What is the best approach to manage constipation in elderly patients?

Management of Constipation in Elderly Patients

Polyethylene glycol (PEG) at 17 g/day is the first-line pharmacological treatment for elderly patients with constipation due to its efficacy, good safety profile, and tolerability. 1, 2

Initial Assessment and Non-Pharmacological Approaches

Before initiating medication, implement these non-pharmacological measures:

• Ensure access to toilets, especially for those with decreased mobility 3, 2
• Provide dietetic support to address nutritional needs 3, 2
• Optimize toileting habits by educating patients to attempt defecation twice daily, preferably 30 minutes after meals, and to strain no longer than 5 minutes 3, 2
• Increase fluid intake if inadequate 3, 2
• Increase dietary fiber if patient has adequate fluid intake and physical activity 3, 4
• Encourage appropriate physical activity when possible 3, 2

Pharmacological Management Algorithm

First-Line Treatment

• Start with PEG 17 g/day, which offers efficacy and tolerability specifically for elderly patients 3, 1, 2
• PEG has demonstrated increased spontaneous bowel movement frequency in clinical trials 5

Second-Line Options

• If PEG is insufficient, add or switch to stimulant laxatives (senna, bisacodyl 10-15 mg daily-TID) with a goal of one non-forced bowel movement every 1-2 days 3, 2
• For patients with opioid-induced constipation, consider methylnaltrexone for opioid-induced constipation (except in post-operative ileus and mechanical bowel obstruction) 3

Third-Line Options

• For persistent constipation, consider adding other laxatives such as:
  • Bisacodyl suppository (one rectally daily-BID) 3
  • Lactulose (30-60 mL BID-QID) 3
  • Sorbitol (30 mL every 2 hours × 3, then as needed) 3
  • Consider lubiprostone for chronic idiopathic constipation if other treatments fail 5

Special Considerations and Precautions

Medications to Use with Caution or Avoid

• Saline laxatives (e.g., magnesium hydroxide) should be used with caution due to risk of hypermagnesemia, especially in patients with renal impairment 3, 2
• Bulk-forming agents should be avoided in non-ambulatory patients with low fluid intake due to increased risk of mechanical obstruction 3, 2
• Liquid paraffin should be avoided in bed-bound patients and those with swallowing disorders due to risk of aspiration lipoid pneumonia 3, 2
• Docusate sodium (stool softener) has limited evidence for efficacy and should not be used as monotherapy 4, 6

For Fecal Impaction

• Administer glycerin suppository with or without mineral oil retention enema 3
• Perform manual disimpaction following pre-medication with analgesic and/or anxiolytic 3
• Use tap water enemas until clear for severe impaction 3
• For patients with swallowing difficulties or repeated fecal impaction, rectal measures (suppositories or enemas) may be preferred, with isotonic saline enemas being safer than sodium phosphate enemas 3, 2

Monitoring and Follow-up

• Individualize laxative regimens based on the older person's medical history, particularly cardiac and renal comorbidities 3, 2
• Monitor for dehydration and electrolyte imbalances, especially in patients with chronic kidney/heart failure 3, 2
• Regular monitoring of chronic kidney/heart failure is necessary when using laxatives with concomitant treatment with diuretics or cardiac glycosides 3
• Reassess for cause and severity of constipation if symptoms persist 3
• Check for impaction or obstruction if constipation continues despite treatment 3

Common Pitfalls to Avoid

• Don't assume increased fluid intake alone will resolve constipation unless there is evidence of dehydration 6
• Don't increase fiber intake in patients with inadequate fluid intake or immobility 3, 6
• Don't use bulk-forming laxatives in patients with opioid-induced constipation 2
• Don't overlook medication-induced constipation - discontinue any non-essential constipating medications 3, 4
• Don't assume stimulant laxatives at recommended doses are harmful to the colon with long-term use 6