Human abuse liability assessment of oxycodone combined with ultra-low-dose
naltrexone.
Author(s): Tompkins DA, Lanier RK, Harrison JA, Strain EC, Bigelow GE.
Affiliation(s): Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School
of Medicine, Baltimore, MD, USA. dtompki1@jhmi.edu
Publication date & source: 2010, Psychopharmacology (Berl). , 210(4):471-80
RATIONALE: Prescription opioid abuse has risen dramatically in the United States
as clinicians have increased opioid prescribing for alleviation of both acute and
chronic pain. Opioid analgesics with decreased risk for abuse are needed.
OBJECTIVE: Preclinical and clinical studies have shown that opioids combined with
ultra-low-dose naltrexone (NTX) may have increased analgesic potency and have
suggested reduced abuse or dependence liability. This study addressed whether
addition of ultra-low-dose naltrexone might decrease the abuse liability of
oxycodone (OXY) in humans.
MATERIALS AND METHODS: This double-blind, placebo-controlled study systematically
examined the subjective and physiological effects of combining oral OXY and
ultra-low NTX doses in 14 experienced opioid abusers. Seven acute drug conditions
given at least 5 days apart were compared in a within-subject crossover design:
placebo, OXY 20 mg, OXY 40 mg, plus each of the active OXY doses combined with
0.0001 and 0.001 mg NTX.
RESULTS: The methods were sensitive to detecting opioid effects on abuse
liability indices, with significant differences between all OXY conditions and
placebo as well as between 20 and 40 mg OXY doses on positive subjective ratings
(e.g., "I feel a good drug effect" or "I like the drug"), on observer- and
participant-rated opioid agonist effects, and on a drug-versus-money value
rating. There were no significant differences or evident trends associated with
the addition of either NTX dose on any abuse liability indices.
CONCLUSIONS: The addition of ultra-low-dose NTX to OXY did not decrease abuse
liability of acutely administered OXY in experienced opioid abusers.
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