Abuse Liability of Suboxone Versus Subutex
Condition: Opioid-related Disorders
MeSH terms: Opioid-Related Disorders
Study type: Interventional
Phase: Phase 3

Summary: 
      The study is designed to compare the abuse liabilities of intravenous buprenorphine and
      buprenorphine/naloxone in individuals who are physically dependent on sublingual
      buprenorphine. We hypothesize that the abuse liability of buprenorphine/naloxone is lower
      than that of buprenorphine alone.
    

Detailed description: 
      Drug dependence is a major international public health problem of which opioid dependence,
      notably involving heroin, is a major component. Opioid dependence affects an estimated 13
      million injection drug users (IDUs) worldwide. The high health service costs for the
      treatment of diseases related to non-medical drug use and the high cost to society of
      drug-related behavior have prompted researchers to seek new medications and treatment
      strategies for opioid dependence. Buprenorphine, a mu-opiate receptor partial agonist and
      kappa-opiate receptor antagonist, is one such new medication that has had a significant role
      in expanding access to effective opioid dependence treatment. It is available as Subutex
      (buprenorphine alone) or Suboxone (a combination of buprenorphine and naloxone). Although it
      is commonly believed that the abuse potential of buprenorphine is low, numerous countries
      have reported illicit diversion of buprenorphine and a growing population of buprenorphine
      abusers. Theoretically, Suboxone would have lower abuse potential. When used sublingually, as
      prescribed, the amount of naloxone absorbed is negligible. However, if a patient crushes the
      tablet and attempts to inject or sniff the medication, the naloxone will become effective as
      an opioid antagonist and may precipitate withdrawal signs and symptoms in individuals
      dependent on full opioid agonists and/or attenuate the euphoric effects of the buprenorphine
      that is also contained in the medication. To date, few laboratory studies have evaluated the
      abuse liability of buprenorphine in humans using a drug self-administration protocol. We are
      proposing to evaluate the abuse potential of intravenous (IV) buprenorphine compared to IV
      buprenorphine/naloxone in buprenorphine-maintained injection drug users (IDUs), incorporating
      self-administration procedures with other measures of opioid effects. The proposed study will
      investigate the conditions that affect the self-administration of IV buprenorphine by
      buprenorphine abusers. The primary aim of the study is to compare the reinforcing effects of
      IV buprenorphine and IV buprenorphine/naloxone in IDUs maintained on different doses of
      sublingual buprenorphine (2, 8, and 24 mg/day). Secondary aims of the study are to compare
      the subjective, performance and physiological effects of IV buprenorphine and IV
      buprenorphine/naloxone. IV-administered placebo (saline), naloxone alone, and heroin alone
      will be tested as neutral, negative, and positive control conditions, respectively.
      Participants (N=12 completers) will reside on an inpatient unit (the General Clinical
      Research Unit, GCRU) during a 7 to 8-week study. This research will provide useful
      information for clinicians treating opioid dependent individuals with buprenorphine, and
      importantly, will provide information about the abuse potential and effects of buprenorphine
      on multiple measures of human functioning.
    

Intervention name(s): Heroin; Naloxone; Low Bup Dose; High Bup Dose; Low Bup/Nal Dose; High Bup/Nal Dose; Placebo (PCB)
Intervention type(s): Drug; Drug; Drug; Drug; Drug; Drug; Drug
Intervention description(s): Heroin (25 mg); .4 mg; 4 and 8 mg; 8mg and 16 mg; Buprenorphine/Naloxone 4/1 mg, 8/2 mg; Buprenorphine/Naloxone 8/2 mg, 16/4 mg; Placebo control administration
Other intervention name(s): Diacetylmorphine; Naloxone Hydrochloride (HCl); Subutex; Subutex; Suboxone; Suboxone; 0 mg
Intervention MeSH terms: Buprenorphine, Naloxone Drug Combination; Buprenorphine; Heroin; Naloxone
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Basic Science