Pharmacology General b6526d00 Naltrexone is: March 2013 A (mu) agonist B 6 (delta) agonist C lc (kappa) antagonist D NOP receptor antagonist High-Yield Explanation Ans. C i.e. lc antagonist Naltrexone is an opioid receptor antagonist used primarily in the management of alcohol dependence and opioid dependence.