Recommended Dosage of Rexulti (Brexpiprazole)
For the treatment of schizophrenia in adults, the recommended starting dose of Rexulti is 1 mg once daily for days 1-4, then 2 mg once daily for days 5-7, with a target dose range of 2-4 mg once daily. 1
Dosage Guidelines for Different Indications
Schizophrenia
- Start with 1 mg once daily for days 1-4 1
- Increase to 2 mg once daily on days 5-7 1
- May increase to maximum recommended dose of 4 mg once daily on day 8 based on clinical response and tolerability 1
- The recommended target dosage is 2-4 mg once daily 1
Major Depressive Disorder (Adjunctive Treatment)
- Start with 0.5 mg or 1 mg once daily 1
- Titrate to 1 mg once daily, then to target dose of 2 mg once daily based on clinical response and tolerability (increase at weekly intervals) 1
- Maximum recommended daily dosage is 3 mg 1
Dosage Adjustments for Special Populations
Hepatic Impairment
- For moderate to severe hepatic impairment (Child-Pugh score ≥7): 1
- Maximum 2 mg once daily for MDD
- Maximum 3 mg once daily for schizophrenia
Renal Impairment
- For patients with creatinine clearance <60 mL/minute: 1
- Maximum 2 mg once daily for MDD
- Maximum 3 mg once daily for schizophrenia
CYP2D6 Poor Metabolizers
- Administer half of the recommended dosage 1
- For known CYP2D6 poor metabolizers taking strong/moderate CYP3A4 inhibitors, administer a quarter of the recommended dosage 1
Drug Interactions and Dosage Modifications
Patients Taking CYP Inhibitors
- Strong CYP2D6 inhibitors: Administer half of the recommended dosage 1
- Strong CYP3A4 inhibitors: Administer half of the recommended dosage 1
- Strong/moderate CYP2D6 inhibitors with strong/moderate CYP3A4 inhibitors: Administer a quarter of the recommended dosage 1
Patients Taking CYP3A4 Inducers
- Double the recommended dosage over 1-2 weeks 1
- If the CYP3A4 inducer is discontinued, reduce the brexpiprazole dosage to the original level over 1-2 weeks 1
Administration
- Brexpiprazole can be taken once daily with or without food 1
- Periodic reassessment is recommended to determine continued need and appropriate dosage for treatment 1
Clinical Considerations
Efficacy
- In clinical trials for schizophrenia, the response rate was 45.5% vs. 31.0% for placebo, with a Number Needed to Treat (NNT) of 7 2
- For maintenance treatment, brexpiprazole significantly delayed time to relapse compared with placebo 3
- For adjunctive treatment of MDD, the response rate was 23.2% vs. 14.5% for placebo, with an NNT of 12 2
Safety and Tolerability
- Generally well tolerated with relatively low incidence of activating and sedating adverse effects 3
- Most common adverse effects include akathisia (5.5% in schizophrenia trials, 8.6% in MDD trials), headache, and gastrointestinal effects 2
- Moderate weight gain may occur, with more significant weight gain (≥7% of body weight) observed in longer-term studies 2
- Effects on glucose, lipids, and prolactin are generally small 2
Important Warnings
- Black box warning for increased mortality in elderly patients with dementia-related psychosis 1
- Black box warning for increased risk of suicidal thoughts and behaviors in pediatric patients and young adults 1
- Monitor patients closely for clinical worsening and emergence of suicidal thoughts and behaviors 1