Treatment of Brexpiprazole-Induced Akathisia in Bipolar Disorder
For akathisia caused by Rexulti (brexpiprazole) 2 mg, first reduce the dose to 1 mg or discontinue the medication entirely, and simultaneously initiate propranolol 10-30 mg two to three times daily as first-line pharmacologic treatment. 1
Immediate Management Strategy
First-Line Approach: Dose Reduction or Discontinuation
- Lower the brexpiprazole dose from 2 mg to 1 mg daily, as dose reduction is the most direct intervention for antipsychotic-induced akathisia 1, 2
- If akathisia is severe or intolerable, discontinue brexpiprazole entirely and consider switching to an alternative antipsychotic with lower akathisia risk 3, 4
- Akathisia with brexpiprazole can occur even at low introductory doses and may resolve completely upon discontinuation 5
Concurrent Pharmacologic Treatment
- Initiate propranolol (or another lipophilic beta-blocker) at 10 mg two to three times daily, titrating up to 30 mg three times daily as needed 2, 6
- Beta-blockers represent the most consistently effective treatment for acute akathisia based on available evidence 6
- The American Psychiatric Association specifically recommends beta-adrenergic blocking agents as one of the primary options for antipsychotic-induced akathisia 1
Second-Line Options if Beta-Blockers Fail
Benzodiazepines
- Add a benzodiazepine (such as lorazepam 0.5-2 mg twice daily) if propranolol is insufficient, particularly if subjective distress persists 1, 6
- Benzodiazepines are explicitly recommended by APA guidelines as an alternative treatment option for akathisia 1
- However, exercise caution in bipolar disorder as benzodiazepines may cause disinhibition, though this concern is primarily documented in younger children 7
Alternative Agents
- If both beta-blockers and benzodiazepines fail, consider amantadine (100-300 mg daily) or clonidine 6
- Emerging evidence suggests mirtazapine may be useful for acute akathisia, though data are limited 8
Switching Antipsychotic Strategy
Lower Akathisia Risk Alternatives
- Switch to quetiapine or olanzapine, which have substantially lower akathisia rates compared to brexpiprazole 3, 4, 2
- Quetiapine causes minimal akathisia (6 ms mean QT prolongation) compared to other antipsychotics 4
- Olanzapine has one of the lowest akathisia profiles (2 ms mean QT prolongation) among atypical antipsychotics 4
Considerations for Bipolar Disorder with Paranoia
- Both quetiapine and olanzapine are FDA-approved for acute mania in adults 7
- Olanzapine is also approved for maintenance therapy in bipolar disorder 7
- The patient's concurrent lithium therapy (only 1 week duration) should be continued as lithium is the only FDA-approved agent for bipolar disorder in youth aged 12+ and has disease-modifying properties 7, 9
Critical Clinical Pitfalls
Avoid Anticholinergic Agents
- Do not use anticholinergic medications (such as benztropine or trihexyphenidyl) for akathisia, as they are not consistently helpful and may worsen cognitive function 3, 1
- Anticholinergics are specifically recommended only for acute dystonia and parkinsonism, not akathisia 1
Monitor for Misdiagnosis
- Akathisia is frequently misinterpreted as psychotic agitation, anxiety, or worsening of the underlying psychiatric condition 3, 4
- This misdiagnosis commonly leads to inappropriate dose increases rather than reduction, worsening the problem 3
- Akathisia is a major cause of medication noncompliance and can significantly impact quality of life 3
Timing Considerations
- Akathisia typically occurs within the first few days of antipsychotic therapy or after dose increases 4
- The patient has been on lithium for only 1 week, making brexpiprazole the more likely culprit, though lithium can contribute to tremor (distinct from akathisia) 7
Brexpiprazole-Specific Context
Akathisia Incidence with Brexpiprazole
- Akathisia was the only adverse event with ≥5% incidence in brexpiprazole trials that exceeded placebo rates 10, 11, 12
- Despite being a partial dopamine agonist designed to have lower akathisia rates than aripiprazole, brexpiprazole still causes significant akathisia in clinical practice 11, 12, 5
- Rates appear lower than aripiprazole but higher than quetiapine or olanzapine 11
Failed Bipolar Mania Trials
- Two phase 3 trials of brexpiprazole for acute bipolar mania failed to show statistical superiority over placebo 10
- Akathisia was noted as a significant adverse effect in these trials 10
- This suggests limited evidence for brexpiprazole's efficacy in bipolar disorder specifically, supporting consideration of alternative agents 10