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
. 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.
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).