DRONEDARONE HYDROCHLORIDE

Clinical safety rating: caution

Comprehensive clinical and safety monograph for DRONEDARONE HYDROCHLORIDE (DRONEDARONE HYDROCHLORIDE).

How it works

Dronedarone is a benzofuran derivative with antiarrhythmic properties belonging to class III. It blocks multiple ion channels (K+, Na+, Ca2+) and exhibits antiadrenergic effects. It prolongs atrial refractory periods and reduces ventricular rate.

What the body does with it

Metabolism	Metabolized primarily by CYP3A4 to an active metabolite (SR 35021). Also metabolized by MAO-A and CYP2D6 to a lesser extent.
Excretion	Approximately 6% of an oral dose is excreted unchanged in urine. The majority is eliminated as metabolites via biliary excretion into feces (84% of total radioactivity recovered in feces, 6% in urine).
Half-life	Terminal half-life is approximately 24 hours (range 13–31 hours) after multiple dosing. Steady state is reached within 4–8 days. The prolonged half-life supports once-daily dosing but requires caution in renal impairment due to accumulation of inactive metabolites.
Protein binding	>98% bound to plasma proteins, primarily albumin. Concentration-dependent binding is minimal at therapeutic levels.
Volume of Distribution	Apparent volume of distribution is approximately 140 L (1.75 L/kg for a 70 kg adult), indicating extensive extravascular distribution. Higher Vd in females compared to males (due to body composition differences).
Bioavailability	Oral bioavailability is low (approximately 15%) due to extensive first-pass metabolism. Administration with a high-fat meal increases exposure up to 3-fold; therefore, it should be taken with food to ensure consistent absorption.
Onset of Action	Oral: onset of antiarrhythmic effect observed within 2–3 hours after first dose; maximal effect may take several days to weeks.
Duration of Action	Duration of antiarrhythmic action is approximately 24 hours with once-daily dosing, allowing sustained suppression of atrial fibrillation/flutter. Clinical effect may persist for several days after discontinuation.

Classification & Brands

Dosing & administration

400 mg orally twice daily with meals.

Dosage form	TABLET
Renal impairment	No dose adjustment required for mild to moderate renal impairment. Not recommended in severe renal impairment (CrCl <30 mL/min).
Liver impairment	Contraindicated in patients with Child-Pugh Class C hepatic impairment. Use with caution in Child-Pugh Class A and B; no established dose adjustment.
Pediatric use	Safety and efficacy not established; use not recommended in pediatric patients.
Geriatric use	No specific dose adjustment recommended, but monitor for adverse effects due to age-related decreased renal function.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

Comprehensive clinical and safety monograph for DRONEDARONE HYDROCHLORIDE (DRONEDARONE HYDROCHLORIDE).

Breastfeeding	Excreted in rat milk; unknown in humans. M/P ratio not established. Avoid breastfeeding due to potential for severe adverse effects (bradycardia, hepatic toxicity) in the nursing infant.
Teratogenic Risk	Pregnancy Category X. Dronedarone is contraindicated in pregnant women due to documented teratogenicity in animal studies (fetal cardiovascular defects, skeletal abnormalities). Human data limited; risk in first trimester includes major malformations. Second/third trimester may cause fetal thyroid dysfunction, bradycardia, and growth restriction.

Warnings & precautions

■ FDA Black Box Warning

Contraindicated in patients with NYHA Class IV heart failure or NYHA Class II-III heart failure with a recent decompensation requiring hospitalization or referral to a specialized heart failure clinic. Increased risk of death in such patients.

Side Effect Profile

Serious Effects

Absolute Contraindications

NYHA Class IV heart failure, NYHA Class II-III heart failure with recent decompensation, second- or third-degree atrioventricular block, sick sinus syndrome, bradycardia <50 bpm, concomitant use of strong CYP3A4 inhibitors, QTc interval ≥500 ms, permanent atrial fibrillation, severe hepatic impairment, pregnancy.

Clinical Precautions

Precautions

May increase risk of cardiovascular death in patients with heart failure or left ventricular systolic dysfunction. Monitor serum creatinine and potassium levels. Avoid use with QT-prolonging drugs. Use with caution in patients with hepatic impairment.

Clinical Tips & Counseling

Drug interactions

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DRONEDARONE HYDROCHLORIDE

Clinical safety rating: caution

Comprehensive clinical and safety monograph for DRONEDARONE HYDROCHLORIDE (DRONEDARONE HYDROCHLORIDE).

How it works

What the body does with it

Metabolism	Metabolized primarily by CYP3A4 to an active metabolite (SR 35021). Also metabolized by MAO-A and CYP2D6 to a lesser extent.
Excretion	Approximately 6% of an oral dose is excreted unchanged in urine. The majority is eliminated as metabolites via biliary excretion into feces (84% of total radioactivity recovered in feces, 6% in urine).
Half-life	Terminal half-life is approximately 24 hours (range 13–31 hours) after multiple dosing. Steady state is reached within 4–8 days. The prolonged half-life supports once-daily dosing but requires caution in renal impairment due to accumulation of inactive metabolites.
Protein binding	>98% bound to plasma proteins, primarily albumin. Concentration-dependent binding is minimal at therapeutic levels.
Volume of Distribution	Apparent volume of distribution is approximately 140 L (1.75 L/kg for a 70 kg adult), indicating extensive extravascular distribution. Higher Vd in females compared to males (due to body composition differences).
Bioavailability	Oral bioavailability is low (approximately 15%) due to extensive first-pass metabolism. Administration with a high-fat meal increases exposure up to 3-fold; therefore, it should be taken with food to ensure consistent absorption.
Onset of Action	Oral: onset of antiarrhythmic effect observed within 2–3 hours after first dose; maximal effect may take several days to weeks.
Duration of Action	Duration of antiarrhythmic action is approximately 24 hours with once-daily dosing, allowing sustained suppression of atrial fibrillation/flutter. Clinical effect may persist for several days after discontinuation.

Classification & Brands

Dosing & administration

400 mg orally twice daily with meals.

Dosage form	TABLET
Renal impairment	No dose adjustment required for mild to moderate renal impairment. Not recommended in severe renal impairment (CrCl <30 mL/min).
Liver impairment	Contraindicated in patients with Child-Pugh Class C hepatic impairment. Use with caution in Child-Pugh Class A and B; no established dose adjustment.
Pediatric use	Safety and efficacy not established; use not recommended in pediatric patients.
Geriatric use	No specific dose adjustment recommended, but monitor for adverse effects due to age-related decreased renal function.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

Comprehensive clinical and safety monograph for DRONEDARONE HYDROCHLORIDE (DRONEDARONE HYDROCHLORIDE).

Breastfeeding	Excreted in rat milk; unknown in humans. M/P ratio not established. Avoid breastfeeding due to potential for severe adverse effects (bradycardia, hepatic toxicity) in the nursing infant.
Teratogenic Risk	Pregnancy Category X. Dronedarone is contraindicated in pregnant women due to documented teratogenicity in animal studies (fetal cardiovascular defects, skeletal abnormalities). Human data limited; risk in first trimester includes major malformations. Second/third trimester may cause fetal thyroid dysfunction, bradycardia, and growth restriction.