Suboptimal response for first line treatment of multiple sclerosis (MS) is one of the main challenges for real clinical practice. Presence of subthreshold activity suggests the possibility of switching to the second line of therapy, however, this is not always possible due to various reasons. Suboptimal response also could lead to increasing of patient’s reactive depression.
To define the possibility of using SSRI (duloxetine or fluoxetine) for patients with suboptimal response on first-line injectable disease modifying therapy (DMT) to optimize response rate.
Clinical evaluation (EDSS, relapses), depression (Beck), MRI (T2&T1). Statistical analysis (nonparametric) – Wilkoxon test, Sign test. Inclusion criteria: 1) relapsing-remitting MS, 2) interferon beta (IFN) or glatiramer acetate (GA) during last 12 months, 3) suboptimal response for therapy defined by modified Rio Score (1 relapse during previous year without MRI activity OR +4-6 T2 lesions on MRI during previous year), 4) mild or moderate depression. Exclusion criteria: 1) progressive MS, 2) nonresponse defined by modified Rio Score and indication for switch to 2nd line, 3) severe depression, 4) severe comorbidity. Study design: visit 1 – baseline (EDSS, previous year relapses, MRI, depression scale), starting SSRI (duloxetine or fluoxetine); visit 2 – 1 year on SSRI + previous DMT (EDSS, previous year relapses, MRI, depression scale).
Seventy patients (56 females), relapsing-remitting MS, age – 35,2 years [Q1:Q3; 28:42], duration of disease – 4,2 years [2:10], EDSS at visit 0 – 3.0 [2.4:3.6], DMT (GA–20, IFNb1b–30, IFNb1a–20) who met criteria at visit 1. Baseline relapse rate was 0.65 [95% confidence interval (CI) 0.61-0.70], dynamics of T2 lesion load during previous year +3.57 lesion [95%CI 2.6-4.8], EDSS dynamics during previous year - +0.27 [95%CI 0.24-0.31]. After 1 year of combined therapy (DMT+SSRI) relapse rate significantly decreased - 0.2 (T=180, p<0.001), no significant increase of EDSS level – minus 0.36 points. MRI activity also significantly decrease: numbers of new or newly enlarging T2 lesions were significantly reduced compared with the previous year: T2 lesion load increase only by 0.4 [95%CI 0.3-0.5] (T=51, p<0.001).
Adding SSRI (duloxetine or fluoxetine) to standard first line DMT for patients with suboptimal response could improve the response to the main DMT without switching to 2nd line.