Amiodarone
Generic Name
Brand Names
Pronunciation
LASA Warnings
Pharmacologic Class
ISMP High-Alert
DEA Schedule
Pregnancy & Lactation
Category D; crosses placenta, may cause fetal thyroid dysfunction. Excreted in breast milk; avoid breastfeeding.
Black Box Warning
Pulmonary toxicity: interstitial pneumonitis, pulmonary fibrosis – may be fatal. Hepatotoxicity: acute liver injury, cirrhosis. Proarrhythmia: exacerbation of arrhythmias. Use only for life‑threatening arrhythmias.
Mechanism of Action
Blocks myocardial K⁺ channels (IKr, IKs), prolonging action potential duration and refractory period. Also blocks Na⁺ channels (Class I), non‑competitively blocks β‑adrenergic receptors (Class II), and blocks Ca²⁺ channels (Class IV). Reduces AV nodal conduction and sinus node automaticity.
Receptor Binding
Weak β‑receptor blockade; antithyroid effects (inhibits peripheral T4 → T3 conversion).
Cellular Transport
Passive diffusion; accumulates in adipose tissue due to high lipophilicity.
Barrier Penetration
Pharmacokinetics
Pharmacogenomics
CYP3A4 polymorphisms may affect clearance; no routine testing recommended.