Off-label treatment of severe childhood narcolepsy-cataplexy with sodium oxybate

Abstract

Study Objectives: To evaluate the efficacy and side-effect profile of off-label sodium oxybate (gamma hydroxy butyrate) therapy in severe childhood narcolepsy-cataplexy. Design: Retrospective; chart review. Setting: A multidisciplinary tertiary sleep center. Patients: A group of eight children with severe narcolepsy-cataplexy diagnosed on the basis of clinical history, nocturnal polysomnography and the multiple sleep latency test were studied. A modified Epworth Sleepiness Scale and an arbitrary cataplexy severity scale (1=minimal weakness, 2= voluntarily preventable falls, 3=falls to the ground) were utilized. Interventions: Sodium oxybate therapy; concurrent medications were maintained. Measurements and Results: Before sodium oxybate therapy, all subjects had suboptimally controlled sleepiness and cataplexy. Following treatment with sodium oxybate, 7/8 subjects (88%) improved. Cataplexy frequency decreased from a median of 38.5 to 4.5/week (p = 0.0078). Cataplexy severity decreased from 2.75 to 1.75 (p = 0.06). The Epworth Sleepiness Scores improved from a median of 19 to 12.5 (p = 0.02). Suicidal ideation, dissociative episodes, tremor and constipation occurred in one subject each and terminal insomnia in two. Three of the 8 (38%) discontinued therapy. Two stopped the drug owing to side effects and one due to problems with postal delivery of the medication. Conclusions: This is the first report on sodium oxybate therapy in childhood narcolepsy-cataplexy. Our finding of improvement in cataplexy and sleepiness suggests that this medication is effective in treating severe childhood narcolepsy-cataplexy.