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esmolol (es-moe-lole)



Therapeutic: antiarrhythmics (class II)

Pharmacologic: beta blockers


Management of sinus tachycardia and supraventricular arrhythmias.


Blocks stimulation of beta1 (myocardial)-adrenergic receptors. Does not usually affect beta2 (pulmonary, vascular, or uterine)–receptor sites. Therapeutic Effects: Decreased heart rate. Decreased AV conduction.

Adverse Reactions/Side Effects

CNS: fatigue, agitation, confusion, dizziness, drowsiness, weakness. CV: hypotension, peripheral ischemia. GI: nausea, vomiting. Derm: sweating. Local: injection-site reactions.


Examination and Evaluation

  • Assess heart rate, ECG, and heart sounds, especially during exercise (See Appendices G, H). Although intended to treat certain arrhythmias, this drug can unmask or precipitate new arrhythmias (proarrhythmic effect). Report immediately an abnormally slow heart rate (bradycardia) or symptoms of other arrhythmias, including palpitations, chest pain, shortness of breath, fainting, and fatigue/weakness.

  • Assess blood pressure periodically and compare to normal values (See Appendix F). Report low blood pressure (hypotension), especially if patient experiences dizziness or syncope.

  • Monitor signs of peripheral ischemia, such as extreme coldness in the hands and feet, cyanosis, and muscle cramping. Notify physician of severe or prolonged signs of vasoconstriction.

  • Assess dizziness and drowsiness that might affect gait, balance, and other functional activities (See Appendix C). Report balance problems and functional limitations to the physician and nursing staff, and caution the patient and family/caregivers to guard against falls and trauma.

  • Monitor mood and personality changes, including agitation, confusion, or other changes in behavior. Notify physician if these changes become problematic.

  • Monitor excessive fatigue or weakness. Beta blockers often cause some degree of fatigue and weakness, but any sudden or severe change in muscle strength or energy levels should be reported.

  • Monitor IV injection site for pain, swelling, and irritation. Report prolonged or excessive injection-site reactions to the physician.


  • Because of possible effects on cardiac excitation, use caution during aerobic exercise and endurance conditioning. Terminate exercise if patient exhibits untoward symptoms (chest pain, shortness of breath, unusual fatigue) or displays other criteria for exercise termination (See Appendix L).

  • Establish aerobic exercise workloads that account for the effects of beta blockers on heart rate (HR). Some HR guidelines may not be appropriate because beta blockers typically decrease maximal HR by 20–30 bpm. Use other guidelines such as rating of perceived exertion (RPE, modified Borg scale) to determine exercise workloads.

  • To minimize orthostatic hypotension, patient should move slowly when assuming a more upright position.

Patient/Client-Related Instruction

  • Counsel patients about additional interventions to help control cardiac arrhythmias, including regular exercise, caffeine restriction, stress reduction, moderation of alcohol consumption, and smoking cessation.

  • Instruct patient or family/caregivers to report other troublesome side effects ...

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