The goal of the proposed study is to build knowledge about the effect of Naltrexone in a regular sample of cannabis addicts in a mid-size town. To accomplish this, we propose to: a) do a double blind randomized controlled trial with Naltrexone in…
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Health condition
verslaving aan cannabis
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Intervention
No registrations found.
Outcome measures
Primary outcome
RESEARCH QUESTIONS AND HYPOTHESES
a) In patients with predominantly cannabis addiction, does Naltrexone
significantly reduce craving for cannabis, significantly reduce use of
cannabis, significantly increase general well-being on the MATE-scale, and have
a sginificant effect on the use of other addictive substances?
b) Which are the side effects?
c) Do the side effects cause people to stop taking the medication (Naltrexone
or placebo)?
4.6 Baseline and Outcome Measures
The initial assessment will entail the MATE-scale to establish the
social and general functioning, a short depression questionnaire to rule out a
depressive disorder, a thorough assessment of current cannabis use and the use
of other addictive substances, validated questionnaires for subjective craving
for cannabis (e.g. Desires for Drug Questionnaire, Obsessive Compulsive Drug
Use Scale; Franken et al., 2002), a visual analogue scale for craving for
cannabis (VAS; Franken and Muris, 2005), a VAS for craving for other addictive
substances, blood pressure and pulse, basic blood lab of liver function and
extra blood will be frozen for possible later research on genetic markers.
At two, four, six and eight weeks the assessment will ential an
assessment of the use of the medication, of cannabis use, of the use of other
addictive substances, of side effects, a VAS of craving for cannabis and a VAS
of craving for other addictive substances.
At eight weeks the MATE-scale, blood pressure and pulse, and basic
blood lab of liver function will also be measured.
If at the conclusion of the study there are clear distinct outcomes, we might
use the extra blood for research on genetic markers.
Secondary outcome
d) Are there genetic markers which can predict which patients are more likely
to respond well to Naltrexone?
Background summary
Naltrexone has been widely studied as an anti-craving medication in
alcoholism since 1992. It works by blocking the opiate-receptors in the reward
system. Over the years since its introduction Naltrexone has also been tried
with other addictions. Its use in opiate addiction has been established. There
have also been reports of its use in cocaine addiction and gambling addiction.
The few studies in which Naltrexone has been studied in cannabis addiction have
shown little, or no, favorable outcome.
The principal investigator in this study, Eugène Schouten, is
psychiatrist in the addiction treatment facility (Centrum Maliebaan) in
Amersfoort, The Netherlands. Since 2006 at this facility Naltrexone has been
prescribed on an off-label basis for a variety of addictions. Its use in
alcoholism and cocaine addiction is often, not always, confirmed by the patient
and staff. Also many, not all, patients with cannabis addiction report a
beneficial effect on craving and the abuse of cannabis. The wish to
scientifically investigate the effect of Naltrexone in patients with cannabis
addiction has led to this study.
Study objective
The goal of the proposed study is to build knowledge about the effect of
Naltrexone in a regular sample of cannabis addicts in a mid-size town. To
accomplish this, we propose to: a) do a double blind randomized controlled
trial with Naltrexone in patients with cannabis addiction, who besides
Naltrexone will receive the cognitive-behavioral treatment as ususal
(Leeftstijltraining). Outcome measures will be the effect on cannabis craving,
on cannabis use, on general well-being (MATE-scale) and on the use of other
addictive substances.
b) save extra blood from each participant, so, if in our study there are clear
effects, we can later also investigate genetic aspects of the response to
Naltrexone (for instance regarding the receptors for opiates in the nucleus
accumbens).
c) when in the course of the study there is a clear trend towards a beneficial
effect of Naltrexone over placebo, the patients who will enroll later will be
asked to also participate in an additonal brain-MRI study in which we plan to
investigate the effects of Naltrexone in the reward system of the brain of
patients with cannabis addiction. A separate study protocol will be written for
that study.
Study design
4.5 Study Medication
Naltrexone 50 mg/day or placebo will be administered for eight weeks.
Naltrexone and the placebo are provided by TioFarma BV, Oud-Beijerland.
Patients will be seen by the regular doctors in the outpatient clinic
to monitor their medication, including initial blood pressure measuring and
standard blood lab of liver function. The research assistent will (also
blinded) hand out the medication to the patients and will do most of the
initial and following assessments.
After eight weeks the study will be opened and Naltrexone will be made
available to those patients who have received placebo. After the eight weeks
medication will be given through regular prescriptions and regular pharmacies.
4.6 Baseline and Outcome Measures
The initial assessment will entail the MATE-scale to establish the
social and general functioning, a short depression questionnaire to rule out a
depressive disorder, a thorough assessment of current cannabis use and the use
of other addictive substances, validated questionnaires for subjective craving
for cannabis (e.g. Desires for Drug Questionnaire, Obsessive Compulsive Drug
Use Scale; Franken et al., 2002), a visual analogue scale for craving for
cannabis (VAS; Franken and Muris, 2005), a VAS for craving for other addictive
substances, blood pressure and pulse, basic blood lab of liver function and
extra blood will be frozen for possible later research on genetic markers.
At two, four, six and eight weeks the assessment will ential an
assessment of the use of the medication, of cannabis use, of the use of other
addictive substances, of side effects, a VAS of craving for cannabis and a VAS
of craving for other addictive substances.
At eight weeks the MATE-scale, blood pressure and pulse, and basic
blood lab of liver function will also be measured.
If at the conclusion of the study there are clear distinct outcomes, we might
use the extra blood for research on genetic markers.
4.7 Statistical Power
In order to calculate the sample size of the first study on the effectiveness
of Naltrexone in the treatment of cannabis dependence we will use an alpha of
0.10 and a beta of 0.20 with expectation of serious reductions in craving
(d=0.70) and a substantial difference of 25% in continuous cannabis abstinent
patients at 8 weeks. In this circumstance, about 30 patients per group are
needed.
Intervention
Either Naltrexone 50 mg once daily for eight weeks. Or placebo once daily for
eight weeks.
Study burden and risks
RISKS
The use of Naltrexone can cause various side-effects, although they don*t
develop in all users. Often occurring side-effects include nausea and
nightmares. Rarely occuring side effects include stomach complaints, vomiting,
insomnia, nervousness, irritability, dizziness, diarrhea, anxiety. Since
Naltrexone blocks opiates, participant will be warned that opiates will
probably we less effective when administered to them, for instance in case of a
surgical operation.
Nederland
Nederland
Listed location countries
Age
Inclusion criteria
male or female
between 18 - 60 years old
current primary diagnosis of cannabis abuse or dependence
able to provide written informed consent and to comply with all study procedures
Exclusion criteria
currently dependent on opiates
currently majorly dependant on another substance other than cannabis or nicotine
severe medical illness
known allergy to Naltrexone
Design
Recruitment
Medical products/devices used
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Other (possibly less up-to-date) registrations in this register
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In other registers
Register | ID |
---|---|
EudraCT | EUCTR2010-020779-21-NL |
CCMO | NL25001.097.10 |