What monitoring should be performed when initiating therapy with Xyrem (sodium oxybate) and Xywav (low‑sodium oxybate)?

Monitoring Requirements for Xyrem and Xywav

Both Xyrem (sodium oxybate) and Xywav (low-sodium oxybate) require close monitoring for respiratory depression, CNS depression, psychiatric symptoms (depression and suicidality), and sleep-disordered breathing, with regular follow-up visits to reassess treatment efficacy and safety throughout the treatment course. 1, 2

Critical Safety Monitoring

Respiratory and CNS Depression Monitoring

• Monitor for respiratory depression and obtundation, particularly during treatment initiation and dose titration, as these are FDA black box warnings for both medications 1, 2
• Assess for signs of profound sedation, syncope, and decreased consciousness at each visit
• Screen for concomitant use of CNS depressants (opioids, benzodiazepines, sedating antidepressants/antipsychotics, alcohol) at every encounter, as combination use dramatically increases respiratory depression risk 2
• If concurrent CNS depressants are required, consider dose reduction or discontinuation of one or more agents, including potentially interrupting oxybate therapy 2

Sleep-Disordered Breathing Assessment

• Evaluate for sleep-disordered breathing including central sleep apnea, which has been reported with sodium oxybate use 1
• Consider polysomnography during follow-up, particularly if new respiratory symptoms emerge 3
• In patients with pre-existing obstructive sleep apnea, ensure continuous positive airway pressure therapy is optimized before and during oxybate treatment 3

Psychiatric Monitoring

Depression and Suicidality

• Monitor for emergent or worsening depression and suicidal ideation at each visit, particularly in pediatric patients where depression and suicidality are documented rare but serious adverse effects 1, 2
• Establish baseline psychiatric status before initiating therapy
• Implement regular screening using standardized depression scales during follow-up

Cognitive and Behavioral Changes

• Assess for confusion, anxiety, and impaired motor/cognitive function 1, 2
• Monitor for parasomnias including sleepwalking episodes, which require evaluation if they occur 2

Adverse Event Monitoring

Common Adverse Effects to Track

Monitor and document at each visit:

• Nausea and vomiting (most common, occurring in 19-34% of patients) 4, 5
• Dizziness (12-17% of patients) 4, 5
• Headache (17-18% of patients) 1
• Nocturnal enuresis (particularly in pediatric patients) 1
• Weight changes (weight loss in pediatric patients) 1

Serious Adverse Effects Requiring Immediate Attention

• Central sleep apnea
• Depression and suicidality
• Seizures (associated with abuse/misuse)
• Chest discomfort
• Sleep disturbances

Special Population Monitoring

Pediatric Patients (≥7 years)

• Monitor growth parameters including weight and appetite 1
• Increased vigilance for enuresis, which is more common in children 1
• Enhanced monitoring for depression and suicidality 1

Hepatic Impairment

• Patients with hepatic impairment require dose reduction to one-half the standard starting dose 2
• More frequent monitoring for adverse effects due to altered drug metabolism 2

Pregnancy and Reproductive-Age Patients

• Assess pregnancy status and reproductive planning before initiating therapy, as animal data suggest fetal harm 1
• The risk-benefit balance differs for pregnant and breastfeeding women 1

Drug Interaction Monitoring

Divalproex Sodium Co-administration

• When initiating divalproex sodium in patients on stable oxybate doses, reduce oxybate dose by at least 20% 2
• Monitor for increased sedation and adjust doses based on clinical response 2

Concomitant Alerting Agents

• Document use of concomitant alerting medications (used by approximately 41% of patients with idiopathic hypersomnia) 5
• Assess for drug-drug interactions and overall symptom control

Follow-Up Schedule and Efficacy Assessment

Regular Reassessment

• Schedule regular follow-up visits to reassess treatment efficacy, as treatment choices may change over time with age and life circumstances 1
• Use standardized scales to track symptom improvement:
  • Epworth Sleepiness Scale for excessive daytime sleepiness
  • Idiopathic Hypersomnia Severity Scale (for IH patients)
  • Patient Global Impression of Change and Severity

Titration Period Monitoring

• During the 2-8 week titration period, monitor closely for adverse effects and symptom response 5
• Adjust doses based on individual clinical response and tolerability, with weekly increases not exceeding specified limits based on patient weight and indication 2

REMS Program Requirements

• Both medications are only available through Risk Evaluation and Mitigation Strategy (REMS) programs using certified pharmacies 1
• Prescribers must be enrolled and certified
• Patients must be enrolled with documentation of safe use
• Prescriber attestation of patient counseling is required 6
• Monitor for and report any suspicion of abuse, misuse, or diversion to the REMS program 6

Common Pitfalls to Avoid

• Failing to screen for concurrent CNS depressant use, particularly alcohol, which is contraindicated 2
• Inadequate monitoring for psychiatric symptoms, especially in vulnerable populations
• Not adjusting doses when initiating divalproex sodium co-therapy
• Overlooking the need for dose reduction in hepatic impairment
• Insufficient patient education about the need to remain in bed after dosing and the risk of abrupt sleep onset 2