Is it reasonable to trial discontinuing levodopa (L-dopa) in patients with advanced Parkinson's disease and Lewy body dementia who are experiencing significant appetite and weakness issues?

Discontinuing Levodopa in Advanced Parkinson's Disease with Lewy Body Dementia

Yes, it is reasonable to trial discontinuation of levodopa in patients with very advanced disease who are experiencing appetite and weakness issues, as these may be medication side effects and the benefits may no longer outweigh the risks in end-stage disease.

Assessment of Appropriateness for Levodopa Discontinuation

When considering levodopa discontinuation in advanced Parkinson's disease with Lewy body dementia, evaluate:

Indicators Supporting Discontinuation:

• Presence of severe or end-stage dementia (dependence in most basic ADLs, limited life expectancy) 1
• Development of intolerable side effects like severe nausea, vomiting, weight loss, anorexia 1
• No clinically meaningful benefit observed during treatment 1
• Clinically meaningful worsening despite treatment over past 6 months 1
• Poor medication adherence that precludes safe use 1

Medication Impact on Nutrition

• Medications frequently affect appetite, with gradual decline from slight changes to more severe loss of appetite 1
• Drug-induced taste and smell disorders and disturbed gastrointestinal motility may contribute to nutritional decline 1
• Polypharmacy has been demonstrated to have a robust association with malnutrition in older populations 1

Discontinuation Protocol

If discontinuation is warranted:

1. Gradual tapering is essential - reduce dose by 50% every 4 weeks until reaching the initial starting dose, then discontinue after 4 weeks at this dose 1

2. Monitor closely for:

   • Worsening of motor symptoms
   • Changes in cognitive function
   • Neuropsychiatric symptoms
   • Overall quality of life

3. Be prepared to reinitiate treatment if the patient shows clinically meaningful worsening of cognition, functioning, neuropsychiatric symptoms, or global assessment related to discontinuation 1

Special Considerations for Lewy Body Dementia

• Only about one-third of DLB patients show significant motor response to levodopa, compared to 57-70% of PD/PDD patients 2
• Younger DLB patients are more likely to respond to dopaminergic treatment 2
• Levodopa should be used at the lowest effective dose to minimize side effects 3
• A common pitfall is discontinuing levodopa completely when partial benefit may still exist 3

Nutritional Management During Medication Changes

• Perform medication review to minimize adverse drug effects on food and fluid intake 1
• Monitor weight, BMI, nutritional status, homocysteine, vitamin B12, folate, and vitamin D levels 3
• Consider protein distribution strategies to optimize medication absorption 3

Alternative Approaches

If appetite and weakness issues persist after levodopa discontinuation:

• Consider cholinesterase inhibitors (particularly rivastigmine) which may help with both cognitive and some neuropsychiatric symptoms 4, 5
• Address any autonomic symptoms with appropriate symptomatic treatments 5
• Encourage shared eating occasions to improve quality of life 1
• Implement individualized rehabilitation treatment for any dysphagia 3

Caution

• Decisions related to discontinuing medications should consider patient preferences (if capable) or prior expressed wishes, in collaboration with family or substitute decision makers 1
• Avoid conventional antipsychotics if psychotic symptoms emerge during discontinuation, as they are often poorly tolerated 4
• Monitor for withdrawal symptoms and be prepared to restart at a lower dose if significant deterioration occurs

Remember that the goal is to optimize quality of life and reduce medication burden when the disease is very advanced and benefits no longer outweigh side effects.