Combined Agonist/Antagonist and Partial Agonist Opioid Analgesics The concomitant usage of opioids with other opioid analgesics, like butorphanol, nalbuphine, pentazocine, may well reduce the analgesic effect of oxycodone and acetaminophen tablets and/or precipitate withdrawal symptoms. Recommend patient to prevent concomitant use of such drugs.Rig