<prompt> Which of the following statements is FALSE about Naltrexone?Parenterally administeredUsed to prevent relapse of heavy drinkingLong actingCause hepatotoxicity  <response>: Ref: KDT 6e p467 Naltrexone is chemically related to Naloxone and is a pure opioid antagonist. It is more potent than Naloxone. It differs from Naloxone in being orally active and having a long duration of action 1-2 days which is used to prevent relapse of heapy drinking. Side effects are nausea and headache; high doses can cause hepatotoxicity. 