Usual Adult Dose for Narcolepsy:
Initial dose: 4.5 g orally per day, divided and given as 2 equal doses of up to 2.25 g/dose
Maintenance dose: The dose may be increased by 1.5 g (OR 0.75 g/dose) orally per night in weekly intervals up to 6 to 9 g/day.
Maximum dose: 9 g/day
Usual Pediatric Dose for Narcolepsy:
7 years and older:
20 to less than 30 kg:
-Initial dose: Up to 2 g orally per day, divided and given as 2 equal doses of up to 1 g/dose
-Maintenance dose: The dose may be increased by 1 g (OR 0.5 g/dose) orally per night at 1 to 2-week intervals up to 6 g/day.
-Maximum dose: 6 g/day
30 to less than 45 kg:
-Initial dose: Up to 3 g orally per day, divided and given as 2 equal doses of up to 1.5 g/dose
-Maintenance dose: The dose may be increased by 1 g (OR 0.5 g/dose) orally per night at 1 to 2-week intervals up to 7.5 g/day.
-Maximum dose: 7.5 g/day
45 kg and greater:
-Initial dose: Up to 4.5 g orally per day, divided and given as 2 equal doses of up to 2.25 g/dose
-Maintenance dose: The dose may be increased by 1.5 g (OR 0.75 g/dose) orally per night at 1 to 2-week intervals up to 9 g/day.
-Maximum dose: 9 g/day
Comments:
-Patients who sleep more than 8 hours/night may be given the first dose at bedtime or after an initial period of sleep.
-Patients weighing less than 20 kg may be given lower initial, maximum, maintenance, and total maximum nightly doses.
-Unequal doses may be required in some patients to attain an optimal response to treatment.
-Both doses should be diluted at the same time at night.
-The first dose should be taken at bedtime and the other dose should be taken between 2.5 to 4 hours after; some may need to set an alarm to awaken to take the second dose.
-Patients should remain in bed after taking each dose.
-If the second dose is missed, patients should skip the dose and should not take this drug until the next night.
 Detailed Xyrem dosage information
What happens if I miss a dose?
Take the medicine as soon as you can, but only during your normal sleeping hours (wait at least 2 hours after eating). Do not take two doses at one time.
What happens if I overdose?
Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. An overdose of sodium oxybate can be fatal.
Overdose symptoms may include sweating, vomiting, severe confusion, loss of balance or coordination, or seizure (convulsions).
