Lower-Sodium Oxybate Maintains Narcolepsy Symptom Relief, Reduces Dizziness and Sweating, and Is Preferred by Patients

Interim data analysis from the TENOR trial (NCT04803786) shows people with narcolepsy who switched from sodium oxybate (Xyrem; Jazz Pharmaceuticals, Philadelphia, PA) to lower-sodium oxybate (Xywav; Jazz Pharmaceuticals) maintained symptomatic relief. Lower-sodium oxybate is approved by the Food and Drug Administration (FDA) and is expected to reduce cardiovascular morbidity in many for whom oxybate is indicated for treatment of narcolepsy.

Decreases in the proportion of participants with excessive sweating (from 40.5% to 26.6%) and dizziness (27.4% to 13.9%) were seen 1 week after switching to lower-sodium oxybate. 

Almost all participants (92%, n=85) selected "long-term health/lower sodium content)" as a reason for making this switch. Other reasons selected included physician recommendation (47.1%), avoiding current cardiovascular issues (38.8%), avoiding side effects (30.6%), and to improve symptom control (17.6%). Participants could select more than 1 reason and 14.1% selected another reason in addition to these.

Concomitant medications taken by participants in TENOR at baseline including wake-promoting agents (47.1%), amphetamine stimulants (35.3%), selective serotonin/norepinephrine reuptake inhibitors (32.9%), methylphenidate stimulants (9.4%), and other agents (5.9%).

Similarly, in the smaller SEGUE study (NCT04794491), participants (n=21) had baseline measurements while taking sodium oxybate for2 weeks and then switched to lower-sodium oxybate. After 6 weeks, ESS scores were similar (mean change -0.6±2.0, median change 0.0 [range -5.0 to 3.0]). Participants in SEGUE were able to maintain concomitant medications, but which medications they took were not reported. 

After switching and taking lower-sodium oxybate for 6 weeks, 57.1% of participants in SEGUE reported improved narcolepsy and 42.9% reported no change. Only 9.5% of participants reported that making the switch was difficult. In a forced preference questionnaire, 85.7% of participants said they preferred lower-sodium oxybate.

The American Academy of Sleep Medicine strongly recommends sodium oxybate as effective for improving cataplexy and excessive daytime sleepiness in narcolepsy. Lower-sodium oxybate contains the same active moiety with 92% less sodium.