What the label lists and what reports show
Calcium oxybate, magnesium oxybate, potassium oxybate and sodium oxybate side effects
Calcium oxybate, magnesium oxybate, potassium oxybate and sodium oxybate's FDA label: “Most common adverse reactions in adults with narcolepsy or IH (≥5%) were nausea, headache, dizziness, anxiety, insomnia, decreased appetite, hyperhidrosis, vomiting, diarrhea, dry mouth, parasomnia, somnolence, fatigue, and tremor ( 6.1 ).” FAERS holds 8,562 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is product administration interrupted (1,528 reports).
- No generic listed
- Boxed warning
- DEA Schedule III
Check it at the source: the calcium oxybate, magnesium oxybate, potassium oxybate and sodium oxybate FDA label on DailyMed (effective July 1, 2025, Jazz Pharmaceuticals, Inc.); the FDA FAERS public dashboard.
What does the patient leaflet say about side effects?
From the patient leaflet: What are the possible side effects of XYWAV?XYWAV can cause serious side effects, including: • See “What is the most important information I should know about XYWAV?” • breathing problems, including: o slower breathing. o trouble breathing. o short periods of not breathing while sleeping (sleep apnea). People who already have breathing or lung problems have a higher chance of having breathing problems when they take XYWAV. • mental health problems, including: o confusion o seeing or hearing things that are not real (hallucinations) o unusual or disturbing thoughts (abnormal thinking) o feeling anxious or upset o depression o thoughts of killing yourself or trying to kill yourself o increased tiredness o feelings of guilt or worthlessness o difficulty concentrating Call your doctor right away if you have or your child has symptoms of mental health problems, or a change in weight or appetite. • sleepwalking. […]
Source: FDA drug label, Jazz Pharmaceuticals, Inc., effective July 1, 2025 (SPL set 1e0ae43a-037f-42af-8e23-a0e51d75abe8), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsMost common adverse reactions in adults with narcolepsy or IH (≥5%) were nausea, headache, dizziness, anxiety, insomnia, decreased appetite, hyperhidrosis, vomiting, diarrhea, dry mouth, parasomnia, somnolence, fatigue, and tremor ( 6.1 ).
Table 5: Adverse Reactions Occurring in ≥2% of Patients Treated with XYWAV in the Open-Label Titration and Stable Dose Periods in Study 2
| Adverse Reaction | * includes anxiety, nervousness, and panic attack † includes middle insomnia, initial… Open-Label Titration Period + Stable Dose Period (up to 16 weeks) (N=154) % |
|---|---|
| Nausea | 21 |
| Headache | 16 |
| Anxiety | 12 |
| Dizziness | 12 |
| Insomnia | 9 |
| Hyperhidrosis | 8 |
| Decreased appetite | 8 |
| Vomiting | 7 |
| Dry mouth | 6 |
| Diarrhea | 5 |
| Fatigue | 5 |
| Somnolence | 5 |
| Tremor | 5 |
| Parasomnia | 5 |
| Balance disorder ♠ | 3 |
| Muscle spasms | 3 |
| Fall | 3 |
| Paresthesia | 3 |
| Snoring | 3 |
| Weight decreased | 3 |
| Bruxism | 3 |
| Confusional state | 3 |
| Depressed mood | 3 |
| Feeling drunk | 3 |
| Irritability | 3 |
Rows and numbers as the label prints them, under its own column headings (the first rows of a longer table where it runs on). A reaction in a trial table is not necessarily caused by the medicine, and trials differ from everyday use.
From the label: adverse reactions, continuedThe following clinically significant adverse reactions appear in other sections of the labeling: • CNS depression [see Warnings and Precautions ( 5.1 )] • Abuse and Misuse [see Warnings and Precautions ( 5.2 )] • Respiratory Depression and Sleep-Disordered Breathing [see Warnings and Precautions ( 5.4 )] • Depression and Suicidality [see Warnings and Precautions ( 5.5 )] • Other Behavioral or Psychiatric Adverse Reactions [see Warnings and Precautions ( 5.6 )] • Parasomnias [see Warnings and Precautions ( 5.7 )] Most common adverse reactions in adults with narcolepsy or IH (≥5%) were nausea, headache, dizziness, anxiety, insomnia, decreased appetite, hyperhidrosis, vomiting, diarrhea, dry mouth, parasomnia, somnolence, fatigue, and tremor ( 6.1 ). In a pediatric study with sodium oxybate (same active moiety as XYWAV), the most common adverse reactions (≥5%) were nausea, enuresis, vomiting, headache, weight decreased, decreased appetite, dizziness, and sleepwalking ( 6.1 ). To report SUSPECTED ADVERSE REACTIONS, contact Jazz Pharmaceuticals, Inc. at 1-800-520-5568, or FDA at 1-800-FDA-1088 or www.fda.gov/Medwatch. …
Source: FDA drug label, Jazz Pharmaceuticals, Inc., effective July 1, 2025 (SPL set 1e0ae43a-037f-42af-8e23-a0e51d75abe8), via openFDA; the full label on DailyMed
What do FAERS reports show?
8,562 reports list calcium oxybate, magnesium oxybate, potassium oxybate and sodium oxybate among the medicines taken, each a report of something that happened, not proof the medicine caused it; 81 are coded as a death and 1,601 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Reports rose sharply in 2024 (2,063, against a median of 11 a year): FAERS counts follow reporting, which news, litigation and label changes can drive, not how often a reaction happens. Of the 19 reactions below, 11 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
Reports received each year
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Calcium oxybate, magnesium oxybate, potassium oxybate and sodium oxybate: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions