Which transporter is listed among the metabolizing enzymes/transporters for brexpiprazole?

• A. P-gp
• B. MRP2
• C. OATP
• D. OCT1

Answer: (A)

Brexpiprazole is affected by efflux transporters that push it out of cells, which helps explain why P-glycoprotein shows up as the listed transporter. P-glycoprotein, abundant in the intestinal lining and at the blood–brain barrier, limits oral absorption and CNS penetration by actively transporting substrates like brexpiprazole back into the gut lumen or out of the brain. Because brexpiprazole is a P-gp substrate, its exposure can be altered by other drugs that inhibit or induce P-gp, making this transporter a key factor in its pharmacokinetics. The other transporters listed (MRP2, OATP, OCT1) are not the ones typically described for brexpiprazole in this context, so they don’t fit as the transporter associated with brexpiprazole in the same way.