Switching from injectable to other Disease Modifying Therapies may improve sexual dysfunction in people with Multiple Sclerosis

Multiple Sclerosis (MS) a central nervous system autoimmune disorder, mainly affecting young adults and more prevalent among women, can lead to sexual dysfunction (SD) among both males and females with MS. Female sexual dysfunction can be defined as dyspareunia, a lack of sexual desire, disorders in the arousal and orgasm phases, and sexual pain disorders. The purpose of this study is to investigate the changes in sexual function among females with MS whose treatment was switched from first-line injectable medications to other agents after a six-month duration. And assess the changes in all three domains of SD. In this longitudinal study females diagnosed with MS, aged between 18 and 50 years old, and were candidates for switching their treatment from interferon beta-1a (intra-muscular and subcutaneous), and Glatiramer Acetate (GA), to Fingolimod, Dimethyl Fumarate (DMF), or Natalizumab (NTZ) due to patients' convenience and tolerability and adverse events were included. "Multiple Sclerosis Intimacy and Sexuality Questionnaire-19" was used to evaluate the SD changes before and six months after the new treatment initiation. Statistical analysis was conducted using SPSS V.24 software. Histograms and the Shapiro-Wilk test were used to assess the normality of the variables; due to the non-normal distribution of quantitative variables (except for age), the Wilcoxon signed-rank test was used to compare the scores, before and six months after the medication change. The level of significance was considered less than 0.05. Out of 107 female participants (average age: 35.09 ± 5.61), The mean of overall MSISQ-19 scores, before and six months after the medication change were not significant (p-value = 0.091). However, considering the subdomains, the medication changes only affected the tertiary subdomain of MSISQ-19 (p-value = 0.017). Still, the scores of other subdomains did not change significantly (p-value = 0.761 for primary SD and 0.479 for secondary SD). Also, there wasn't any significant difference between EDSS before and after the medication change (p-value = 0.461). To our knowledge, this was the first study, assessing the effect of MS medication change on the improvement of SD among patients. According to the results of the presented cross-sectional study, we found that during a six-month period, the tertiary subdomain of MSISQ-19 symptoms improved significantly, while the changes in other SD domains were not significant.