How to manage delusions of infidelity in a patient with early-onset Parkinson's Disease on levodopa, anticholinergics, pramipexole, and other medications?

Management of Delusions of Infidelity in Early-Onset Parkinson's Disease

Quetiapine is the preferred antipsychotic for managing delusions of infidelity in this Parkinson's disease patient, starting at 25 mg immediate release orally at bedtime with careful titration. 1

Assessment and Medication Review

• First, evaluate if pramipexole (Pramirol) is contributing to the delusions, as dopamine agonists are known to cause neuropsychiatric complications including hallucinations and delusions 2
• Review the current medication regimen, particularly focusing on the dose and timing of pramipexole, which may need to be reduced or discontinued 2
• Assess for other potential causes of delusions including metabolic disturbances, infections, or other medication side effects 1

Pharmacological Management

First-Line Approach:

• Quetiapine is the preferred antipsychotic for Parkinson's disease patients with psychosis:
  • Starting dose: 25 mg immediate release orally at bedtime 1
  • Can be given every 12 hours if scheduled dosing required 1
  • Advantages: Less likely to cause extrapyramidal symptoms than other antipsychotics and has sedating properties 1
  • Use lower doses in older patients and those with hepatic impairment 1

Alternative Options:

• Olanzapine may be considered if quetiapine is ineffective:

  • Starting dose: 2.5-5 mg orally at bedtime 1
  • Caution: May cause drowsiness and orthostatic hypotension 1
  • Available as orally disintegrating tablet for easier administration 1

• Aripiprazole can be considered as a third option:

  • Starting dose: 5 mg orally daily 1
  • Less likely to cause extrapyramidal symptoms 1

Important Cautions:

• Avoid haloperidol and other first-generation antipsychotics as they should not be used in patients with Parkinson's disease due to high risk of worsening motor symptoms 1
• Avoid risperidone due to increased risk of extrapyramidal symptoms at doses above 6 mg/24 hours 1
• Use antipsychotics at the lowest effective dose and for the shortest period possible 1

Non-Pharmacological Interventions

• Provide reorientation and cognitive stimulation regularly 1
• Implement good sleep hygiene practices 1
• Reduce or eliminate any medications with anticholinergic properties that may be contributing to delirium/psychosis 1
• Educate family members about the nature of delusions in Parkinson's disease to reduce distress and improve understanding 1
• Provide written information about psychosis in Parkinson's disease to family members 1

Monitoring and Follow-up

• Monitor for:
  • Response to antipsychotic therapy
  • Worsening of Parkinson's motor symptoms
  • Sedation and orthostatic hypotension 1
  • Other side effects including metabolic effects with long-term use 1
• Adjust medication doses based on response and side effects
• Consider psychiatric consultation for refractory symptoms 1

Special Considerations

• Delusions in Parkinson's disease often result from dopaminergic medication side effects, particularly dopamine agonists like pramipexole 2
• The management approach must balance control of psychotic symptoms with maintaining adequate control of motor symptoms 1
• If delusions persist despite medication adjustments, consider reducing levodopa (Syndopa) dose if motor symptoms allow 1

Remember that pharmacological interventions should be limited to patients with distressing symptoms or when there are safety concerns, and medications should be used at the lowest effective dose for the shortest time possible 1.