VANCOUVER, BC—For patients with relapsing-remitting multiple sclerosis (RRMS), concomitant use of selective serotonin reuptake inhibitors (SSRIs) and fingolimod was not found to affect cardiac outcomes related to initiation of fingolimod. These study findings were presented at the 68th AAN Annual Meeting by Bruce Hughes, MD, Mercy Ruan Neuroscience Center, Des Moines, IA.

Previous studies have shown that fingolimod is known to cause transient bradycardia in patients. SSRIs (especially citalopram and escitalopram) are commonly used to treat depression and anxiety in patients with MS, and may cause QT interval prolongation. Dr. Hughes and coauthors performed a pooled analysis to investigate the first-dose effects of fingolimod on cardiac outcomes in patients receiving concomitant SSRIs on Day 1. They used data from Phase 4 real-world studies: the 6-month EPOC trial and the 12-month PREFERMS trial. Data from these previous trials supported that symptomatic bradycardia and atrioventricular block were uncommon and typically required no intervention; most study patients were discharged from first-dose monitoring 6 hours after their dose was administered.

The researchers identified that 313 of the total 1,420 patients included in the analysis received an SSRI on Day 1 of which 167 patients received citalopram or escitalopram (C/E). 

Results showed the lowest mean sitting heart rate in the SSRI and C/E subgroups was obtained by 5 hours post-dose (mean reduction from baseline  -7.2bpm and -7.6bpm) for SSRI and C/E arms, respectively. This finding was consistent with the -7.8bpm reduction observed in the pooled population. Similarly, the lowest systolic blood pressure was reached at 4 hours post-dose in the SSRI and C/E subgroups (mean reduction from baseline -3.2mmHg and -4.1mmHg, respectively).

All rates began to recover after the 6th hour post-dose. Most patients were discharged at 6 hours (overall, 94.9%; SSRI, 97.1%; C/E, 95.8%) and few required monitoring afterward (overall, 4.4%; SSRI, 2.6%; C/E; 3.6%). In the pooled population, hospitalization was required in 0.2% of patients, and 0.7% had symptomatic bradycardia. 

“Our results show that concomitant use of SSRIs does not affect cardiac outcomes associated with fingolimod initiation,” said Dr. Hughes. “These real-world study findings are consistent with the controlled fingolimod trials.”