Naltrexone is an FDA-approved drug that helps people beat addiction by blocking the effects of opioids and alcohol. Yet it’s not as widely known, or used, as the synthetic opioid medication methadone. St. Louis journalist Ben Westhoff’s new documentary “Antagonist” explores why. Westhoff and Assisted Recovery Centers of America President Percy Menzies join us to discuss why naltrexone is so effective at treating opioid and alcohol misuse and how the drug got sidelined by big money interests.