Sodium oxybate

How it works

It is a central nervous system depressant acting at GABA-B and GHB receptors, consolidating night-time sleep architecture which reduces daytime sleepiness and cataplexy.

Prescribing in practice

• It is a potent CNS depressant with a high risk of respiratory depression and abuse, and must never be combined with alcohol, opioids or other sedating agents.
• It carries a substantial sodium load, which is relevant in heart failure, hypertension and renal impairment, and a low-sodium oxybate formulation exists.
• Doses are taken at night in two divided portions, the first at bedtime and the second a few hours later, with the patient remaining in bed.

Monitoring

Monitor for respiratory depression, excessive sedation, mood or behavioural changes, sleep-related breathing disorders and signs of dependence, alongside blood pressure given the sodium content.

Counselling the patient

• Never drink alcohol or take other sedatives with this medicine; doing so can dangerously slow your breathing.
• Prepare both night-time doses in advance, take them while in bed, and do not drive until you know how it affects you.
• Keep it securely stored, as it has potential for misuse and diversion.

Evidence & guidelines

Randomised controlled trials demonstrate reduced cataplexy and daytime sleepiness in narcolepsy, and it is supplied within a controlled distribution framework reflecting MHRA and SPC safety warnings.