What are the treatment options for chronic constipation in a patient with Amyotrophic Lateral Sclerosis (ALS)?

Treatment Options for Chronic Constipation in ALS Patients

For patients with ALS suffering from chronic constipation, a stepwise approach starting with polyethylene glycol (PEG) is recommended as first-line therapy, followed by stimulant laxatives as needed, with dietary modifications as supportive measures throughout treatment. 1, 2

First-Line Treatment

Osmotic Laxatives

• Polyethylene glycol (PEG) is strongly recommended as the first-line pharmacological treatment 1, 3
  • Has demonstrated durable response over 6 months
  • Start with standard dosing and titrate as needed
  • Side effects include abdominal distension, loose stool, flatulence, and nausea
  • Can be combined with fiber supplements for enhanced effect

Dietary Modifications (as supportive measures)

• Fiber supplementation:

  • Psyllium is the most effective fiber supplement 1, 4
  • Recommended dose: >10g/day for at least 4 weeks for optimal effect 4
  • Ensure adequate hydration when using fiber supplements 1
  • Be aware that flatulence is a common side effect 1, 4

• Fluid intake:

  • Increase water consumption throughout the day 2
  • Consider mineral water rich in magnesium and/or bicarbonate 5

• Meal patterns:

  • Fractionate meals for patients with muscular fatigue 1
  • Consider fermented milk products containing probiotics and prebiotic fiber 1, 2

Second-Line Treatment

Stimulant Laxatives

• Bisacodyl or sodium picosulphate 1, 2
  • Recommended for short-term use (daily use for 4 weeks or less) or as rescue therapy
  • Bisacodyl 10-15 mg, 2-3 times daily
  • Target: one non-forced bowel movement every 1-2 days
  • Can be used as occasional rescue therapy in combination with other agents

Additional Osmotic Options

• Magnesium oxide 1, 2

  • Start at lower dose and increase if necessary
  • Avoid in patients with renal insufficiency due to risk of hypermagnesemia
  • Effective for short-term use (4 weeks), though longer-term use is likely appropriate

• Lactulose 1, 2

  • Consider for patients who fail or cannot tolerate other therapies
  • Be aware that bloating and flatulence are common dose-dependent side effects

Management of Refractory Constipation

For Severe Cases

• Rectal bisacodyl once daily 2
• Glycerin suppositories for impaction 2
• Manual disimpaction may be necessary in severe cases 2

Advanced Options

• Lubiprostone (activates chloride channels to enhance intestinal fluid secretion) 2
• Linaclotide (agonist of guanylate cyclase-C receptors) 2
• Neostigmine may be considered in cases of acute colonic pseudo-obstruction 6

Important Considerations

Disease Impact

• Constipation in ALS is associated with faster disease progression and reduced survival rates 7
• Prevalence increases from approximately 33% before diagnosis to 65% after diagnosis 8

Monitoring and Adjustment

• Assess for treatable causes of constipation (hypercalcemia, hypokalemia, hypothyroidism, diabetes mellitus, medication side effects) 2
• Rule out impaction or obstruction before escalating therapy 2
• Monitor response to treatment and adjust as needed based on symptom control and side effects

Cautions

• Avoid magnesium preparations in patients with renal insufficiency 1
• Be aware that stool softeners like docusate 9 are not specifically recommended in ALS guidelines but may be considered as adjunctive therapy

By following this stepwise approach and monitoring response to treatment, chronic constipation in ALS patients can be effectively managed, potentially improving quality of life and possibly affecting disease progression.