Treatment for Parkinson's Medication-Induced Constipation
Understanding Constipation in Parkinson's Disease
- Neurodegenerative processes affecting the enteric nervous system contribute to constipation in Parkinson's disease patients 1, 2
- Side effects of PD medications, particularly dopamine agonists and anticholinergics, can cause constipation in Parkinson's disease patients 1, 2
- Reduced physical activity due to motor impairment is a factor in constipation in Parkinson's disease patients 1
- Pelvic floor dyssynergia is a cause of constipation in Parkinson's disease patients 1, 2
First-Line Treatment Approach
Non-Pharmacological Interventions
- Increasing fluid intake can improve colonic transit in Parkinson's disease patients with constipation 1, 2
- Increasing dietary fiber intake is recommended for Parkinson's disease patients with constipation, if adequate fluid intake and physical activity are possible 1, 3
- Encouraging physical activity is beneficial for Parkinson's disease patients with constipation 3, 4
- Daily consumption of fermented milk containing probiotics and prebiotic fiber can increase complete bowel movements, improve stool consistency, and reduce laxative use in Parkinson's disease patients with constipation 1, 2
Pharmacological Interventions
First-Line Medications
- Polyethylene glycol (PEG) 17g with 8 oz water twice daily is a recommended first-line treatment for constipation in Parkinson's disease patients 3, 5, 4
- Stimulant laxatives, such as bisacodyl 10-15 mg daily to TID, can be used to achieve one non-forced bowel movement every 1-2 days in Parkinson's disease patients with constipation 3, 5, 2
- Senna can be used as a stimulant laxative for constipation in Parkinson's disease patients, starting at a lower dose and increasing as needed 5, 6
Second-Line Treatment Options
- Magnesium oxide can be used as a second-line treatment for constipation in Parkinson's disease patients, starting at a lower dose and increasing as necessary 5, 6
- Lactulose can be used for patients who fail or are intolerant to OTC therapies, but may cause bloating and flatulence as dose-dependent side effects 5, 6
- Prokinetic agents, such as metoclopramide 10-20 mg PO QID, can be considered for severe cases of constipation in Parkinson's disease patients 3
Treatment Algorithm for Refractory Cases
- Ruling out impaction or obstruction through physical exam and abdominal x-ray is necessary for refractory constipation in Parkinson's disease patients 3
- Glycerine suppository or mineral oil retention enema can be considered for refractory constipation in Parkinson's disease patients 3
- Methylnaltrexone 0.15 mg/kg subcutaneously every other day can be considered for severe cases of refractory constipation in Parkinson's disease patients, except in cases of post-op ileus and mechanical bowel obstruction 3, 4