Laxatives

  • Treatment
  • Docusate ≥ Bisacodyl ≥ fleet enema?
  • Opioid-Induced
    • Methylnaltrexone
    • Mu opioid receptor (PAM-OR) antagonist
  • Post-op ileus
    • Alvimopan
    • Mu opioid receptor (PAM-OR) antagonist
    • Quaternary amine unlike methylnaltrexone, peripherally acting
  • Correct potassium
  • Bulk-forming Agents
  • MOA: add bulk and water to stools, better for long-term maintenance
  • Site: Small and Large intestines
  • Onset: 12-72 hours
  • Metamucil
  • Citrucel
  • Wheat Bran
  • Flaxseeds
  • Psyllium seed husk
    • Promotes peristalsis
  • Emollient Agents (Stool Softeners)
  • MOA: Anionic surfactants that incorporate water and fats into the stool
  • Notes: Prevent constipation rather than treating it
  • Site: Small and Large intestines
  • Onset: 12-72 hours
  • Docusate (Colace, Diocto)
  • Lubricant Agents
  • MOA: Decrease colonic absorption of water, increase weight
  • Site: Colon
  • Onset: 6-8 hours
  • Mineral Oil
  • Osmotic Agents
  • MOA: cause the intestines to hold more water, stimulates movement
  • Site: Colon
  • Onset: 12-72 hours oral, 25 mins – 1 hour rectal
  • Polyethylene Glycol (Miralax, Colyte, Golytely, Glycolax)
    • Used for bowel prep, whole bowel irrigation
    • Better than lactulose
  • Magnesium Salts (Milk of Magnesia)
  • Lactulose
    • Osmotic effect, lowers pH, decreases intestinal ammonia absorption
  • Sorbitol (Enema)
  • Mannitol (Enema)
  • Prokinetic Agents
  • Prucalopride
  • Saline Laxative Agents
  • Site: Small and large intesitnes
  • Onset: 30mins too 3 hours oral, 2-15 minutes rectal
  • Sodium Bisulfate
  • Sodium Phosphate
  • Magnesium Hydroxide
  • Magnesium Sulfate (Epsom Salt)
  • Stimulant Agents
  • Site: Colon
  • Onset: 6-10 hours
  • Senna
  • Sodium Pocosulfate
  • Bisacodyl (Dulcolax)
  • SE: Loss of haustral folds with chronic use (melanosis coli)
  • Add Osmotic laxative or docusate if not working
  • Other
  • Castor Oil
  • Secretagogues (Chloride Channel Activators)
  • Linaclotide
  • Plecanatide
  • Lubiprostone