What is the treatment for tremors (shaky hands) caused by Latuda (lurasidone)?

Treatment of Latuda-Induced Tremor with Cogentin

Benztropine (Cogentin) is an appropriate and effective treatment for tremor caused by Latuda (lurasidone), as it directly addresses the extrapyramidal symptoms (EPS) that antipsychotics commonly produce. 1, 2

Understanding Latuda-Related Tremor

Lurasidone is associated with parkinsonism and extrapyramidal symptoms, particularly early in treatment, which manifests as tremor, rigidity, and bradykinesia 1, 2. These side effects occur because lurasidone blocks dopamine D2 receptors in the nigrostriatal pathway, creating a relative dopamine deficiency that produces parkinsonian symptoms 1.

Why Benztropine Works

Benztropine is an anticholinergic medication that restores the balance between dopamine and acetylcholine in the basal ganglia, effectively treating drug-induced parkinsonism and tremor. 3 The mechanism addresses the underlying neurochemical imbalance created by D2 receptor blockade.

Dosing and Administration

• Start with benztropine 0.5-1 mg once or twice daily, with a maximum dose of 6 mg/day divided into 2-3 doses 3
• The medication can be taken orally and typically shows improvement within days to weeks 3
• Dose adjustments should be made gradually based on symptom response and tolerability 3

Alternative Management Strategies

Dose Reduction of Lurasidone

• Consider reducing the lurasidone dose first, as higher doses (above 80 mg/day) are associated with increased rates of somnolence, akathisia, and parkinsonism without additional efficacy benefit 2
• The recommended therapeutic range is 40-80 mg/day, and doses above this may increase EPS without improving outcomes 1, 2

Beta-Blockers

• Propranolol is effective for most types of tremor and can be considered as an alternative or adjunct to benztropine 4
• This option is particularly useful if the tremor has both parkinsonian and action tremor components 4

Important Monitoring and Precautions

Anticholinergic Side Effects

• Monitor for anticholinergic effects including dry mouth, constipation, urinary retention, blurred vision, confusion, and memory impairment 3
• Elderly patients and those with cognitive impairment are at higher risk for anticholinergic toxicity 3
• Constipation can be particularly problematic and may require proactive management with stool softeners 3

Gastroparesis Risk

• Anticholinergics can worsen gastrointestinal motility and should be used cautiously in patients with any history of gastroparesis or severe constipation 3
• Metoclopramide, sometimes used for gastroparesis, can worsen EPS and should be avoided in patients already experiencing drug-induced parkinsonism 3

Cognitive Effects

• Anticholinergics may impair cognition, particularly in vulnerable populations, and this risk must be weighed against the benefit of tremor control 3

When Benztropine May Not Be Sufficient

If tremor persists despite adequate benztropine dosing:

• Re-evaluate whether the tremor is truly parkinsonian or if it represents akathisia, which requires different treatment (beta-blockers or benzodiazepines rather than anticholinergics) 1, 2
• Consider switching to an antipsychotic with lower EPS risk if the tremor significantly impacts quality of life and cannot be adequately managed with adjunctive medications 1
• Lurasidone has a favorable metabolic profile compared to many antipsychotics, so switching should be carefully considered against the benefits of maintaining current therapy 1, 5

Practical Implementation Algorithm

1. Confirm the tremor is parkinsonian (resting tremor, rigidity, bradykinesia) rather than action tremor or akathisia 4, 1
2. Verify lurasidone is being taken with at least 350 calories of food, as improper administration can affect drug levels and side effects 2
3. If lurasidone dose is >80 mg/day, consider dose reduction first before adding benztropine 2
4. If dose is already optimal (40-80 mg/day), initiate benztropine 0.5-1 mg once or twice daily 3
5. Titrate benztropine gradually every 5-7 days based on response, monitoring for anticholinergic side effects 3
6. If tremor persists despite benztropine 4-6 mg/day, consider adding propranolol or re-evaluating the diagnosis 4

Long-Term Considerations

• Anticholinergics should not be used indefinitely without periodic reassessment, as EPS may diminish over time with continued antipsychotic use 3
• Attempt to taper benztropine after 3-6 months of stable symptoms to determine if it remains necessary 3
• Close monitoring during benztropine taper is essential, as abrupt discontinuation can cause rebound worsening of EPS 3