None listed
Conditions
Brief summary
We propose to examine the effects of regular Naltrexone dosing as an off-label treatment for problem gamblers. We plan to examine the neural activation when we present gambling stimuli, are asked to make self-controlled or impulsive hypothetical choices and when subjects have to inhibit a learned response. Participants will be tested pre and post treatment and correlate these responses with the urge to gamble and self-reported gambling behaviour. By examining these relationships, specifically the change in neurological functioning, we hope to find the neural correlates to measures of problem gambling. Investigating these issues will assist in the analysis of a putative common neurological basis between gambling and alcoholism and hopefully advance both treatments
Interventions
Regular Naltrexone dosing. Initially, participants will be given seven 25mg oral Naltrexone (ReVia; Bristol-Myers Squib) half tablets at intake (to be taken one a day for seven days). The full dosing regimen will begin if no toxicity issues are observed during the previous week and consists of 7 50mg tablets (one per day for seven days). If gambling urges continue dosages can be stepped up in weekly increments to 21 oral 50mg tablets per week (maximum of three 50mg tablets per day). Therefore, d
Regular Naltrexone dosing. Initially, participants will be given seven 25mg oral Naltrexone (ReVia; Bristol-Myers Squib) half tablets at intake (to be taken one a day for seven days). The full dosing regimen will begin if no toxicity issues are observed during the previous week and consists of 7 50mg tablets (one per day for seven days). If gambling urges continue dosages can be stepped up in weekly increments to 21 oral 50mg tablets per week (maximum of three 50mg tablets per day). Therefore, daily dosages can range between 25mg to 150mg. The treatment duration is 8-12 weeks depending on efficacy of medication (12 weeks of treatment is scheduled but can be reduced to 8 if significant improvements have been observed).
Sponsors
Problem Gambling Research and Treatment Centre, University of Melbourne
Study design
Allocation
Non-randomised trial
Intervention model
Single group
Primary purpose
Treatment
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
18 Years to 70 Years
Healthy volunteers
Yes
Inclusion criteria
18-70 years of age. Provide written consent. Evidence of Problem Gambling (PGSI). Seeking treatment for problem gambling. Primarily Electronic Gaming Machine (EGM) gamblers. English speaking.
Exclusion criteria
Evidence of a current significant medical illness, psychiatric or neurological disorder (except for medically unmanaged anxiety, mood, and antisocial personality disorders) as indicated by responses to the MINI or semi-structured life histories questionnaire (e.g. medical, psychiatric, and drug histories). Positive urine specimen to drugs of abuse. History of a traumatic brain injury or loss of consciousness (10 minutes or more). History of evidence of claustrophobia Failure to follow laboratory or study procedures. Left handed. Any condition or circumstance that prohibit imaging sessions such as metal implants. Contraindications to clinical doses of Naltrexone (e.g. currently using opioid analgesics, are opioid dependent, have acute hepatitis, hypersensitivity to Naltrexone, liver/kidney hypertoxicty, or hepatotoxicity). History or evidence of allergic reactions to Naltrexone administration (i.e., rash, itching/swelling, severe dizziness, trouble breathing)/ Concurrent use of additional alcohol dependence medication e.g. disulfiram. Evidence of current illicit opioid use Use of medications containing opioids/opiates Uncorrected visual impairment Evidence of brain abnormalities from structural scans Evidence of heart, liver or kidney failure. We will test for liver function in two ways. First, creatinine levels will be assessed to measure general liver function, where levels outside the normal range (Males: 0.6 – 1.2 mg/dl, Females: 0.5 – 1.1 mg/dl) will exclude participation. Second, we will test for aminotransferase liver enzymes in the blood, specifically; aspirate aminotransferase (AST) and alanine aminotransferase (ALT) in a selective blood metabolic panel. Scores outside the normal range for AST (Males: 15 – 40 U/L, Females: 13 – 35 U/L) or ALT (Males; 10 – 40, Females: 7 – 35) will exclude participation. The definition of heart failure we will use is the inability of the heart to supply sufficient blood flow to meet the needs of the body (Medterms.com, 2011), as evidenced in a clinical interview and physical examination by our physicians.
Outcome results
None listed