A Case Report of Hemodialysis Patient with Successful Determination of Pilsicainide and Digoxin Dosage by Therapeutic Drug Monitoring.

( Received October 7,1999 Accepted March 27, 2000 ) A 67-year-old man who had been receiving hemodialysis (HD) was administered pilsicainide and digoxin for the treatment of paroxysmal atrial fibrillation. Thereafter, when undergoing HD, ventricular fibrillation and flutter frequently appeared, and he was therefore admitted to National Cardiovascular Center. After being admitted, the administration of pilsicainide and digoxin was immediately stopped due to a widening QRS on ECG. After that the terminal half-time (t1/2) of pilsicainide and digoxin were calculated and these drugs were restarted base on his calculated t1/2. Subsequently a good control of arrhythmia without any side effects was obtained at this dosage. The above findings suggested that although the dose of digoxin in this case ranged from onesixth to one-third of the normal dose when the renal function was normal, the dose of pilsicainide was only about one-tenth that of a normal dose, and a remarkable difference was observed between the dose of digoxin and pilsicainide. This case suggests that drugs, which are mainly eliminated in the kidney, especially pilsicainide, should thus be carefully monitored regarding their influence on the renal function in HD patients, since such therapy could lead to renal function failure.