Pharmacokinetics of amiodarone: implications for drug therapy

Amiodarone is a complex molecule with multiple pharmacologic properties and a complex electrophysiologic profile. Its disposition kinetics and relation between plasma drug concentration and efficacy can be analyzed using principles identical to those applicable to other antiarrhythmic drugs. However, the drug's affinity for lipophilic tissues, its extremely slow elimination rate, and the likelihood that some of its effects may not be mediated by the usual antiarrhythmic mechanisms confounds traditional pharmacokinetic analysis. Further data that deal with the fundamental mechanisms of action of the drug, in addition to the nature of the relation between dose and uptake into cellular and subcellular fractions and its pharmacologic effects, will be of value in understanding how the drug exerts salutary actions in cardiac arrhythmias.