From the Guidelines
For an agitated, delirious patient with Parkinson's disease, I would consider quetiapine as the first-line antipsychotic medication, starting at a low dose of 25mg and titrating carefully as needed, as it has a lower risk of worsening parkinsonian symptoms compared to other antipsychotics 1.
Medication Options
- Quetiapine: 25 mg orally, titrating carefully as needed, due to its sedating effects and lower risk of extrapyramidal side effects (EPSEs) 1
- Aripiprazole: 5 mg orally or intramuscularly, as it is less likely to cause EPSEs, but may cause headache, agitation, anxiety, insomnia, dizziness, and drowsiness 1
Important Considerations
- Avoid using first-generation antipsychotics like haloperidol, as they can severely worsen motor function in patients with Parkinson's disease due to their strong dopamine blockade 1
- Benzodiazepines like lorazepam (0.5-1mg) may be used cautiously for severe agitation, but they can worsen confusion and have a risk of falls, especially in older or frail patients 1
- Identify and treat underlying causes of delirium, such as infections, metabolic disturbances, or medication effects
- Continue the patient's regular Parkinson's medications to prevent worsening motor symptoms, which can exacerbate delirium
Non-Pharmacological Approaches
- Implement reorientation strategies, ensuring adequate sleep, maintaining hydration, and creating a calm environment to manage agitation and delirium
- Use non-pharmacological interventions as first-line treatment, reserving medications for patients with distressing delirium symptoms or safety concerns 1
From the Research
Medications for Agitated, Delirious Patients with Parkinson's Disease
- Atypical antipsychotics can be used to treat psychosis in patients with Parkinson's disease without compromising motor function 2
- The choice of atypical antipsychotic is largely based on ease of use and adverse effect profile, as most have comparable efficacy in improving psychosis 2
- Medications that can be considered for agitated, delirious patients with Parkinson's disease include:
- Clozapine: does not induce deterioration of motor function, but has the potential to cause agranulocytosis 2
- Quetiapine: well-tolerated and effective in controlling psychosis, with common adverse effects including sedation and orthostatic hypotension 2, 3, 4, 5
- Dexmedetomidine: can be used to manage acute delirium in patients with Parkinson's disease, especially in the hospital setting 6
- Other atypical antipsychotics, such as risperidone and olanzapine, may also be considered, but their use is limited due to potential adverse effects on motor function 2
- Cholinesterase inhibitors and ondansetron have also been reported to alleviate psychosis in Parkinson's disease, but their use is not as well-established as that of atypical antipsychotics 2