Open AccessCardiac repolarization during fingolimod treatment in patients with relapsing–remitting multiple sclerosis
Author(s) -
Laiho Aapo,
Laitinen Tiina M.,
Hartikainen Päivi,
Hartikainen Juha E. K.,
Laitinen Tomi P.,
Simula Sakari
Publication year - 2018
Publication title -
brain and behavior
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.915
H-Index - 41
ISSN - 2162-3279
DOI - 10.1002/brb3.925
Subject(s) - fingolimod , medicine , qt interval , cardiology , multiple sclerosis , repolarization , heart rate , electrophysiology , psychiatry , blood pressure
Background Fingolimod is a sphingosine‐1‐phosphate receptor modulator for the treatment of relapsing–remitting multiple sclerosis ( RRMS ). Despite an established effect on heart rate, the effect of fingolimod on cardiac repolarization is not completely known. Methods Twenty‐seven patients with RRMS underwent 24‐hr ambulatory ECG before fingolimod (baseline), at the day of fingolimod initiation (1D) and after three‐month treatment (3M). The mean values of RR ‐interval as well as QT ‐interval corrected by Bazzet's ( QT cBaz) and Fridericia's ( QT cFri) formula were compared between baseline, 1D, and 3M over 24‐hr period as well as at daytime and nighttime. Results QT cBaz over 24‐hr was shorter at 1D (414 ± 20 ms, p < .001) and at 3M (414 ± 20 ms, p < .001) than at baseline (418 ± 20 ms). In contrast, QT cFri over 24‐hr was longer at 1D (410 ± 19 ms, p < .001) but similar at 3M (406 ± 19 ms, p = .355) compared to baseline (407 ± 19 ms). Daytime QT cBaz was shorter at 1D ( p < .001) and at 3M ( p = .007), whereas daytime QT cFri was longer at 1D ( p < .05) but similar at 3M ( p = ns) compared to baseline. During the night, changes were observed neither in QT cBaz nor in QT cFri between baseline, 1D, and 3M. Conclusions Changes in cardiac repolarization after fingolimod initiation were mild and occurred at daytime. Ambiguously, QT cBaz demonstrated shortening, whereas QT cFri showed prolongation in cardiac repolarization after fingolimod initiation. The formula applied for QT ‐interval correction needs to be taken carefully into account as evaluating pharmacovigilance issues related to fingolimod.