Naltrexone is used to maintain abstinence following opioid withdrawal in addicts. It blocks all of the following features of opioid use, except:
Ref: Goodman and Gilman 12th/661 *Naltrexone has no action in the absence of agonists but promptly reverses the opioid effects when administered i.v. *It can reverse all effects of opioid like sedation, analgesia, constipation, respiratory depression and Miosis etc but it do not reduce craving.
Euphoriant effects of opioid
Craving for opioid
Miosis
Respiratory depression
Central Nervous system