Long-term low-dose cibenzoline in patients with chronic renal failure undergoing hemodialysis.

Because most anti-arrhythmic drugs are eliminated from the kidney, anti-arrhythmic drug therapy is largely restricted in patients undergoing hemodialysis (HD). Cibenzoline is a widely used antiarrhythmic drug excreted mainly from the kidney. The present study evaluated the safety and efficacy of reduced doses of cibenzoline (25 and 50 mg/day chronically) in 8 patients with maintenance HD. Cibenzoline was administered for more than 3 months without any problems in 7 of the 8 patients, although the medication was discontinued in 1 patient due to nausea and anorexia. With cibenzoline administration, the incidence and duration of atrial fibrillation decreased or disappeared in 6 of 7 patients and the frequency of complex ventricular arrhythmias was also reduced in 3 of 4 patients. No adverse side effects were noted. Plasma concentration of cibenzoline ranged from 169 to 220 ng/ml with the 25-mg/day dosage, and from 408 to 500 ng/ml with the 50-mg/day dosage. The concentrations remained stable during the study. In conclusion, low doses of cibenzoline are safe and effective in patients undergoing maintenance HD. However, intermittent monitoring is essential to ensure therapeutic drug concentrations.