Digoxin

INTRODUCTION

Indications

Treatment of congestive heart failure (CHF). Tachyarrhythmias: Atrial fibrillation and atrial flutter (slows ventricular rate), Paroxysmal atrial tachycardia.

Action

Increases the force of myocardial contraction. Prolongs refractory period of the AV node. Decreases conduction through the SA and AV nodes. Therapeutic Effects: Increased cardiac output (positive inotropic effect) and slowing of the heart rate (negative chronotropic effect).

Adverse Reactions/Side Effects

CNS: fatigue, headache, weakness. EENT: blurred vision, yellow or green vision. CV: ARRHYTHMIAS, bradycardia, ECG changes, AV block, SA block. GI: anorexia, nausea, vomiting, diarrhea. Endo: gynecomastia. Hemat: thrombocytopenia. Metab: electrolyte imbalances with acute digoxin toxicity.

PHYSICAL THERAPY IMPLICATIONS

Examination and Evaluation

• Assess heart rate, ECG, and heart sounds, especially during exercise (See Appendices G, H). Although intended to treat certain atrial arrhythmias, digoxin can precipitate new and potentially serious arrhythmias (proarrhythmic effect). Report any rhythm disturbances or symptoms of increased arrhythmias, including palpitations, chest pain, shortness of breath, fainting, and fatigue/weakness.

• Assess signs and symptoms of CHF (dyspnea, rales/crackles, peripheral edema, jugular venous distention, exercise intolerance) to help document whether drug therapy is effective in reducing these symptoms.

• Be alert for signs of digitalis toxicity. In adults and older children, the first signs of toxicity usually include abdominal pain, anorexia, nausea, vomiting, visual disturbances, bradycardia, and other arrhythmias. In infants and small children, the first symptoms of overdose are usually cardiac arrhythmias. If these appear, notify physician immediately. Blood tests may be needed to monitor digoxin levels, and adjustments in dosage may be indicated.

• Assess balance and risk of falls (See Appendix E), especially in older patients or in patients with weakness, fatigue, or blurred vision.

• Monitor and report signs of thrombocytopenia, including bruising, nose bleeds, and bleeding gums.

Interventions

• Design and implement aerobic exercise and endurance training programs to improve myocardial pumping ability and reduce symptoms of CHF.

• Use caution during aerobic exercise and endurance conditioning because of an increased risk of cardiac arrhythmias (bradycardia, tachycardia, others). Terminate exercise if patient exhibits untoward symptoms (chest pain, shortness of breath, etc.) or displays other criteria for exercise termination (See Appendix L).

Patient/Client-Related Instruction

• Remind patients to take medication as directed to control CHF or atrial arrhythmias, even if they are asymptomatic.

• Instruct patients to weigh themselves every day, and call their physician if they gain 3 or more lbs in 1 day or more than 5 lb in 1 week. Sudden weight gain may indicate fluid buildup due to worsening heart failure.

• Counsel patients about additional interventions to help control ...