COMPARISON OF SERUM DIGOXIN LEVEL AND CLINICAL RESPONSE IN PATIENTS WITH CHRONIC ATRIAL FIBRILLATION IN TWO DIFFERENT WAYS OF CONTINUOUS AND INTERRUPTED USE

Abstract

Background- Digoxin prescription with an interruption of one or two days a week is ‎frequently used in Iran. We compared this kind of digoxin prescription with an ‎uninterrupted one through the determination of serum digoxin level and clinical ‎response in Iranian patients<br />‎‏.‏ Methods- This study was designed as a crossover clinical trial on 28 patients suffering ‎from chronic atrial fibrillation (AF), and the two different methods of digoxin ‎prescription were compared through achieving therapeutic range of serum digoxin ‎level and clinical response as control of heart rate in patients with chronic AF‏.‏ Results- The serum digoxin concentration in interrupted consumption, the day before ‎‎(0.885 ± 0.29 ng/ml) and after (0.614 ± 0.35 ng/ml) interruption was significantly ‎lower than the continuous form (1.157 ± 0.3 ng/ml), p < 0.05. About 35% of the ‎patients in the interrupted schedule of digoxin had plasma levels lower than 0.8 ng/ml ‎‎(minimum therapeutic range), compared with no one in the continuous schedule. Also ‎none of the patients in the continuous consumption group showed clinical and/or ‎electrocardiographic signs of digoxin toxicity. The mean heart rate in interrupted use ‎on the day before (84.82 ± 7.2 beats/min) and after (86.5 ± 3.8 beats/min) interruption ‎was significantly higher than that in the continuous form (75.9 ± 5.2 beats/ min), p < ‎‎0.05‎‏.‏ ‎<br />‎ Conclusion- This study showed that the continuous use of digoxin has the advantage ‎of achieving the therapeutic range and better controlling the heart rate in patients with ‎AF rhythm and could be the preferred form of prescription in the majority of our ‎patients, as it is in nearly all the countries around the world (Iranian Heart Journal 2003; 4 ‎‎(4):6367).‎