Information about Sodium Oxybate
Oxybate is a small, neuroactive molecule (gamma-hydroxybutyrate) that is used to treat catalepse and daytime sleepiness in patients with narcolepsy. Oxybate has been reported to cause serum enzyme elevations during therapy, but has not been implicated in instances of clinically apparent acute liver injury.
Mechanism of action of Sodium Oxybate
Oxybate (ox' i bate) is a simple amino acid-like molecule (sodium 4-hydroxybutyrate) that has mild neuroactivity which acts to induce normal sleep patterns. Its mechanism of action is unclear, but it is a derivative of gamma-aminobutyric acid (GABA) and appears to be an agonist at the GABA-B receptor. In prospective, randomized controlled trials, oxybate was effective in alleviating symptoms of daytime sleepiness and decreasing episodes of cataplexy in patients with narcolepsy.
FDA approval information for Sodium Oxybate
Oxybate was approved for use in the United States in 2002 as therapy for cataplexy in patients with narcolepsy. These indications were broadened in 2005 to include improvement in the quality of nighttime sleep and decrease in daytime sleepiness in patients with narcolepsy. Although evaluated and reported to be partially beneficial in other conditions (fibromyalgia, chronic fatigue), oxybate is not approved for these indications.
DEA controlled substance classification of Sodium Oxybate
In addition, oxybate is a Schedule III agent, indicating that it has a mild-to-moderate potential for abuse and dependence. For these reasons, the availability of oxybate is restricted and it can only be prescribed as a part of a risk evaluation and mitigation strategy (REMS) program.
Dosage and administration for Sodium Oxybate
Oxybate is available as an oral solution in 180 mL bottles of 500 mg/mL under the brand name Xyrem. The recommended starting dose is 4.5 g at nighttime, which can be increased or decreased at two week intervals in increments of 1.5 g, not to exceed 9 g daily.
Side effects of Sodium Oxybate
Common side effects include nausea, dizziness, headaches, mental confusion, paresthesia and enuresis (bed wetting). Uncommon, but potentially severe adverse reactions (usually associated with excessive doses) include hallucinations, mental confusion, abnormal thinking, disturbed sleep and depression. Instances of abuse and dependence as well as withdrawal symptoms have been described, but are rare. Hydroxybutyrate has been used as a “date rape” drug and it has been implicated in rare instances of acute psychosis, traffic accidents and suicidal overdose.
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