65% of Patients Discontinue Therapy Baclofen Within a Year in Study

About 10%-20% of people with multiple sclerosis (MS) receive baclofen to control their spasticity, but up to half of patients stop the medication in the first six months, a large Swedish population-based study shows.

The high rates of discontinuation suggest baclofen has “a low success rate of treating spasticity and demonstrates an unmet need of tolerated, effective spasticity treatments,” researchers wrote.

The study, “Spasticity treatment patterns among people with multiple sclerosis: a Swedish cohort study,” was published in the Journal of Neurology, Neurosurgery & Psychiatry.

Spasticity — when muscles are abnormally stiff and prone to spasms — is one of the most common symptoms of MS. It most often affects men, older patients, and those with progressive forms of MS, including primary progressive MS (PPMS) and secondary progressive MS (SPMS).

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Baclofen, a muscle relaxant, is the only first-line treatment approved for spasticity in Sweden. However, studies of spasticity in people with MS remain scarce, and there are currently no real-world reports that assessed treatment patterns. Moreover, it is unclear which factors increase the need for spasticity treatment.

“Understanding how and why spasticity manifests frequently among pwMS [people with MS] will help identify possible preventative strategies and earlier treatment possibilities,” the researchers wrote.

A team led by researchers at the Karolinska Institute in Sweden aimed to investigate the factors linked with the need for spasticity treatment among people with MS who participated in Swedish registers between 2004 and 2014.

The researchers noticed that half of patients (50%) discontinued baclofen in the first six months, and 90% discontinued within two years. Accounting both patients with incident MS and prevalent MS, 65% discontinued baclofen within the first year.

However, patients with higher expanded disability status scale (EDSS) — indicative of greater disability — stayed with baclofen treatment for longer.

A similar trend of discontinuation was also observed for other treatments used to manage spasticity, namely gabapentin and diazepam. Gabapentin was discontinued by 75% of patients after one year and diazepam was almost completely discontinued after six months.

“High rates of discontinuation of treatment highlights an unmet need of tolerable and effective spasticity treatment alternatives,” the researchers wrote.

Two groups were analyzed in study

Participants were categorized into two groups: those diagnosed prior to July 1, 2005, who were said to have prevalent MS; and patients diagnosed after that date who had incident MS. In total, 1,826 patients with incident MS and 3,519 with permanent MS were included in the analysis.

Patients with incident MS had a median age of 45.5 years and were followed for a median 6.4 years. Those with prevalent MS had a median of 55.7 years and their median follow-up was 8.5 years.

Baclofen was more commonly prescribed to people with prevalent MS (17.8%) compared with incident MS (10.3%). In both groups, patients given baclofen were older at disease onset and diagnosis.

Patients with incident MS were prescribed with baclofen earlier — within the first six months of MS diagnosis — compared with those with prevalent MS, who received the medication within three years of diagnosis.

Statistical analyses demonstrated men and people with progressive forms of MS had a greater risk of being prescribed with baclofen. There was also a trend toward less use of baclofen with longer disease duration.

Also, higher scores on the expanded disability status scale (EDSS) — indicative of greater disability — at the start of the follow-up (baseline) were associated with baclofen treatment, even after controlling for MS features.

The researchers estimated EDSS and disease duration at baseline were the strongest predictor of baclofen use. However, these results were influenced by patient’s age, with MS patients generally requiring spasticity treatment at younger ages.

“Individuals with the same EDSS score, but at different ages had differences in the magnitude of the association with baclofen initiation,” the researchers wrote.

Additionally, participants with other diseases showed a higher risk for spasticity treatment. Depression, seizures, and Parkinson’s disease were the diseases most associated with a higher baclofen use.

Overall, these findings highlight “the importance of informed treatment options and better understanding of spasticity in general among patients with MS,” they concluded.