Abstract | BACKGROUND: After several days of loading, oral amiodarone, a class III antiarrhythmic, is highly effective in controlling ventricular tachyarrhythmias; however, the delay in onset of activity is not acceptable in patients with immediately life-threatening arrhythmias. Therefore, an intravenous form of therapy is advantageous. This study was designed to compare the safety and efficacy of a high and a low dose of intravenous amiodarone with bretylium, the only approved class III antiarrhythmic agent. METHODS AND RESULTS: A total of 302 patients with refractory, hemodynamically destabilizing ventricular tachycardia or ventricular fibrillation were enrolled in this double-blind trial at 82 medical centers in the United States. They were randomly assigned to therapy with intravenous bretylium (4.7 g) or intravenous amiodarone administered in a high dose (1.8 g) or a low dose (0.2 g). The primary analysis, arrhythmia event rate during the first 48 hours of therapy, showed comparable efficacy between the bretylium group and the high-dose (1000 mg/24 h) amiodarone group that was greater than that of the low-dose (125 mg/24 h) amiodarone group. Similar results were obtained in the secondary analyses of time to first event and the proportion of patients requiring supplemental infusions. Overall mortality in the 48-hour double-blind period was 13.6% and was not significantly different among the three treatment groups. Significantly more patients treated with bretylium had hypotension compared with the two amiodarone groups. More patients remained on the 1000-mg amiodarone regimen than on the other regimens. CONCLUSIONS:
Bretylium and amiodarone appear to have comparable efficacies for the treatment of highly malignant ventricular arrhythmias. Bretylium use, however, may be limited by a high incidence of hypotension.
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Authors | P R Kowey, J H Levine, J M Herre, A Pacifico, B D Lindsay, V J Plumb, D L Janosik, H A Kopelman, M M Scheinman |
Journal | Circulation
(Circulation)
Vol. 92
Issue 11
Pg. 3255-63
(Dec 01 1995)
ISSN: 0009-7322 [Print] United States |
PMID | 7586312
(Publication Type: Clinical Trial, Comparative Study, Journal Article, Multicenter Study, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)
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Chemical References |
- Anti-Arrhythmia Agents
- Bretylium Tosylate
- Amiodarone
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Topics |
- Aged
- Amiodarone
(administration & dosage, adverse effects)
- Anti-Arrhythmia Agents
(administration & dosage, adverse effects)
- Bretylium Tosylate
(administration & dosage, adverse effects)
- Dose-Response Relationship, Drug
- Double-Blind Method
- Female
- Humans
- Infusions, Intravenous
- Male
- Middle Aged
- Recurrence
- Tachycardia, Ventricular
(drug therapy, mortality)
- Time Factors
- Ventricular Fibrillation
(drug therapy, mortality)
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