Polypharmacy Burden in Patients with Relapsing-Remitting Multiple Sclerosis

Patients with relapsing-remitting multiple sclerosis (RRMS), particularly those who are more severely disabled with comorbidities, may have a high burden of polypharmacy, according to a new study published in PLOS ONE.

Polypharmacy can have potentially negative effects if ignored, including increased rehospitalizations, serious drug interactions, lack of adherence, cognitive decline, rising costs, and adverse effects. Due to the chronic nature of the disease, patients with MS are treated with long-term disease-modifying drugs (DMDs) in combination with symptomatic therapies to help improve overall quality of life. In addition, patients may also need treatment for secondary illnesses.

For the study, the researchers aimed to examine the frequency of polypharmacy in 145 patients with RRMS in an outpatient setting and determine potential influencing factors that contribute to polypharmacy. They also evaluated the differences in medications between MS patients with secondary illnesses (PwSI) and without secondary illnesses, between men and women, and between patients with and without polypharmacy. For the study, polypharmacy was defined as the use of 5 or more medications.

According to the findings, polypharmacy was identified in approximately 30% of all patients, based on the definition of polypharmacy including the full spectrum of medications. When taking only long-term medications into account, the polypharmacy rate was lower (20.7%). The majority of patients (89.7%) examined took drugs administered orally.

The proportion of polypharmacy among patients with secondary illnesses was approximately 4 times higher than among those without secondary illnesses, at 46.8% versus 11.8%, respectively, according to the study. The researchers noted that patients with secondary illnesses were significantly older and twice as likely to be retired, which may be attributable to the growing number of comorbidities and associated therapies with increasing age.

“The risk of polypharmacy is strongly increased in PwSI, which implies a higher risk of drug interactions and side effects,” the researchers wrote in the study. “In this patient group, therefore, a well thought-out medication management is especially necessary.”

Higher Expanded Disability Status Scale (EDSS) scores were linked to a higher likelihood of polypharmacy, with the risk of polypharmacy increasing by 44% for every 1 step on the EDSS. These patients were also more likely to take symptomatic drugs. Overall, higher EDSS scores and the presence of comorbidities were significantly associated with a higher risk of polypharmacy (EDSS score with p = 0.029 and OR = 1.440; comorbidities with p<0.001 and OR = 6.293), according to the study data.

DMDs were the most frequently used medication, followed by dietary supplements, the researchers found. They noted that providers should account for prescription-free supplements when managing patients with MS to avoid the risk of potential drug interactions and adverse effects.

The study also determined that the most prevalent comorbidities among these patients were thyroid diseases, hypertonia, gastrointestinal diseases, and deficiency symptoms. Although most of the drugs taken for these comorbidities are administered orally, some of them may be treated with combination therapies consisting of 2 or more drugs that could have different administrations.

“RRMS patients with secondary illnesses are particularly affected by polypharmacy,” the researchers concluded. “Further evidence is needed on how polypharmacy poses an issue in the management of MS and this demands a prospective study of side effects, drug interactions, and adherence problems.”

Reference

Frahm N, Hecker M, Zetti UK. Polypharmacy in outpatients with relapsing-remitting multiple sclerosis: A single-center study. PLOS ONE. 2019. https://doi.org/10.1371/journal.pone.0211120