Weight loss in narcolepsy patients treated with sodium oxybate.

INTRODUCTION: Narcolepsy is often associated with increased body weight. Sodium oxybate has efficacy in many narcolepsy symptoms. The purpose of this study was to evaluate the effects of sodium oxybate on weight in patients with narcolepsy. METHODS: Charts from three centers of all patients with narcolepsy who had been using sodium oxybate for at least 3 months were reviewed. Patients in whom anti-cataplexy medications were added or withdrawn or wake-promoting medications added after the start of sodium oxybate were excluded from further analysis. In the remainder, pre-sodium oxybate and, most recently, on-sodium oxybate weights were compared using Student's t-tests. Sodium oxybate dose and duration of therapy were also noted. RESULTS: A total of 54 patients meeting inclusion criteria were identified. Of these 54, 33 (61%) were women; the mean age was 48.3 years. The mean dose of sodium oxybate was 6.9g/night and the duration of therapy was 25 months. The mean pre-sodium oxybate weight was 78.3 (+/-15.7)kg. The most recent on-sodium oxybate weight was 74.9 (+/-15.1, p=0.003). The average weight loss was 3.4kg, whereas the maximum was 30.9kg. CONCLUSIONS: This study suggests that treatment of patients with narcolepsy with sodium oxybate can result in weight loss.

Exacerbation of cataplexy following gradual withdrawal of antidepressants: manifestation of probable protracted rebound cataplexy.

BACKGROUND: A double-blind, placebo-controlled sodium oxybate trial provided a unique opportunity to compare changes in cataplexy following gradual withdrawal from antidepressants in narcolepsy patients. METHODS: Of 228 enrolled patients, 71 discontinued antidepressant therapy. Data from 57 patients were available for analysis: 37 patients discontinued tricyclic antidepressants (TCAs) and 20 discontinued selective serotonin reuptake inhibitors (SSRIs). The trial included a 21-day withdrawal phase followed by 18-day washout and 14-day single-blind treatment phases. Two additional weeks were permitted for withdrawal from fluoxetine due to its long half-life. Weekly cataplexy attacks were recorded throughout the trial. No historical data on the frequency of cataplexy prior to treatment with antidepressants was available. RESULTS: Among the patients who were and were not withdrawn from antidepressants treatment, the median frequency of baseline weekly cataplexy was similar (17.5 vs. 14.0, respectively). As expected, significant between-group differences emerged by the end of the washout period (52.04 vs. 15.25, respectively; p<0.05); however, the frequency of cataplexy events became similar again by the end of the trial (16.5 vs. 17.5, respectively). CONCLUSIONS: Patients gradually withdrawn from antidepressants experienced a significant increase in cataplexy, but eventually returned to their baseline frequency, comparable to previously untreated control patients. Compared to SSRIs, discontinuation from TCAs was associated with a greater increase in cataplexy attacks.