Sodium Oxybate in Idiopathic Hypersomnia

"First night after V1: Dose prescribed at 4.5 g per night (2.25 g x 2) for 2 weeks First night after V2: Dose increased to 6 g per night (3 g x 2) for 2 weeks, according to investigator's opinion, tolerance of drug and CGI-S First night after V3: Dose either maintained stable at 6 g or increased to 9 g per night (4.5 g x 2) with dose increments of 1.5 g per night (0.75 g x 2) every week, based on benefit-risk ratio, for 2 weeks.~First night after V4: Dose maintained at 9 g or reduced at 6 g per night according to benefit-risk ratio for 2 weeks. No dose adjustment during the Maintenance period.~First night after V5: Taper period. Dose decrease by 2.25 g x 2 every two days until complete withdrawal"

Xyrem Placebo: sodium citrate solution in equimolar concentration of sodium in the 500 mg/mL Xyrem oral solution, PH adjusted with malic acid