Many of you know that Opiates, non steroidal anti-inflammatory drugs, and other drugs, are associated with constipation. Constipation can become a bigger struggle for you than the illness that led you to take the medications. Why does this happen? And what works and what doesn't for treatment of medication induced constipation?
Why does this happen?
Opioids and other medications affect all segments of the stomach and intestine (particularly the colon) altering nerve input to the GI tract which inhibits movement. Additionally, opiates may increase the absorption of electrolytes and water (making harder drier poops), increase anal sphincter tone and reduce sensitivity to the presence of stool. All of these factors contribute to constipation and hard stools. And misery.
What doesn't work?
Fiber and Bulk Laxatives (psyllium, bran, Citrucel, etc.) are generally not effective for the treatment of drug-induced constipation. Period.
What does work?
Stimulant Laxatives: Senna and Bisacodyl (Dulcolax) increase intestinal motility and help with the efflux of water INTO the bowel which improves constipation. SENNA is more commonly used and slightly more effective than BISACODYL (Dulcolax) for opioid-induced constipation.
Osmotic Laxatives: These include Magnesium or Phosphate-containing laxatives and nonabsorbable sugars (Lactulose, Sorbitol, Glycerin) and polyethylene glycol (Miralax). They work by increasing fluid accumulation in the colon and small intestine which improves constipation. These are effective for treatment of opiate induced constipation. Some data show that lactulose is better than sorbitol and that Miralax is better than lactulose.
Emollient Laxatives: These include Colace (Docusate), or mineral oil. However, they are inferior to the osmotic and stimulant laxatives when used for the treatment of drug induced constipation.
Any new options?
Yes--Methylnaltrexone (Relistor) is the newest medication found in recent studies to provide good relief of opioid-induced constipation in terminally ill patients who do not respond to laxatives. Relistor is a subcutaneous injection and represents an important therapeutic option for patients with advanced illness who are suffering from opioid-induced constipation.
I hope this helps.