From the Guidelines
Avoid using typical antipsychotics like haloperidol, chlorpromazine, and fluphenazine, as well as certain atypical antipsychotics such as risperidone and olanzapine in patients with Lewy body dementia or Parkinson's disease. These medications block dopamine receptors strongly and can significantly worsen motor symptoms, cause severe rigidity, and potentially lead to neuroleptic malignant syndrome, which can be life-threatening 1. Patients with Lewy body dementia are particularly sensitive to these medications and may experience severe adverse reactions even at low doses.
Key Considerations
- The American Psychiatric Association practice guideline on the use of antipsychotics to treat agitation or psychosis in patients with dementia suggests that antipsychotic medications can be appropriate in individuals with dangerous agitation or psychosis, but the benefits are at best small and there is consistent evidence of clinically significant adverse effects, including mortality 1.
- If an antipsychotic is absolutely necessary, quetiapine and clozapine are generally considered safer options due to their lower affinity for dopamine receptors.
- Pimavanserin, which targets serotonin rather than dopamine, is specifically approved for Parkinson's disease psychosis.
- Always start with the lowest possible dose and monitor closely for worsening of motor symptoms or confusion.
- Non-pharmacological approaches should be tried first whenever possible to manage behavioral symptoms in these patients.
Medication Options
- Quetiapine: 25 mg (immediate release) p.o. stat, reduce dose in older patients and patients with hepatic impairment 1.
- Clozapine: generally considered safer due to its lower affinity for dopamine receptors, but requires regular monitoring of white blood cell count.
- Pimavanserin: specifically approved for Parkinson's disease psychosis, targets serotonin rather than dopamine.
From the Research
Antipsychotics to Avoid in Lewy Body and Parkinson's Disease
- Typical antipsychotics are not recommended for patients with Lewy body dementia (LBD) and Parkinson's disease dementia (PDD) due to the high risk of worsening motor symptoms and increasing the risk of mortality 2, 3.
- Some atypical antipsychotics, such as quetiapine, may be used with caution, but their efficacy is equivocal and they may still worsen motor function 3.
- Clozapine has a robust evidence base for treating psychosis in PDD, but its use is limited by the risk of agranulocytosis and the need for frequent blood count monitoring 3.
- Pimavanserin may be a useful treatment option for psychosis in PDD and LBD, but further research is needed to confirm its efficacy and safety in LBD psychosis 4, 3.
Key Considerations
- Cholinesterase inhibitors, such as rivastigmine, galantamine, and donepezil, are effective in managing cognitive and behavioral symptoms in LBD and PDD, and may be a better treatment option than antipsychotics for some patients 2, 4, 5.
- Memantine may also be effective in improving clinical global impression of change in patients with mild to moderate LBD 4.
- Levodopa can treat parkinsonism in some LBD patients, but the dose is often limited due to the risk of worsening visual hallucinations 4.