【藥品性質提示】 根據 2019 AGS Beers Criteria，本藥品為【潛在不適當用藥 (PIM)】，不建議用於永久性心房顫動 (permanent atrial fibrillation)、嚴重或失代償性心臟衰竭 (decompensated heart failure) 之老年人。

治療心律不整 Paroxysmal or persistent atrial fibrillation (AF) or atrial flutter (AFL), with a recent episode of AF/AFL and associated cardiovascular risk factors

Class III Antiarrhythmic Agent
1. Dronedarone is a non-iodinated amiodarone analogue. It exerts antiarrhythmic effects that are similar to all 4 Vaughan-Williams classes; however, the relationship to the clinical effect is unknown.
2. Like amiodarone, dronedarone inhibits the calcium, sodium, and potassium channels and is an alpha- and beta-adrenergic receptor antagonist.
3. Unlike amiodarone, dronedarone has minimal to no inhibitory effect on the alpha- and beta-thyroid receptors.

Absorption:
1. Bioavailability: (1) Without food: 4% (2) With high-fat meal: 15%
2. Time to peak, plasma: 3 to 6 hours
Distribution:
1. Vd: ~1400 L
2. Protein binding: >98%
Metabolism:
Hepatic via CYP3A4 to active N-debutyl metabolite (1/10 to 1/3 as potent as dronedarone) and other inactive metabolites
Excretion:
Feces (84% mainly as metabolites); urine (~6% mainly as metabolites)
Half-life elimination:
13 to 19 hours

1. Permanent atrial fibrillation (sinus rhythm will not or cannot be restored)
2. Symptomatic heart failure (HF with recent decompensation requiring hospitalization or NYHA Class IV symptoms)
3. Second- or third-degree heart block or sick sinus syndrome (except in patients with a functioning artificial pacemaker)
4. Bradycardia (<50 bpm)
5. Concomitant use of strong CYP3A4 inhibitors and drugs or herbal products known to prolong the QT interval
6. Liver toxicity related to previous amiodarone use; severe hepatic impairment
7. Pregnancy; breast-feeding

X ;contraindicated in women who are pregnant

Excretion in breast milk unknown/contraindicated

Significant Considerations
1. Heart failure: new onset or worsening heart failure symptoms have been observed; risk of death is doubled when used in patients with recent decompensation requiring hospitalization or NYHA Class IV symptoms.
2. Hepatotoxicity: mild to moderate asymptomatic increased liver enzymes; severe hepatic injury with jaundice or acute hepatic failure, with no known therapies for reversing the effects.
3. QTc prolongation: proarrhythmic effects, including ventricular ectopy and prolonged QT interval on ECG (with or without torsades de pointes); moderate prolongation of the QTc interval
4. Pulmonary toxicity: interstitial pulmonary disease (pulmonary fibrosis, pneumonitis), diffuse alveolar damage, bronchiolitis obliterans organizing pneumonia
Common
Prolonged QT interval on ECG, increased serum creatinine
Postmarketing
1. Cardiovascular: Atrial flutter, heart failure, hypersensitivity angiitis, torsades de pointes, vasculitis
2. Dermatologic: Toxic epidermal necrolysis
3. Hepatic: Acute hepatic failure (requiring transplant), hepatic injury, increased liver enzymes
4. Hypersensitivity: Anaphylaxis, angioedema
5. Respiratory: Bronchiolitis obliterans organizing pneumonia, interstitial pulmonary disease, pneumonitis, pulmonary fibrosis

400 mg PO twice daily in adults; should be taken with morning and evening meal.

No dosage adjustment necessary.

1. Mild to moderate impairment: No dosage adjustment necessary.
2. Severe impairment: Use is contraindicated.