Buprenorphine partial agonist at which opioid receptor?

Ans. is 'a' i.e., Mu o Buprenorphine is partial agonist on mu receptor and antagonist at Kappa receptor.Nature of interaction of opioid ligands with the three major types of opioid receptors, along with equivalent analgesic dosesLigandm (mu)k (kappa)d (delta)Analgesic dose (mg)1. MorphineAgo. (St)Ago. (W)Ago. (W)102. NalorphineAnta. (St)Ago. (M)--3. PentazocineP. Ago., Anta. (W)Ago. ( M)-30-604. ButorphanolP. Ago. (W)Ago. (St)-1-35. BuprenorphineP. Ago.Anta. (M)-0-3-046. NaloxoneAnta. (St)Anta. (M)Anta. (W)-7. NaltrexoneAnta. (St)Anta. (M)Anta. (W)_8. Met/Leu enkephalinAgo. (M)-Ago. (St)_9. (3-EndorphinAgo. (St)-Ago. (St)_10. Dynorphin A, BAgo. (W)Ago. (St)Ago. (W)-