Suggested Transition from Oral to Intravenous Amiodarone Therapy

Abstract

Objective:

To provide clinicians with a basis from which to decide the appropriate intravenous dosage of amiodarone in patients who are currently taking oral amiodarone.

Data Sources:

English-language articles describing the pharmacokinetics of amiodarone were collected through literature searches of the Index Medicus database over a period of approximately 4 years. Reference lists from the publications were reviewed to search further for original articles.

Study Selection:

Data were rejected only if there was reason to doubt the validity of the pharmacokinetic parameters reported. For example, dose administration, sample collection times, and pharmacokinetic analysis procedures had to be clearly stated.

Data Extraction:

Data describing the pharmacokinetics, particularly the half-life, of amiodarone after discontinuation of long-term oral treatment were extracted from the articles.

Data Synthesis:

No formal methods were used to combine the data.

Conclusions:

Based on pharmacokinetic considerations, no intravenous replacement treatment is necessary in patients for whom oral administration is contraindicated for less than 2 weeks and who have received adequate loading doses of amiodarone. Intravenous amiodarone may be administered at half the dosage of oral amiodarone, assuming a bioavailability of 50%, to patients for whom oral administration is contraindicated for an undetermined time or in whom a steady-state concentration is unlikely to have been reached.