Comparative Efficacy of 100-, 200-, & 400-mg Amiodarone in Patients With Paroxysmal AF Depending on Plasma Concentration

Amiodarone is a highly effective drug for the treatment and prevention of arrhythmias. In the 1970s and 1980s, numerous experimental and clinical studies comprehensively examined the mechanisms of amiodarone's antiarrhythmic action, as well as its effectiveness in various types of arrhythmias. This explains why drug therapy is so widespread today. According to the CAMIAT study, which included 1,202 patients with ventricular extrasystole who had suffered a myocardial infarction, amiodarone administration reduced the risk of arrhythmic death by 48.5%, and by 35% in the EMIAT study. In the GESICA study, amiodarone therapy was documented to reduce overall mortality by 45%, the incidence of sudden cardiac death by 54%, and mortality from progressive heart failure by 40%. In Russia, amiodarone is prescribed as a first-line drug for AF in 41% of cases with organic myocardial disease, in 52% as a second-line drug, and in 12.5% in the absence of organic heart damage. Moreover, the effectiveness of maintaining sinus rhythm in atrial fibrillation varies from 30 to 95.2%, which is a significant range when predicting the effectiveness of treatment. Attempts to assess amiodarone concentrations during therapy and to analyze the correlation with the achieved effects have been made repeatedly. While assessing amiodarone concentrations is generally considered inappropriate, based on the results of numerous studies, the use of monitoring is justified in certain clinical situations where the desired clinical effect or adverse events are absent. A detailed analysis of systemic reviews revealed significant shortcomings in the formation of such judgments. The groups were heterogeneous, small in number, and included, among other things, individual clinical situations and different routes of drug administration. A literature review did not reveal any data on the analysis of the concentration of amiodarone and desethylamiodarone as an anti-relapse therapy for atrial fibrillation when used consistently in doses acceptable by clinical guidelines with the possibility of titration under laboratory monitoring.