What is the preferred treatment for constipation in older adults, MiraLAX (polyethylene glycol) or senna?

Management of Constipation in Older Adults: MiraLAX vs. Senna

Polyethylene glycol (MiraLAX) is the preferred first-line treatment for constipation in older adults due to its efficacy, good safety profile, and tolerability, while senna should be considered as a second-line option when PEG is insufficient. 1

First-Line Treatment: Polyethylene Glycol (MiraLAX)

• PEG (17 g/day) offers an efficacious and tolerable solution for elderly patients with an excellent safety profile 2, 1
• PEG has demonstrated long-term safety and efficacy for treating constipation in adult and elderly patients for periods up to 12 months, with no evidence of tolerance development 3
• PEG works as an osmotic laxative that draws water into the colon, softening stool and increasing bowel movements 4
• PEG does not require increased fluid intake, making it particularly suitable for older adults who may have difficulty maintaining adequate hydration 1, 5

Second-Line Treatment: Stimulant Laxatives (Senna)

• Stimulant laxatives like senna can be used when osmotic laxatives like PEG are insufficient 2, 1
• When using senna, be aware of potential side effects including abdominal pain and cramps 2, 1
• Stimulant laxatives are generally recommended for intermittent treatment rather than continuous use 6
• Senna works by stimulating intestinal contractions and is effective but may cause more discomfort than PEG 4

Treatment Algorithm for Constipation in Older Adults

1. Start with PEG 17g daily 2, 1

   • Can be increased to higher doses (up to 34g) if needed for more rapid relief 7
   • Monitor for adequate response within 2-3 days

2. If inadequate response to PEG alone:

   • Add or switch to stimulant laxative (senna) 2, 1
   • Use lowest effective dose to minimize cramping

3. For fecal impaction:

   • Use rectal measures (suppositories or enemas) as first-line therapy 2
   • Isotonic saline enemas are preferable in older adults due to fewer adverse effects 2

Special Considerations in Older Adults

• Renal impairment: PEG is safer than magnesium-based laxatives, which should be used with caution due to risk of hypermagnesemia 2, 4

• Cardiac conditions: Regular monitoring is necessary when using laxatives with concomitant treatment with diuretics or cardiac glycosides 2

• Mobility issues: Non-ambulatory patients should avoid bulk-forming agents due to risk of mechanical obstruction 2

• Swallowing difficulties: Avoid liquid paraffin due to risk of aspiration pneumonia 2

• Opioid-induced constipation: Both PEG and senna can be used, but PEG may be more effective and comfortable 2, 1

Prevention Measures to Implement Alongside Medication

• Ensure access to toilets, especially for those with decreased mobility 2, 1
• Provide dietetic support to address nutritional needs 2, 1
• Optimize toileting habits by educating patients to attempt defecation twice daily, preferably 30 minutes after meals 2, 1
• Encourage physical activity within the patient's capabilities 4

Monitoring and Follow-up

• Individualize laxative regimens based on medical history, particularly cardiac and renal comorbidities 2, 1
• Monitor for dehydration and electrolyte imbalances, especially in patients with chronic conditions 2
• Assess response to treatment regularly and adjust as needed 1, 4