Agonist/Antagonist Opioid Analgesics. When a affected person has Formerly been given or is presently undergoing a system of therapy with a pure opioid agonist analgesic like Dilaudid, agonist/antagonist analgesics like pentazocine, nalbuphine, butorphanol, and buprenorphine, must be used with caution.Given The present opioid crisis, a pharmacist'