Lanthanum carbonate is an efficacious noncalcium, nonresin phosphate-binder that is being increasingly used in chronic kidney disease stage 5 (CKD-5) dialysis patients. Available evidence has indicated that QT interval changes correlate with mortality in healthy subjects and in dialysis patients. Experimental studies have suggested the possibility that lanthanum carbonate may produce prolongation of the QT interval. This is not accepted by other authors. There is no data confirming this in prospective clinical studies. The goal of this study was to verify the effect of lanthanum carbonate on the QT interval of the electrocardiogram (EKG) tracing.
Material and methods: We studied 25 hemodialyzed patients. After a six-month run-in period, with aluminum-hydroxide, lanthanum carbonate was administered at increasing doses: 500 mg twice a day for week 1; 750 mg, twice daily during week 2; 1000 mg twice daily during week 3; and 1000 mg three times daily during week 4. EKGs were recorded on patients prior to and 3 hours following each dialysis treatment. Assessments were made of differences in body weight; systolic blood pressure; diastolic blood pressure; length of PR and QRS complex; heart rate; QT; QT-c; QT-d; and axis of wave P, QRS complex and T using lanthanum carbonate at increasing doses.
Results: QT-c is before dialysis session during run-in 431 ± 20 msec with variation by -9 to + 1 msec (P = not significant [NS]) during lanthanum use; and 437 ± 25 msec after dialysis session with variation by -6 to -1 msec (P = NS) during lanthanum use. Any difference was observed during study among before and after dialysis session in QT-c (difference by 0.09 to 3.2%) (P = NS); and QT-d (difference by 8.6 to 9.1%) (P = NS).
Conclusion: Our study shows that lanthanum carbonate administration, at increasing doses, did not modify the EKG parameters. This effect is observed both in predialysis and in postdialysis recordings. Further studies are necessary with more prolonged observations.
Keywords: QT dispersion; QT interval; hemodialysis; lanthanum carbonate.