Brexpiprazole (Rexulti)
Atypical antipsychotic D2/5-HT1A partial agonist and 5-HT2A antagonist; structural relative of aripiprazole with lower intrinsic D2 activity and potentially less akathisia. Approved for schizophrenia, adjunctive treatment of major depressive disorder, and agitation associated with Alzheimer's dementia. 1-4 mg PO once daily (target 2-4 mg schizophrenia, 2 mg adjunctive MDD). Plasma half-life ~91h. Oral bioavailability ~95%. Extensive CYP3A4/2D6 metabolism, reduce dose by 50% in poor CYP2D6 metabolizers or with strong inhibitors. Weight gain and akathisia are leading AEs.
Projected serum levels — 2 mg, once daily
Maintenance schedule: 2 mg once daily (oral).
Loading schedule: 6 mg on day 1, then 2 mg once daily — reaching therapeutic levels sooner.
Modeled steady state after ~10 days: peak ≈ 10.8 mg, trough ≈ 9.2 mg body load. Population-based estimate over 30 days for a 2 mg dose at a 70 kg reference body mass — the interactive app scales curves to your doses, timing, and body mass.
Key facts
- Category
- Antipsychotic
- Route modeled
- Oral
- Model confidence
- inferred
- Half-life
- 3.8 days
- Common dose
- 2 mg
- Suggested maximum
- 4 mg/day
- Reference dose range
- 1–4 mg (single dose)
- Suggested cadence
- once daily
- Validated against
- 4 mg oral — Cmax 0.090 mg/L at 4 h
Documented interactions
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danger
25I-NBOMe + Brexpiprazole (Rexulti)
25I-NBOMe and Brexpiprazole (Rexulti) both have serotonergic activity. Risk of serotonin syndrome (hyperthermia, rigidity, autonomic instability, altered mental status).
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danger
2C-I (2,5-Dimethoxy-4-iodophenethylamine) + Brexpiprazole (Rexulti)
2C-I (2,5-Dimethoxy-4-iodophenethylamine) and Brexpiprazole (Rexulti) both have serotonergic activity. Risk of serotonin syndrome (hyperthermia, rigidity, autonomic instability, altered mental…
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danger
2C-B (4-Bromo-2,5-dimethoxyphenethylamine) + Brexpiprazole (Rexulti)
2C-B (4-Bromo-2,5-dimethoxyphenethylamine) and Brexpiprazole (Rexulti) both have serotonergic activity. Risk of serotonin syndrome (hyperthermia, rigidity, autonomic instability, altered mental…
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danger
3-MeO-PCP (3-Methoxyphencyclidine) + Brexpiprazole (Rexulti)
3-MeO-PCP (3-Methoxyphencyclidine) and Brexpiprazole (Rexulti) both have serotonergic activity. Risk of serotonin syndrome (hyperthermia, rigidity, autonomic instability, altered mental status).
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danger
4-AcO-DMT (Psilacetin) + Brexpiprazole (Rexulti)
4-AcO-DMT (Psilacetin) and Brexpiprazole (Rexulti) both have serotonergic activity. Risk of serotonin syndrome (hyperthermia, rigidity, autonomic instability, altered mental status).
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danger
5-HTP (5-Hydroxytryptophan) + Brexpiprazole (Rexulti)
5-HTP (5-Hydroxytryptophan) and Brexpiprazole (Rexulti) both have serotonergic activity. Risk of serotonin syndrome (hyperthermia, rigidity, autonomic instability, altered mental status).
Serum checks 349 modeled interaction pairings for brexpiprazole (rexulti) across your whole stack — absorption conflicts, enzyme inhibition, and nutrient depletion included.
Research behind this entry
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Brexpiprazole: pharmacokinetics, pharmacodynamics, and drug interactions
Clinical pharmacology review: ~91h half-life, CYP2D6/3A4 metabolism, and dose adjustment guidance with interacting drugs and poor metabolizers.
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Efficacy and safety of adjunctive brexpiprazole 2 mg in major depressive disorder
Pivotal phase 3 trial establishing adjunctive brexpiprazole 2 mg efficacy in antidepressant-inadequate-response MDD.
2 published studies referenced in the app, each with a plain-language summary.