I recently started or increased Abilify (aripiprazole) and now have hand tremor; what should I do?

Hand Tremor After Starting or Increasing Abilify (Aripiprazole)

Reduce your Abilify dose immediately, as tremor is a dose-dependent extrapyramidal side effect that typically resolves with dose reduction or discontinuation. 1, 2

Understanding Aripiprazole-Induced Tremor

Tremor is a recognized extrapyramidal symptom (EPS) associated with aripiprazole, despite its classification as an "atypical" antipsychotic. The FDA drug label explicitly lists tremor as a common side effect, along with other movement disorders including akathisia (restlessness), parkinsonism, and uncontrolled movements. 1

Aripiprazole causes EPS more frequently than initially believed, with clinical studies demonstrating that movement disorders—including tremor, parkinsonism, and akathisia—occur in a substantial proportion of patients. 2, 3 In pediatric populations, the incidence of acute EPS reaches 17.1% (95% CI 12.8-22.3%), significantly higher than placebo. 4

Immediate Management Algorithm

Step 1: Dose Reduction (First-Line Approach)

Reduce your aripiprazole dose by 50% immediately (e.g., from 10 mg to 5 mg, or from 15 mg to 7.5 mg). 2, 5 Case reports demonstrate that parkinsonian symptoms, including tremor, typically resolve within 5 days of dose reduction without requiring additional medication. 5

• Monitor for tremor improvement over the next 5-7 days at the reduced dose. 5
• If tremor persists at the lower dose after one week, proceed to Step 2. 2

Step 2: Medication Discontinuation (If Dose Reduction Fails)

Discontinue aripiprazole entirely if tremor does not improve with dose reduction. 2, 6 Most parkinsonian symptoms, including tremor, abate spontaneously following drug discontinuation, though this may take several weeks. 2

• Tremor related to parkinsonism typically resolves after discontinuation, while tardive phenomena may persist and require treatment. 2
• Do not add anticholinergic medications (such as benztropine) as first-line treatment—dose reduction or discontinuation is more effective and avoids additional medication burden. 7

Step 3: Alternative Antipsychotic Selection (If Continued Treatment Needed)

Switch to quetiapine or olanzapine if you require ongoing antipsychotic treatment, as these agents have lower EPS risk than aripiprazole. 7 However, be aware that these alternatives carry higher metabolic risks (weight gain, diabetes). 7, 8

• Alternatively, consider adjunctive propranolol (10 mg up to 30 mg, two to three times daily) if you must continue aripiprazole at a therapeutic dose. 7

Risk Factors and Clinical Context

Aripiprazole's partial D2 agonist activity does not protect against EPS as initially assumed. 2, 3 The drug can cause:

• Parkinsonism (tremor, rigidity, bradykinesia, shuffling gait) 2, 5, 6
• Akathisia (inner restlessness, need to move) 1, 3, 4
• Acute dystonia (muscle spasms) 4
• Tardive dyskinesia (persistent involuntary movements) 1, 2

The risk of EPS increases at higher doses, making dose reduction the most rational first intervention. 8, 2 Elderly patients, those with hepatic impairment, or poor metabolizers of cytochrome P450 2D6 require lower doses due to increased susceptibility to side effects. 8

Critical Monitoring and Follow-Up

• Assess tremor severity weekly during dose adjustment to determine if further reduction or discontinuation is needed. 2
• Distinguish tremor type: Fine tremor suggests early toxicity, while coarse tremor with confusion or ataxia indicates serious toxicity requiring immediate medical attention. 1
• Monitor for tardive dyskinesia: If involuntary movements persist beyond 2-4 weeks after aripiprazole discontinuation, these may represent tardive phenomena requiring specialized treatment. 2

Common Pitfalls to Avoid

Do not continue aripiprazole at the same dose hoping tremor will resolve spontaneously—EPS typically persists or worsens without dose adjustment. 2, 5

Do not add anticholinergic agents (benztropine, trihexyphenidyl) as first-line treatment for aripiprazole-induced tremor, as dose reduction is more effective and avoids polypharmacy. 7

Do not assume "atypical" means EPS-free—aripiprazole causes movement disorders in a clinically significant proportion of patients, particularly at doses above 10 mg daily. 2, 3, 4

Avoid abrupt discontinuation if you are taking aripiprazole for bipolar disorder or schizophrenia—coordinate with your prescriber to ensure mood stability or psychotic symptom control during any medication changes. 9