THE EFFECT OF GAMMA-HYDROXYBUTYRIC ACID ON NALOXONE-PRECIPITATED OPIATE WITHDRAWAL

Because gamma-hydroxybutyric acid (GHB), a GABA metabolite, attenuated spontaneous opiate withdrawal in a prior study, we studied GHB effect on naloxone-precipitated opiate withdrawal. Eight opiate-dependent in patients were stabilized on the opioid levorphanol, 18 mg daily. After an initial acclimatization challenge, subjects underwent three double -blind challenges on consecutive days. Pretreatment in a balanced rand omization was with either placebo, GHB, 15 mg/kg, or GHB, 30 mg/kg,fol lowed an hour later by intravenous naloxone, 0.4 mg/70 kg. GHB produce d no significant attenuation of multiple withdrawal measures except fo r hot-cold feelings. GHB pretreatment slightly accelerated respiration prior to naloxone. Differences with prior studies may be due to (1) t iming of GHB administration (giving postwithdrawal in prior studies), (2) direct reversal of GHB's anti-withdrawal effects by naloxone, or ( 3) differences between naloxone-precipitated and spontaneous opiate wi thdrawal.