What is the treatment regimen for Parkinson's disease?

Treatment Regimen for Parkinson's Disease

Levodopa/carbidopa is the most effective medication for treating Parkinson's disease and should be the first-line treatment for most patients, with strategies to maximize its effectiveness including proper timing of medication and protein redistribution for patients experiencing motor fluctuations. 1

Initial Treatment Approach

• Levodopa combined with a dopa-decarboxylase inhibitor (carbidopa) is the most potent dopaminergic therapy for Parkinson's disease 2
• For early Parkinson's disease, treatment depends on symptom severity; if greater symptomatic effect is required, levodopa or dopamine agonists are usually the drugs of choice 3
• The ability to remain employable or physically active is an important goal in younger patients; therefore, in some instances, levodopa initiation should be considered early on 2

Optimizing Levodopa Administration

• Take levodopa medications at least 30 minutes before meals to avoid interactions with dietary proteins that reduce absorption and efficacy 4, 1
• Implement protein redistribution diet (low-protein breakfast and lunch, with normal protein intake at dinner) to improve motor function and increase "ON" time 1
• Monitor for potential complications of protein redistribution including weight loss, micronutrient deficits, hunger before dinner, and dyskinesias 1
• Levodopa may cause hyperhomocysteinemia, especially in older patients and those with long-standing disease, requiring vitamin B supplementation to maintain normal homocysteine levels 4, 1

Managing Motor Complications

• For patients with troublesome dyskinesias, reducing levodopa doses may be considered 1
• Dosage reduction of levodopa is recommended if dyskinesia or hallucinations develop 5
• Consider adding a catechol-O-methyltransferase inhibitor (entacapone) to improve levodopa bioavailability, especially when used with a dopa-decarboxylase inhibitor 2
• Triple combination of levodopa/carbidopa/entacapone available in a single tablet offers flexibility and helps control response fluctuations 2

Adjunctive Therapies

• Dopamine agonists like pramipexole can be effective as monotherapy in early Parkinson's disease or as adjunct therapy with levodopa in advanced disease 5
• Pramipexole has shown efficacy in reducing "off" hours per day when used as an adjunct to levodopa therapy 5
• Rasagiline (1 mg/day) has demonstrated effectiveness as both monotherapy in early Parkinson's disease and as adjunct therapy to dopamine agonists or levodopa 6
• For advanced Parkinson's disease with motor fluctuations, consider deep brain stimulation (DBS) of either subthalamic nucleus (STN) or globus pallidus internus (GPi) 1

Special Considerations for REM Sleep Behavior Disorder (RBD) in PD

• Clonazepam is commonly used to treat RBD in Parkinson's disease, but side effects include morning sedation, gait imbalance/falls, depression, and cognitive disturbances 7
• Melatonin (starting at 3 mg and increasing by 3-mg increments to 15 mg) is a good option for older patients and those with neurodegenerative disease because it is only mildly sedating 7
• Rivastigmine may be appropriate for patients with RBD and cognitive impairment refractory to other treatments 7
• Deep brain stimulation of the subthalamic and globus pallidus interna nuclei has not demonstrated improved control of dream enactment among PD patients with RBD 7

Nutritional and Swallowing Management

• Monitor for side effects of PD medications that might influence nutritional status, including nausea, vomiting, abdominal pain, dyspepsia, constipation, weight decrease, dry mouth, and anorexia 7
• Optimization of antiparkinsonian treatment should be advised to ameliorate motor symptoms that contribute to dysphagia in PD patients 7
• Patients with constipation may benefit from fermented milk with probiotics and prebiotic fiber, in addition to increased water and fiber intake 4

Common Pitfalls and Caveats

• Avoid strict low-protein diets as they are not supported by evidence 1
• For tube-fed patients on oral levodopa, interrupt enteral nutrition for at least 1 hour before and 30-40 minutes after medication administration 1
• Increasing doses of levodopa over time are associated with higher risk for malnutrition, requiring careful monitoring 7, 1
• The clinical use of levodopa may eventually be limited by the development of treatment-related complications, including response fluctuations, dyskinesia, and psychiatric problems 2