Dosing and uses of Brexpiprazole (Rexulti)
Adult dosage forms and strengths
tablet
- 0.25mg
- 0.5mg
- 1mg
- 2mg
- 3mg
- 4mg
Schizophrenia
Indicated for schizophrenia
Recommended starting dose: 1 mg PO qDay on Days 1 through 4
Recommended target dose: 2-4 mg PO qDay; titrate to 2 mg qDay on Days 5 through 7, and then to 4 mg/day on Day 8 based on the patient’s clinical response and tolerability
Not to exceed 4 mg/day
Periodically reassess to determine the continued need and appropriate dose
Depression
Indicated as adjunctive treatment for major depressive disorder
Recommended starting dose: 0.5 mg or 1 mg PO qDay
Recommended target dose: 2 mg PO qDay; at weekly intervals, titrate to 1 mg/day, and then up to 2 mg/day
Titrate according to clinical response and tolerability
Not to exceed 3 mg/day
Periodically reassess to determine the continued need and appropriate dose
Dosage modifications
Hepatic impairment
- Moderate-to-severe hepatic impairment (Child-Pugh ≥7)
- MDD: Not to exceed 2 mg/day
- Schizophrenia: Not to exceed 3 mg/day
Renal impairment
- Moderate, severe, or ESRD (CrCl <60 mL/min)
- MDD: Not to exceed 2 mg/day
- Schizophrenia: Not to exceed 3 mg/day
CYP2D6 poor metabolizers
- CYP2D6 poor metabolizers: Administer half of the usual brexpiprazole dose
- Known CYP2D6 poor metabolizers taking strong/moderate CYP3A4 inhibitors: Administer a quarter of the usual brexpiprazole dose
CYP2D6 or CYP3A4 inhibitors
- Strong CYP2D6 inhibitors: Administer half of the usual brexpiprazole dose (see note below for MDD)
- Strong CYP3A4 inhibitors: Administer half of the usual brexpiprazole dose
- Strong/moderate CYP2D6 inhibitors plus strong/moderate CYP3A4 inhibitors: Administer a quarter of the usual brexpiprazole dose
- If the coadministered drug is discontinued, adjust the brexpiprazole dosage to its original level
- NOTE: In MDD clinical trials, brexpiprazole dosage was not adjusted for strong CYP2D6 inhibitors (eg, paroxetine, fluoxetine); thus, CYP considerations are already factored into general dosing recommendations and brexpiprazole may be administered without dosage adjustment in patients with MDD
CYP3A4 inducers
- Strong CYP3A4 inducers: Double usual dose over 1 to 2 weeks
- If the coadministered CYP3A4 inducer is discontinued, reduce the brexpiprazole dosage to the original level over 1-2 weeks
Geriatric Dosage & Uses
Antipsychotic drugs increase the risk of death in elderly patients with dementia-related psychosis
Brexpiprazole is not approved for the treatment of patients with dementia-related psychosis (see Black box warnings)
Pediatric dosage forms and strengths
Safety and efficacy not established
Brexpiprazole (Rexulti) adverse (side) effects
>10%
Akathisia (4-14%)
1-10%
Headache (4-9%)
Weight increased (3-8%)
Nasopharyngitis (1-7%)
Extrapyramidal symptoms, excluding akathisia (5-6%)
Somnolence (4-6%)
Dyspepsia (2-6%)
Constipation (1-6%)
Tremor (2-5%)
Fatigue/sedation (2-5%)
Dizziness (1-5%)
Increased CPK blood levels (2-4%)
Decreased cortisol levels (2-4%)
Anxiety (2-4%)
Restlessness (2-4%)
Increased appetite (2-3%)
Diarrhea (1-3%)
Frequency Unknown
Dystonia
Warnings
Black box warnings
Elderly patients with dementia-related psychosis treated with antipsychotic drugs are at increased risk of death; brexpiprazole is not approved for the treatment of patients with dementia-related psychosis
Antidepressants increase the risk of suicidal thoughts and behaviors in patients aged ≤24 yr; monitor for clinical worsening and emergence of suicidal thoughts and behaviors
Safety and effectiveness have not been established in pediatric patients
Contraindications
Hypersensitivity; reactions have included rash, facial swelling, urticaria, and angioedema
Cautions
Increased mortality in elderly patients with dementia-related psychosis (see Black box warnings); in placebo-controlled trials with risperidone, aripiprazole, and olanzapine in elderly patients with dementia, there was a higher incidence of cerebrovascular adverse reactions (cerebrovascular accidents and transient ischemic attacks), including fatalities, compared with placebo
Suicidal thoughts and behaviors reported in children, adolescents, and young adults who are taking antidepressant drugs (see Black box warnings)
Potentially fatal neuroleptic malignant syndrome (NMS) reported in association with administration of antipsychotic drugs
Potentially irreversible, involuntary, dyskinetic movements (ie, tardive dyskinesia) reported with antipsychotic drugs; incidence highest in elderly persons, especially elderly women
Atypical antipsychotic drugs have been associated with metabolic changes that include hyperglycemia/diabetes mellitus (including extreme cases associated with ketoacidosis or hyperosmolar coma or death), dyslipidemia, and body weight gain
May cause leukopenia, neutropenia, and agranulocytosis; monitor and discontinue if severe neutropenia (ANC <1000/mm³)
Orthostatic hypotension or syncope may occur (rare)
Caution with a history of seizures or with conditions/drugs that potentially lower the seizure threshold
Body temperature dysregulation: Disruption of the body’s ability to reduce core body temperature has been attributed to antipsychotic agents
Dysphagia: Esophageal dysmotility and aspiration pneumonia reported
Sedation and hypersomnia reported that may cause impaired judgement, thinking, or motor skills
Pregnancy
Pregnancy
Rexulti pregnancy exposure registry: Monitors pregnancy outcomes in women exposed to brexpiprazole during pregnancy; for more information contact the National Pregnancy Registry for Atypical Antipsychotics at 1-866-961-2388 or visit https://womensmentalhealth.org/clinical-and-research-programs/pregnancy
Adequate and well-controlled studies have not been conducted with brexpiprazole in pregnant women to inform drug-associated risks; however, neonates whose mothers are exposed to antipsychotic drugs, like brexpiprazole, during the third trimester are at risk for extrapyramidal and/or withdrawal symptoms (eg, agitation, hypertonia, hypotonia, tremor, somnolence, respiratory distress, and feeding disorder)
Animal reproduction studies
- No teratogenicity was observed with oral administration of brexpiprazole to pregnant rats and rabbits during organogenesis at doses up to 73 and 146 times, respectively, of maximum recommended human dose (MRHD) of 4 mg/day on a mg/m² basis
- However, when pregnant rats were administered brexpiprazole during the period of organogenesis through lactation, the number of perinatal deaths of pups was increased at 73 times the MRHD
Lactation
Unknown if distributed in human breast milk
Present in rat milk
The development and health benefits of breastfeeding should be considered along with the mother’s clinical need for the drug and any potential adverse effects on the breastfed infant from the drug or from the underlying maternal condition
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Brexpiprazole (Rexulti)
Mechanism of action
Serotonin-dopamine activity modulator (SDAM) that acts as a partial agonist at 5-HT1A and dopamine D2 receptors at similar potency, and an antagonist at 5-HT2A and noradrenaline alpha1B/2C receptors
Absorption
Absolute bioavailability: 95%
Peak plasma time: 4 hr
Steady-state concentration: 1-12 days
Distribution
Protein bound: >99% to serum albumin and alpha-1-acid glycoprotein; its protein binding is not affected by renal or hepatic impairment
Brexpiprazole protein binding is not affected by warfarin, diazepam, or digitoxin
Vd: 1.56 L/kg
Metabolism
Metabolized primarily by CYP2D6 and CYP3A4 isoenzymes
Elimination
Half-life: 91 hr
Clearance: 19.8 mL·hr/kg
Excretion: 25% urine; 46% feces
Administration
Instructions
May take with or without food
