What is the treatment for sialorrhea in Parkinson's disease?

Treatment of Sialorrhea in Parkinson's Disease

Anticholinergic medications should be used as first-line therapy for sialorrhea in Parkinson's disease, with botulinum toxin injections recommended as second-line therapy for patients with inadequate response or intolerance to anticholinergics. 1

Understanding Sialorrhea in Parkinson's Disease

• Affects 50-60% of Parkinson's patients, with subclinical sialorrhea present in up to 90% 2
• Not caused by increased saliva production but by impaired swallowing, leading to saliva accumulation in the mouth 3
• Mechanisms include:
  • Inability to retain saliva in the oral cavity (hypomimia, involuntary mouth opening)
  • Salivary clearance deterioration (lingual bradykinesia, dysphagia)
  • Declining posture or drooping head 2

Treatment Algorithm

First-Line Treatment: Anticholinergic Medications

1. Oral anticholinergics:

   • Trihexyphenidyl: Start with 1 mg daily, increase by 2 mg increments every 3-5 days until optimal control (typically 6-10 mg daily) 4
   • Take medication with meals to improve tolerance; may be divided into 3-4 doses per day 4
   • Monitor for side effects: dry mouth, constipation, urinary retention, blurred vision, confusion 1

2. Important considerations:

   • For patients taking levodopa, anticholinergics may need dose adjustment as they can interact 4
   • Anticholinergics should be continued only if benefits outweigh side effects 1
   • Patients may require small amounts of atropine as an adjuvant, especially those with excessive salivation 4

Second-Line Treatment: Botulinum Toxin Injections

• Indicated when anticholinergics provide inadequate response or cause intolerable side effects 1
• FDA-approved regimen: IncobotulinumtoxinA (Xeomin) 100 Units injected into parotid and submandibular glands in a 3:2 dose ratio 1
• Benefits include:
  • Simple injection procedure
  • Effects last weeks to months
  • Relatively inexpensive 1
• Common side effects include mild to moderate dry mouth and dysphagia 1

Third-Line Treatment: Radiation Therapy

• Consider for severe, debilitating sialorrhea unresponsive to other treatments
• Should be reserved for use in experienced centers due to risk of irreversible dryness 1

Clinical Monitoring and Considerations

• Sialorrhea increases risk of aspiration pneumonia, which is a leading cause of death in Parkinson's disease 5, 1
• Additional complications include perioral chapping, dehydration, odor, and social stigmatization 6
• For patients experiencing motor fluctuations, consider protein redistribution diet (low protein breakfast/lunch with normal protein dinner) to maximize levodopa absorption and efficacy 5
• Advise patients to take levodopa medications at least 30 minutes before meals to avoid interactions with dietary amino acids 5

Special Considerations

• Regular screening for dysphagia is recommended for all Parkinson's patients with Hoehn & Yahr stage above II or weight loss, low BMI, drooling, dementia, or signs of dysphagia 5
• Treatment of sialorrhea should be part of a comprehensive approach to managing oral and pharyngeal dysfunction in Parkinson's disease
• Avoid abrupt withdrawal of anticholinergic medications as this may exacerbate parkinsonian symptoms 4