Retrospective analysis of the effects of cisapride on the QT interval and QT dispersion in chronic hemodialysis patients

Cisapride is contraindicated in patients with end-stage renal disease (ESRD ) and gastrointestinal motility disorders. Ventricular arrhythmias have bee n associated with both cisapride and hemodialysis (HD). However, reports co nflict regarding the safety of cisapride in HD patients. We undertook this study to characterize the effects of cisapride on QT intervals and QT dispe rsion (QTD) in HD patients. Baseline and steady-state electrocardiograms (E CGs) were retrospectively selected for calendar year 1999 for each patient administered cisapride if ECGs showed sinus rhythm, potassium level was 3.5 mEq/dL or greater, and there was no pharmacokinetic drug interaction. QT i ntervals were measured by two investigators, and QTDs were calculated (maxi mum [QT(max)]-minimum QT interval [QT(min)]). Averages between investigator measures ( SD), presented for each value, were evaluated using Wilcoxon's signed-rank test. Thirty-one HD patients were administered cisapride. Seven teen patients failed to meet entry criteria, and no patient had a pharmacok inetic drug interaction. In included patients (6 men, 8 women), heart rates were 86.71 +/- 20.87 beats/min at baseline and 86.57 +/- 14.23 beats/min d uring treatment (P = not significant). Serum potassium levels were 4.97 +/- 1.2 mEq/dL at baseline and 4.94 +/- 0.76 mEq/dL during treatment (P = not significant). Average baseline QT(max) and QT(min) were 391.07 +/- 42.43 an d 330.71 +/- 40.94 milliseconds, respectively. Treatment QT(max) and QT(min ) were 391.43 +/- 38.2 and 343.93 +/- 35.69 milliseconds, respectively (P = not significant for both). QTD was 60.36 +/- 17.59 milliseconds at baselin e and 47.5 +/- 19.59 milliseconds during treatment (P = 0.074). Mean correc ted QT (QTc) intervals increased from 426.57 +/- 26.62 to 431.71 +/- 29.98 milliseconds (P = 0.55) from baseline to treatment. No ventricular arrhythm ia was observed during at least 160 days (range, 2 to 830 days) of cisaprid e exposure. Two patients died during this study, both of other causes 4 day s after discontinuing cisapride therapy. Cisapride did not significantly in crease mean QTc interval, QT(max) or QTD in patients with ESRD managed by H D when potassium levels were stable and pharmacokinetic drug interactions w ere avoided. (C) 2001 by the National Kidney Foundation, Inc.