Cardiac Glycosides:
Actions and Uses

Cardiac glycosides slow and strengthen the heartbeat by affecting the natural electrical system of the heart. Cardiac glycosides most often are used to treat severe heart failure heart and atrial fibrillation that can occur with congenital heart defects. One of the medications that is used to treat cardiac glycosides is digoxin. It sometimes takes several weeks to determine the correct dose of this medicine. Cardiac glycosides most often are taken as pills but are also available in liquid form.
Cardiac glycosides help:
- Control rapid irregular heartbeats.
- Reduce the backup of blood and fluid in the body that can cause swelling in the arms and legs and difficulty breathing.
- Increase blood flow through the kidneys, which helps get rid of salt (sodium) and relieves swelling in the tissues of the body.


Side effects and adverse effects
The most common side effects of cardiac glycosides include: Buildup of the medicine in the body.
Symptoms include:
Confusion
Nausea
Loss of appetite
Trouble with vision
Slow (bradycardia) or rapid (tachycardia) heartbeats, especially in people who are also taking diuretics.

Nursing Implications
Excessive slowing of the pulse rate (under 60 beats per minute or less) should be taken into consideration and notification of the health care provider is suggested. Patients that have hyperthyroidism are very sensitive to cardiac glycosides and should be given lower doses. Monitor potassium levels carefully, take the correct action before hyperkalemia occurs. Don't confuse digoxin with doxepin.


Antianginals
Actions and Uses

Antianginals are medicines that treat or prevent chest pain (angina) associated with heart disease. Antianginal medicines work by widening (dilating) blood vessels that supply blood to the heart muscle.
Examples of antianginal medicines are:
Nitrates.
Nitroglycerin (such as Nitro-Dur, Nitrolingual, Nitrostat)
Isosorbide dinitrate (such as Dilatrate-SR, Isordil)
Beta-blockers (such as atenolol or metoprolol).
Calcium channel blockers (such as amlodipine).

Side effects and adverse effects
Headache, dizziness, light-headedness, nausea, vomiting, edema, orthostatic hypotension, flushing, tachycardia


Nursing Implications
Monitor patients carefully, especially those with obstructive coronary artery disease. Monitor blood pressure frequently during initation of drug, notify doctor if signs of heart failure occur, such as swelling of hands and feet of shortness of breath.

Sources
O'Rourke ST (October 2007). "Antianginal actions of beta-adrenoceptor antagonists". Am J Pharm Educ 71 (5): 95. PMID 17998992.

Pfister M, Seiler C, Fleisch M, Göbel H, Lüscher T, Meier B (October 1998). "Nitrate induced coronary vasodilatation: differential effects of sublingual application by capsule or spray". Heart 80 (4): 365–9. PMID 9875113. PMC: 1728824. http://heart.bmj.com/cgi/pmidlookup?view=long&pmid=9875113.

Schilling McCann, J. (Ed.). Antiangials. (2003). In Nursing 2003 Drug Handbook (23rd ed., Springhouse: Lippincott Williams & Wilkins.



Antiarrhythmics
Actions and Uses

Antiarrhythmic medications help return the heart to its normal sinus rhythm , maintain the rhythm after it has been achieved, and/or reduce the heart rate while you are in atrial fibrillation. These medications stabilize the heart muscle tissue. Antiarrhythmics also slow the heart rate by blocking impulses that pass through the AV node in the heart.

Side effects and adverse effects
Antiarrhythmic medications may increase the risk of developing a more severe irregular heart rate problem. Close monitoring while taking the medication is important. The risk of side effects is greater with more severe underlying heart disease.
Side effects of antiarrhythmics include:
Slow heartbeat
Palpitations
Fatigue
Headache
Dizziness
Nausea or vomiting
Unusual taste in the mouth
Stomach pain
Constipation or diarrhea
Difficulty breathing
Rash
Vision problems
Urinary retention in men
Arrhythmia.

Nursing Implications
Monitor patient closely when starting out on medication. Use cautiously in patients with asthma, emphysema, or bronchitis because bronchoconstriction can occur. Monitor EGC for any abnormal rhythm patterns, assess patient for any new or worsened symptoms of heart failure.

Sources
Oral H, et al. (1999). Facilitating transthoracic cardioversion of atrial fibrillation with ibutilide pretreatment. New England Journal of Medicine, 340(24): 1849–1854.

Olgin JE, Zipes DP (2004). Atrial fibrillation section of Specific arrhythmias: Diagnosis and treatment. In DP Zipes et al., eds., Braunwald's Heart Disease, 7th ed., pp. 816–819. Philadelphia: Elsevier Saunders.