Disease-modifying treatments for patients with multiple sclerosis in Spain

Multiple sclerosis is a chronic demyelinating disease of the central nervous system and long-term disabling. Different disease-modifying treatments are available. These patients, despite being generally young, have high comorbidity and risk of polymedication due to their complex symptomatology and disability.

To determine the type of disease-modifying treatment in patients seen in Spanish hospital pharmacy departments.

To determine concomitant treatments, determine the prevalence of polypharmacy, identify the prevalence of interactions and analyse pharmacotherapeutic complexity.

Observational, cross-sectional, multicentre study. All patients with a diagnosis of multiple sclerosis and active disease-modifying treatment who were seen in outpatient clinics or day hospitals during the second week of February 2021 were included. Modifying treatment, comorbidities and concomitant treatments were collected to determine multimorbidity pattern, polypharmacy, pharmacotherapeutic complexity (Medication Regimen Complexity Index) and drug-drug interactions.

1,407 patients from 57 centres in 15 autonomous communities were included. The most frequent form of disease presentation was the relapsing remitting form (89.3%). The most prescribed disease-modifying treatment was dimethyl fumarate (19.1%), followed by teriflunomide (14.0%). Of the parenteral disease-modifying treatments, the two most prescribed were glatiramer acetate and natalizumab with 11.1% and 10.8%. 24.7% of the patients had one comorbidity and 39.8% had at least 2 comorbidities. 13.3% belonged to at least one of the defined patterns of multimorbidity and 16.5% belonged to 2 or more patterns. The concomitant treatments prescribed were psychotropic drugs (35.5%); antiepileptic drugs (13.9%) and antihypertensive drugs and drugs for cardiovascular pathologies (12.4%). The presence of polypharmacy was 32.7% and extreme polypharmacy 8.1%. The prevalence of interactions was 14.8%. Median pharmacotherapeutic complexity was 8.0 (IQR: 3.3 -- 15.0).

We have described the disease-modifying treatment of patients with multiple sclerosis seen in Spanish pharmacy services and characterised concomitant treatments, the prevalence of polypharmacy, interactions, and their complexity.