Naltrexone is an opioid antagonist,which binds competitively at the opioid
receptors and blocks the effects of exogenous opioids, Naltrexone has been
used to facilitate,withdrawal (in using rapid and ultra rapid withdrawal te
chniques). The research on the efficacy of rapid and ultra-rapid withdrawal
to date is extremely limited. The predominant use of naltrexone is as a po
st-withdrawal relapse prevention intervention. Research has revealed that n
altrexone's acceptability is generally poor, mainly appealing to those high
ly motivated towards achieving and maintaining abstinence. In spite of poor
acceptibility; naltrexone-treated participants often produce lower levels
of craving for opiates, significantly higher rates and longer periods of ab
stinence and significantly greater improvement in psychosocial functioning
than those treated with placebos and standard treatment programmes. The stu
dies of highly motivated participants demonstrated the highest retention an
d completion races, Being employed and having good social support have been
identified as being associated with successful outcome. There also appears
to be a trend towards greater success being associated with older particip
ants, and those with a greater number of previous treatment attempts. The c
ombined use of naltrexone and psychosocial therapy has proved to be more ef
fective than psychosocial therapy alone, and more effective than naltrexone
treatment alone, in improving post treatment outcome. Future research dire
ctions are summarized.