers block BOTH beta 1 and beta 2 receptors. They’re not selective to one certain type of beta receptor. Therefore, they will target the heart and kidneys too, but will also target the GI system, LUNGS, vascular smooth muscle etc. These medications have more of a peripheral effect than the selective beta blockers. It’s important to remember what patient populations cannot take the nonselective beta blockers and side effects they may cause for exams.
Mechanism of Action of Beta Blockers (how they affect the body)
Used For?Hypertension, stable angina (CAD), dysrhythmias (example SVT), compensated heart failure, migraines, glaucoma (example: Timolol), tremors, anxiety Side Effects, Responsibilities, Education?“Beta Block”Bradycardia and blocks….2 or 3 degree heart blocks
Exacerbate heart failure due to negative inotropic effect
Taper off (beta blockers are typically tapered off over 2 weeks or so)… TEACH patient to NEVER just stop taking because the body will have withdrawal issues like rebound hypertension, ischemia that leads to angina etc. Asthma & COPD patients can’t have nonselective beta blockers due to bronchoconstriction… Propranolol, Sotalol, Timolol etc. Blood glucose monitored closely in diabetes (TEACH). They need to monitor for hypo/hyperglycemic AND the masking of hypoglycemia due to NO TACHYcardia experienced with blood glucose drops. Low blood pressure (hypotension)…TEACH patient to monitor blood pressure at home. Orthostatic hypotension: monitor and teach….slowly changes positions when going from a sitting to lying position to standing. Circulation impaired due to peripheral vasoconstriction (NONselective)
Know overdose signs and symptoms: Bradycardia, heart blocks, low blood pressure, mental status changes: very lethargic or fainting, difficulty breathing due to bronchospasm, heart block… TEACH patient to monitor for these as well. References:
Food and Drug Administration (FDA.gov). Tenormin (atenolol) Tablets [Ebook]. Retrieved from https://www.accessdata.fda.gov/drugsatfda_docs/label/2011/018240s031lbl.pdf Food and Drug Administration (FDA.gov). Inderal (propranolol hydrochloride) Tabelts [Ebook]. Retrieved from https://www.accessdata.fda.gov/drugsatfda_docs/label/2011/016418s080,016762s017,017683s008lbl.pdf |