What is the cheapest medication for treating chronic constipation?

Cheapest Medications for Chronic Constipation

For chronic constipation treatment, the cheapest effective medications are polyethylene glycol, milk of magnesia, psyllium fiber, and bisacodyl/senna, all costing approximately $1 or less per day. 1

First-Line Options (Under $1/day)

Bulk-Forming Agents

• Psyllium (Metamucil): 15g daily
  • Cost: Less than $1/day
  • Mechanism: Soluble fiber that traps water in intestine
  • Caution: Ensure adequate hydration to prevent intestinal obstruction 2
  • Side effects: Bloating, abdominal discomfort

Osmotic Laxatives

• Polyethylene glycol (PEG): 17g daily

  • Cost: $10-$45/month ($0.33-$1.50/day) 1
  • Mechanism: Osmotic laxative
  • Advantage: Durable response over 6 months
  • Side effects: Bloating, abdominal discomfort, cramping

• Milk of Magnesia: 1 oz twice daily

  • Cost: Less than $1/day 1
  • Mechanism: Osmotic laxative
  • Caution: Use carefully in renal insufficiency 3

• Lactulose: 15g daily

  • Cost: Less than $50/month 1
  • Mechanism: Osmotic laxative
  • Note: Only osmotic agent studied in pregnancy
  • Side effects: Bloating and flatulence

Stimulant Laxatives

• Bisacodyl: 5mg daily

  • Cost: Less than $50/month (often less than $1/day) 1
  • Maximum dose: 10mg daily
  • Best used: 30 minutes after meals to synergize with gastrocolonic response 1
  • Side effects: Cramping, abdominal discomfort

• Senna: 8.6-17.2mg daily

  • Cost: Less than $50/month 1
  • Side effects: Similar to bisacodyl
  • Note: Also present in many laxative teas

Treatment Algorithm

1. Start with lifestyle modifications:

   • Adequate fluid intake (at least 2L daily)
   • Increased dietary fiber (aim for 25g daily)
   • Regular physical activity
   • Optimized toileting schedule (attempt defecation 30 minutes after meals)

2. First-line pharmacological treatment:

   • Begin with fiber supplementation (psyllium 15g daily) and/or
   • Osmotic laxative (PEG 17g daily or milk of magnesia 1 oz twice daily)

3. If inadequate response:

   • Add stimulant laxative (bisacodyl 5mg or senna 8.6-17.2mg daily)
   • Administer 30 minutes after meals for best effect

4. For refractory cases:

   • Consider newer agents only if symptoms don't respond to above treatments:
     • Lubiprostone: $374/month 1
     • Linaclotide: $523/month 1
     • Plecanatide: $526/month 1
     • Prucalopride: $563/month 1

5. For suspected defecatory disorders:

   • Refer for anorectal testing
   • Consider biofeedback therapy (effective in >70% of defecatory disorders) 1

Special Considerations

• Elderly patients: PEG 17g daily is recommended due to favorable safety profile 3
• Renal insufficiency: Avoid magnesium-based products 3
• Pregnancy: Lactulose is the only osmotic agent studied in pregnancy 1
• Defecatory disorders: Biofeedback therapy is more effective than laxatives 1

Common Pitfalls

• Inadequate fluid intake with fiber supplements: Can worsen constipation or cause obstruction 2
• Overuse of stimulant laxatives: May cause electrolyte imbalances and dependence
• Failure to recognize defecatory disorders: Requires specific testing and treatment
• Premature escalation to expensive medications: Try inexpensive options first with proper dosing and duration

Remember that for most patients with chronic constipation, inexpensive options (under $1/day) are effective when used appropriately, making them the most cost-effective first-line treatments.