What is the daily dose during days 1-4 in the brexpiprazole 5-HT2A occupancy titration schedule?

• A. 4 mg
• B. 2 mg
• C. 1 mg
• D. 0.5 mg

Answer: (C)

The main concept here is how brexpiprazole is titrated to achieve 5-HT2A receptor occupancy while keeping tolerability in mind. To begin engaging the target receptor without rushing into higher exposure, the initial days use a modest daily dose. Specifically, the dose given during days 1 through 4 is 1 mg each day. This sets up a gradual increase in receptor occupancy, allowing the patient to acclimate and allowing clinicians to monitor tolerability before stepping up the dose. After this early phase, the regimen typically moves to higher daily doses if needed to reach the desired therapeutic effect, but that initial four-day period is anchored at 1 mg.