Which of the following is used to maintain abstinence in alcohol dependence? REPEAT

Essentials of medical pharmacology; k.d tripathi ;7th edition; pg.no. 393; Naltrexone ,the studies have demonstrated involvement of opioid system in pleasurable reinforcing effect of alcohol through dopamine mediated reward function .The post addict treated with the long acting opioid antagonist does not experience the same pleasurable effect on taking alcohol ;reinforcement is weakened.