Study Provides Insights Into Narcolepsy Treatment and Health Care Utilization Impact in Sweden

Narcolepsy, a neurological disorder affecting rapid eye movement (REM) sleep, is a complex disease associated with many comorbidities that can affect patients’ quality of life and have socioeconomic consequences. A recent study published in Acta Neurologica Scandinavica assessed the pharmacological treatments and health care utilization of patients with narcolepsy in Sweden, creating a framework for future analyses and providing insights into health care cost trends associated with narcolepsy.

Narcolepsy is characterized by symptoms including daytime sleepiness, disrupted nighttime sleep with nightmares, hypnagogic hallucinations, sleep paralysis, and cataplexy — a partial or total loss of muscle tone that is often brought on by strong emotion. There are 2 types of narcolepsy. Type 1 is caused by an orexin deficiency and includes cataplexy, while type 2 is more common and does not include cataplexy. Narcolepsy is also associated with comorbidities including obesity, high cholesterol, glucose intolerance, psychiatric disorders, digestive issues, heart and upper-respiratory issues, and more.

Pharmaceutical treatment for narcolepsy has advanced in recent years, but treatment was formerly symptomatic, or limited to medications to mitigate daytime sleepiness or cataplexy, or both. Combination treatments are common, the authors noted. “It is, however, important to underline that the borders between specific effects are not clear-cut.When a patient receives an effective treatment against daytime sleepiness, this may reduce the tendency to develop cataplexy as well,” they wrote.

A stimulant to alleviate daytime sleepiness combined with an antidepressant to work against cataplexy is one common example. Sodium oxybate, a drug that relieves daytime sleepiness, cataplexy, and night-time sleep disturbance, has serious side effects ranging from respiratory issues to depression and is not reimbursed by the state in Sweden. Study authors also aimed to compare heath care utilization between patients receiving standard treatment versus those taking sodium oxybate.

The study included 2508 patients diagnosed with and treated for narcolepsy. Data from the Swedish National Patient Registry (NPR), the Swedish Prescribed Drug Register, and the National Cause of Death Register were used in the study. Pharmacological data from 2005-2017 and health care utilization data from 1997-2016 were pulled.

Mean age at diagnosis was 34 years, and 56.7% of the cohort were women. The 2508 patients used 3817 pharmaceutical treatments for narcolepsy in total. Modafinil, a stimulant to counteract daytime sleepiness, was the most common medication in this cohort, with 1202 (47.9%) of patients prescribed it. This was followed by methylphenidate (33.8%) and amphetamine (26.2%), which are also stimulants. A total of 23.6% of patients used an antidepressant.

Study authors also noted that women more often started modafinil, methylphenidate, amphetamine, and antidepressants than men. About 10% of patients overall used sodium oxybate, which was prescribed to men and women at similar rates. Younger patients were more likely to be given sodium oxybate and methylphenidate compared with older patients. A total of 16.5% of patients in the study group did not receive any of the listed narcolepsy treatments.

Health care utilization data were available for 2493 patients in the study cohort. Patients diagnosed with narcolepsy had an average of 0.2 inpatient and 2.6 outpatient visits in the 12 months before index date. There were data for 2408 patients’ health care utilization within 12 months after index date. On average, narcolepsy patients had 0.3 all-cause inpatient visits and 3.5 all-cause outpatient visits. Patients prescribed sodium oxybate (n = 238) had 0.1 inpatient visits on average and 5.6 outpatient visits.

“This may indicate that patients treated with sodium oxybate have more severe symptomatology or may have been treated by a more complex pharmacotherapy,” study authors wrote, noting that sodium oxybate is titrated carefully to allow observation for side effects and therefore may require more visits.

The study is limited by its reliance on NPR data, which does not include data from primary care and may underestimate actual prevalence, the authors noted. There also may be mild and untreated cases that go undetected.

“This study provides a framework for evaluation of narcolepsy treatment and health care utilization in Sweden,” the authors concluded. “Further research is needed to develop the results from the current study and to give a full picture of the economic and social implications.”

Reference

Gauffin H, Fast T, Komkova A, Berntsson S, Boström I, Landtblom A. Narcolepsy treatment in Sweden: an observational study. Acta Neurol Scand. 2022;145(2):185-192. doi:10.1111/ane.13532