Changes in Cataplexy Frequency in a Clinical Trial of Lower-Sodium Oxybate with Taper and Discontinuation of Other Anticataplectic Medications.

People with narcolepsy are often sleepy during the day. They may also have sudden muscle weakness (known as cataplexy). Lower-sodium oxybate (LXB) is a narcolepsy medicine that is similar to sodium oxybate (SXB) but has 92% less sodium. A recent study found that treatment with LXB was better at reducing how often people with narcolepsy had sleepiness and cataplexy than no medicine at all (NCT03030599). This paper is about the first 12 weeks of that study, when all the people taking part in the study first tried LXB to check that they were being given the right amount. In people who only took LXB, cataplexy happened less often over time. Some people were already taking other medicines to treat their cataplexy (such as antidepressants), so they were asked to slowly stop those medicines while taking LXB. In those people, cataplexy happened more often at first as they stopped taking antidepressants and then less often later on. The increase in cataplexy when antidepressants were stopped was smaller in people who switched from SXB to LXB. This study shows that many people getting treatment for narcolepsy can switch to LXB without their cataplexy becoming worse.