Dronedarone

INTRODUCTION

Indications

Reduces the risk of hospitalization in patients with paroxysmal or persistent atrial fibrillation (AF) or atrial flutter (AFl), who have had a recent episode of AF/AFl and have other cardiovascular risk factors and are currently in sinus rhythm or plan to be cardioverted.

Action

Has several antiarrhythmic properties; prolongs PR and QTc intervals. Therapeutic Effects: Suppression of AF/AFI.

Adverse Reactions/Side Effects

CNS: weakness. CV: CHF, QTc prolongation. GI: abdominal pain, diarrhea, nausea, taste abnormality, vomiting. Derm: photosensitivity.

PHYSICAL THERAPY IMPLICATIONS

Examination and Evaluation

• Watch for signs of congestive heart failure, including dyspnea, rales/crackles, peripheral edema, jugular venous distention, and exercise intolerance. Report these signs to the physician immediately.

• 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 any rhythm disturbances (QTc prolongation) or symptoms of increased arrhythmias, including palpitations, chest pain, shortness of breath, fainting, and fatigue/weakness.

Interventions

• Because of the risk of CHF and cardiac rhythm disturbances, use caution during aerobic exercise and other forms of therapeutic exercise. Assess exercise tolerance frequently (blood pressure, heart rate, fatigue levels), and terminate exercise immediately if any untoward responses occur (See Appendix L).

• Causes photosensitivity; use care if administering UV treatments. Advise patient to avoid direct sunlight and use sunscreens and protective clothing.

Patient/Client-Related Instruction

• Advise patient and family or caregivers about the signs of arrhythmias and CHF (See above under Examination and Evaluation), and to seek immediate medical assistance if these signs develop.

• Instruct patient and family/caregivers to report other side effects such as severe or prolonged weakness or GI problems (nausea, vomiting, diarrhea, abnormal taste, abdominal pain).

Pharmacokinetics

Absorption: Poor bioavailability (4%) due to extensive first pass hepatic metabolism (4%); food ↑ bioavailability (15%).

Distribution: Unknown

Protein Binding: >98%.

Metabolism and Excretion: Undergoes extensive first-pass hepatic metabolism; mostly by the CYP3A enzyme system. 6% excreted in urine as metabolites; 84% was excreted in feces as metabolites. Minimal elimination as unchanged drug.

Half-life: 13–19 hr.

Contraindications/Precautions

Contraindicated in: Class IV heart failure or class II–III heart failure with recent ...