Naltrexone is used in opioid dependence to -: (A) Prevent respiratory depression, (B) Treat withdrawal symptoms, (C) Prevent relapse, (D) Treatment of opioid overdose
Answer is C. Naltrexone is a pure opioid antagonist. It is competitive antagonist at all opioid receptors. It can be used orally, to assist in the rehabilitation of ex-opioid abusers who are fully withdrawn (otherwise it will induce an acute withdrawal syndrome). A patient who then takes an opioid, fails to experience the kick or euphoria because of the opioid antagonistic actions of the Naltrexone.