How to Take Xywav for Narcolepsy
Xywav is administered as a liquid in two equally divided doses at night: take the first dose at bedtime and the second dose 2.5-4 hours later. 1
Dosing Administration Protocol
Nighttime Dosing Schedule
- Prepare both doses before bedtime by dividing the total nightly dose into two equal portions 1
- Take the first dose immediately at bedtime while sitting up in bed 1
- Set an alarm for 2.5-4 hours later to take the second dose 1
- Remain in bed after taking each dose, as Xywav causes rapid onset of sleep 1
Gram-per-Gram Transition from Xyrem
- If switching from high-sodium oxybate (Xyrem), transition gram-per-gram to Xywav without dose adjustment 2
- Most patients (93%) report this transition is "easy" with minimal modifications needed 2
- The same total nightly dose is maintained (typically 6-9 g/night in adults) 3
Critical Safety Requirements
Black Box Warnings and Restrictions
- Xywav is only available through the FDA Risk Evaluation Mitigation Strategy (REMS) program using certified pharmacies due to its Schedule III controlled substance status 4, 1
- This medication carries an FDA black box warning for respiratory depression as a central nervous system depressant 4, 1
- Never combine with alcohol or other sedating medications due to severe risk of respiratory depression, decreased consciousness, coma, and death 4, 1
Contraindications and Cautions
- Use with extreme caution in patients with any respiratory conditions including sleep-disordered breathing 4, 1
- Avoid in pregnant or breastfeeding women as animal data suggests fetal harm, though human data are insufficient 4, 1
- Exercise extreme caution when combining with amphetamines due to opposing CNS effects requiring careful dose titration and cardiovascular monitoring 1
Common Adverse Effects to Monitor
Frequently reported side effects include: 4, 1
- Nausea and dizziness
- Nocturnal enuresis (bedwetting)
- Headache
- Chest discomfort
- Sleep disturbances and confusion
Advantages of Xywav Over High-Sodium Formulations
- Xywav contains 92% less sodium than Xyrem (1100-1640 mg less sodium per night at standard adult doses) 3, 2
- The FDA recognizes this lower sodium content as clinically meaningful in reducing cardiovascular morbidity in the narcolepsy population 2
- 79% of patients prefer Xywav over Xyrem, most commonly due to the lower sodium content 2
- Effectiveness is maintained when switching from Xyrem to Xywav 2
Alternative Once-Nightly Formulation
- Once-nightly sodium oxybate (Lumryz/FT218) is now FDA-approved, eliminating the need for a middle-of-the-night dose 5, 6
- Both once-nightly and twice-nightly regimens similarly improve disrupted nighttime sleep symptoms 6
- The once-nightly formulation contains equal sodium to Xyrem (not reduced like Xywav) 6