XYWAV SIDE EFFECTS

  • Generic Name: calcium, magnesium, potassium, and sodium oxybates oral solution
  • Brand Name: Xywav
  • Drug Class: CNS Depressants
Last updated on MDtodate: 10/04/2022

SIDE EFFECTS

The following clinically significant adverse reactions appear in other sections of the labeling:

  • CNS depression
  • Abuse and Misuse
  • Respiratory Depression and Sleep-Disordered Breathing
  • Depression and Suicidality
  • Other Behavioral or Psychiatric Adverse Reactions
  • Parasomnias

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice.

Adult Patients

The safety of XYWAV was evaluated in a 16-week double-blind placebo-controlled randomized-withdrawal study in patients with narcolepsy with cataplexy (Study 1), which was followed by an open-label extension phase lasting 24 weeks. Study 1 included an open-label titration period (OL OTTP), a stable-dose period (SDP), and a double-blind, placebo-controlled, randomized-withdrawal period (DB RWP). A total of 201 patients, ages 18 to 70 years, received XYWAV at individually titrated doses for 14 weeks, followed by randomization to XYWAV or matching placebo for 2 weeks of treatment. The mean exposure to XYWAV during this study, including titration, the randomized withdrawal period, and the open-label extension, was 151 days. In patients who remained on treatment, adverse reactions tended to occur early and diminish over time.

Adverse Reactions Leading to Treatment Discontinuation

In Study 1, 9 of 201 patients (4%) reported adverse reactions that led to withdrawal from the study (anxiety, decreased appetite, depressed mood, depression, fatigue, headache, irritability, nausea, pain in extremity, parasomnia, somnolence, and vomiting). The most common adverse reaction leading to discontinuation was nausea (1.5%). The majority of adverse reactions leading to discontinuation began during the first few weeks of treatment.

Commonly Observed Adverse Reactions

The most common adverse reactions in Study 1 (incidence ≥ 5% of XYWAV-treated patients) were headache, nausea, dizziness, decreased appetite, parasomnia, diarrhea, hyperhidrosis, anxiety, and vomiting.

Adverse Reactions Occurring at an Incidence of 2% or Greater

Table 3 lists adverse reactions observed in the open-label titration and stable dose periods of Study 1 that occurred at a frequency of 2% or greater in adult patients treated with XYWAV.

Table 3: Adverse Reactions Occurring in ≥2% of Adult Patients Treated with XYWAV in the Open-Label Titration and Stable Dose Periods in Study 1*

Adverse Reaction Open-Label Titration Period + Stable Dose Period
(14 weeks)
(N=201)
%
Headache 20
Nausea 13
Dizziness 10
Decreased appetite 8
Parasomnia 6
Diarrhea 6
Hyperhidrosis 6
Anxiety§ 5
Vomiting 5
Fatigue 4
Dry mouth 4
Depressed mood 4
Enuresis 4
Irritability 3
Paresthesia 3
Depression 3
Tremor 3
Somnolence 2
Muscle spasms 2
*Adverse reactions related to XYWAV were reported less frequently, as an overall incidence, in patients on Xyrem at study entry than in Xyrem-naïve patients.
Includes abnormal dreams, abnormal sleep-related event, rapid eye movements sleep abnormal, sleep paralysis, sleep talking, sleep terror, sleep-related eating disorder, somnambulism
Includes hyperhidrosis and night sweats
§Includes anxiety, agitation, panic attack, tension
Includes fatigue and asthenia

 

Adverse Reactions Observed in Clinical Studies with Xyrem (≥2%), but not in Study 1, and Which May Be Relevant for XYWAV

Pain, feeling drunk, pain in extremity, cataplexy, disturbance in attention, sleep paralysis, and disorientation.

Pediatric Patients (7 Years Of Age And Older)

In the pediatric clinical trial with Xyrem (same active moiety as XYWAV), 104 patients aged 7 to 17 years (37 patients aged 7 to 11 years; 67 patients aged 12 to 17 years) with narcolepsy received Xyrem for up to one year. This study included an open-label safety continuation period in which eligible patients receiived Xyrem for up to an additional 2 years. The median and maximum exposure across the entire study were 371 and 987 days, respectively.

Adverse Reactions Leading to Treatment Discontinuation

In the pediatric clinical trial with Xyrem, 7 of 104 patients reported adverse reactions that led to withdrawal from the study (hallucination, tactile; suicidal ideation; weight decreased; sleep apnea syndrome; affect lability; anger, anxiety, depression; and headache).

Adverse Reactions in the Xyrem Pediatric Clinical Trial

The most common adverse reactions (≥5%) were nausea (20%), enuresis (19%), vomiting (18%), headache (17%), weight decreased (13%), decreased appetite (9%), dizziness (8%), and sleepwalking (6%).

Additional information regarding safety in pediatric patients appears in the following sections:

  • Respiratory Depression and Sleep-Disordered Breathing
  • Depression and Suicidality
  • Other Behavioral or Psychiatric Adverse Reactions
  • Parasomnias

The overall adverse reaction profile of Xyrem in the pediatric clinical trial was similar to that seen in the adult clinical trial program. The safety profile in pediatric patients with XYWAV is expected to be similar to that of adult patients treated with XYWAV and to that of pediatric patients treated with Xyrem.

Postmarketing Experience

The following adverse reactions have been identified during postapproval use of sodium oxybate. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure:

Arthralgia, fall*, fluid retention, hangover, hypersensitivity, hypertension, memory impairment, nocturia, and vision blurred.

*The sudden onset of sleep in patients taking sodium oxybate, including in a standing position or while rising from bed, has led to falls complicated by injuries, in some cases requiring hospitalization.

 

 

SRC: NLM .