Naltrexone may cause severe withdrawal symptoms in patients with opioids in their
system during the period of detoxification. That is why it is very important for such
patients to maintain abstinence during 7 to 10 days before treatment is started. But
these symptoms are actually opioid withdrawal symptoms, not Naltrexone's. As for
Naltrexone itself, it does not cause physical dependence or produce negative
reactions when discontinued. In case with alcohol, it does not even produce any
unpleasant feelings when the patient relapses to drinking again, it just reduces the
craving for alcohol.
