Gamma-hydroxybutyric acid as hypnotic. Clinical and pharmacokinetic evaluation of gamma-hydroxybutyric acid as hypnotic in man.

Gamma-Hydroxybutyric acid (GOH) was administered to three groups of four patients in 50, 75 or 100 mg/kg dose respectively, and sleep effects were scored, by sleep observation and questionnaire; GOH plasma levels were determined at 75-100 mg/kg, saliva and urine excretion at 100 mg/kg. Sleep induction was rapid and irresistible, subjects awoke at plasma levels of 90 micrograms/ml; sleep scores were good for 75 mg/kg, excellent for 100 mg/kg, notably on mood. For 75 or 100 mg/kg GOH had virtually disappeared from the blood eight hours after intake; twelve hours after intake no more GOH was detectable in urine; no correlation between plasma- and saliva levels was found. Plasma levels for 100 mg/kg dose were not at an anaesthetic level. So, GOH is a safe and good hypnotic at 75 or 100 mg/kg in clinical use.