| Objective Several great clinical trials proved that amiodarone was an effective antiarrhythmic drug and could induce QT dispersion which was an index of the variation in transmural dispersion of repolarization . Because of the enormous difference among individuals in the aspect of pharmacokinetics, the study on amiodarone's serum concentration was limited. This study was designed to analyze the relationship between the serum concentration of amiodarone and the dosage ,the periods of using it ,the accumulative dosage, QT interval,QT dispersion respectively.It was to discuss the clinical significance of the mensuration of amiodarone's serum concentration.Methods1.Forty patients with arrhythmias were treated with oral amiodarone. The therapeutic effects and adverse effects were obversed.2.The serum concentration of Am and DEA, a primary metabolized substance of Am, were determined by HPLC during the treatment. Of the 40 patients, there were 16 in the loading dosage, 24 in the maintaining dosage. The serum concentration of 6 patients were determined at the end of 2,4,8,12 weeks with the same maintaining dosage.3.QT intervals and QT dispersions were determined before and after the treatment. The formula is'QTd=QTmax-QTmin'.4.The amiodarone's effect on QT interval and QT dispersion and the relationship between the serum concentration and the dosage, the periods of treatment,the accumulative dosage, QTd were analyzed respectively.Resultsl.In this study, amiodarone was effective in treatent of 40 patients including 16 with obvious effects. There were no statistical difference in therapeutic effect between the group with ventricular arrhythmias and the group with atrial arrhythmias. The therapeutic effect had no statistical difference among the groups of different dosage. 2 patients appeared the adverse effects. Their serum concentrations including Am, DEA, Am+DEA and A/D, weren't higher than the average of the group. But their periods of using amiodarone and accumulative dosages were obviously higher than others.2.After the useness of amiodarone,QT interval was obviously increased (383 ± 31ms vs 418±29ms, p<0.05). In the same time QTd was obviously decreased (34 ± 12ms vs 21 ± 9ms,p<0.05).The variation of QT interval and QT dispersion had no statistical difference between the group of loading dosage and the group of maintaining dosage and didn't related with the therapeutic effct.3.The serum concentration with loading dosage was higher than it with maintaining dosage. The difference was significant (p<0.05) .But between the groups of different therapeutic effect,the serum concentr- ation of amiodarone had no statistical difference. The serum concentr- ations of the 6 patients who were determined continuously with the same maintaining dosage decreased along with the periods of treatment prolonged.4.The serum concentration of DEA of the patients given the loading dosage had positive relationship with the period of using amiodarone.The serum concentration of Am of the patients given the maintaining dosage had positive relationship with the dosage.5.In the period with maintaining dosage,the serum concentration of DEA had positive relationship with the increment of QT.But the serum concentration had no relationship with decrement of QTd.Conclusion1.Amiodarone was an effective antiarrhythmic drug to all patients with ventricular arrhythmias and atrial arrhythmias.The occurrence of adverse effects related with the period of using amiodarone and its accumulative dosage and had no relation with the serum concentration of amiodarone.Amiodarone's serum concentration couldn't be an index to estimate the occurrence of adverse effects.2.Amiodarone could increase QT interval and decreased QT dispersion. The variation of QT interval and QT dispersion had no relation with effect and dosage.3. The serum concentration of amiodarone varied in a large range. The serum concentration of Am,DEA and the sum of them all had dosage dependence.They had no relation with the effect.The serum concentration of amiodarone couldn't be an index to...
|
PDF Full Text Request