Naltrexone should not be used with pregnant women, individuals with severe liver or kidney damage or with patients who cannot achieve abstain from drugs (Tylenol #3, codeine, Vicodin, Percodan, Darvon, Demerol, Dilaudid, Fentanyl, Methadone, Numorphan, Talwin, morphine, heriod, or opium) for at least 5 days prior to the study and during the study. Also, people who are dependent on opioid drugs, like heroin or morphine must stop their drug use at least 7 days prior to starting naltrexone.

We have screened you for factors such as liver or kidney damage and pregnancy before enrollment in the study.  You will take another pregnancy test right before you take naltrexone again, at the end of the study.