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Results: Among the patients who were and were not withdrawn from antidepressants treatment, the median frequency of baseline weekly cataplexy was similar (17.5 vs. 14.0, respectively).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Conclusions: Patients gradually withdrawn from antidepressants experienced a significant increase in cataplexy, but eventually returned to their baseline frequency, comparable to previously untreated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.