Which enzyme is responsible for metabolizing buprenorphine to norbuprenorphine?

Buprenorphine, a partial agonist at the mu-opioid receptor and antagonist at the kappa-opioid receptor, undergoes metabolic transformation primarily through enzyme systems in the liver. The correct enzyme responsible for metabolizing buprenorphine to its active metabolite, norbuprenorphine, is P450 3A4.

P450 3A4 is one of the most abundant cytochrome P450 enzymes in the liver and is involved in the metabolism of a wide variety of drugs. When buprenorphine is administered, it is processed by this enzyme to create norbuprenorphine, which can then exert its pharmacological effects and undergo further metabolism.

Considering the other options, while P450 1A2, P450 2D6, and P450 2C19 are important for metabolizing other substances, they do not play a significant role in the metabolism of buprenorphine to norbuprenorphine. The specificity of P450 3A4 for buprenorphine highlights its essential function in the pharmacokinetics of this medication, emphasizing the importance of understanding drug interactions and metabolite formation in clinical practice.