This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Opioids and Alcohols, Subject name: Pharmacology
[{'content': 'Buprenorphine is classified as:- \nSelect and explain. \nA. Agonist and antagonist at mu receptors, B. Antagonist at mu receptors, C. Full agonist at mu receptors, D. Paial agonist at mu receptors', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Buprenorphine is paial agonist at mu receptor with kappa and delta antagonistic propey. It is useful as an analgesic and as an alternative to methadone for the management of opioid withdrawal. Nalbuphine, pentazocine and dezocine are k agonists and m receptor antagonists. These drugs can produce psychomimetic effects with hallucinations, nightmares and anxiety. Butorphanol is a predominant k agonist that produces equivalent analgesia but more sedation than morphine.', 'role': 'assistant'}]