BETA BLOCKERS

Beta blockers are a type of medication that decreases the workload of the heart thus decreasing the oxygen demands of the heart.  Beta blockers decrease heart rate and blood pressure.  Beta blockers are used routinely in patients with acute coronary syndrome and in patients with some types of heart failure.

Beta blockers block certain actions of the sympathetic nervous system, by blocking the beta receptors in the heart. Blocking the beta receptors of the heart keep the heart from reacting to the stress response that releases adrenaline, this in turn  increases the heart rate and workload of the heart.

By blocking the beta receptors in the heart beta blockers slow the heart rate and reduce the force of the contraction of the heart muscle.

There are two types of beta blockers:

     *Selective beta antagonists.  These drugs only block beta 1 receptors,
        which are found primarily in the cardiac muscle.

      *Nonselective beta antagonists:  These drugs block beta 1 and beta 2
        receptors.  Beta 2 receptors are found in the bronchial and peripheral
        vascular smooth muscle.  Nonselective beta antagonists may be more
        likely to exacerbate asthma due to the bronchoconstriction that they can
        cause.

When a physician prescribes a beta blocker they usually start with a low dose and then titrate the dose up as the patient tolerates it.  The reason for this is that this type of drug will lower the heart rate, which in turn can cause lightheadedness and decreased blood pressure.

A few examples of beta blockers are as follows:  atenolol, carvedilol, latetalol, metoprolol sotalol.  Carvedilol is actually a combination alpha and beta blocker.

The following conditions can be treated with beta blockers:  hypertension, angina, myocardial infarction, heart failure, arrhythmias, hypertrophic cardiomyopathy.  There are other conditions that beta blockers may be used for but they do not pertain to our particular focus.

The following are side affects that one should be aware of when taking care of a patient that is on a beta blocker.  Bradycardia, heart block, fatigue, dizziness, diarrhea, constipation and or nausea, and  exacerbation of COPD.  There are other side affects but these are the main ones that one would want to monitor for closely.

Patients should be instructed to never abruptly stop taking their beta blocker as this may lead to angina or myocardial infarction. If they are experiencing side affects they should contact their doctor.

This is just an introduction to the topic of beta blockers in order to help you be aware of one of the type of medications that you can expect to possibly be giving to your patient in the Coronary Care Unit. 

  **Please keep in mind that this web site is an introduction to critical care nursing and does not subscribe to any specific mode of action that would be against the policy of the hospital where you work.  It also is not meant to suggest that any particular medication is the right medication to use.  This page is just to give you a beginning understanding of one type of medication that you might find in your practice in the Coronary Care Unit.

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