Constipation is infrequent stools or difficult to pass stools. Medications, specifically pain medications, are the biggest culprit, with opiates (Vicodin, Norco, Tylenol with codeine, etc.) and nonsteroidal anti-inflammatory drugs (NSAIDS) leading the pack. Constipation can become a more significant struggle for you than the illness that led you to take the medications and will make any post-operative course miserable. Why does this happen, and what works for the treatment of medication-induced constipation?
Which medications commonly cause constipation?
- NSAIDS. Ibuprofen, Motrin, Aleve, Advil
- Antihistamines: Benadryl, Claritin (Lortadine) and Allegra for allergies
- Tricyclic antidepressants: Amitriptyline, Nortriptyline.
- Overactive bladder medications: Ditropan (Oxybutynin)and Detrol (Tolterodine)
- Iron supplements
- Opioid pain relievers
- Calcium channel blockers like diltiazem and verapamil
- beta-blockers (drugs ending in “–ol” like atenolol)
- Ondansetron (Zofran). While these work very well for nausea, they commonly result in constipation.
Why do some medications cause constipation?
Opioids and other medications affect parts of the stomach and intestine (particularly the colon), altering nerve input to the gastrointestinal tract, inhibiting movement. Opiates also increase the absorption of electrolytes and water (making drier and thus harder poops), increase anal sphincter tone and reduce sensitivity to the presence of stool. These factors lead to constipation, hard stools, and misery.
What helps for constipation from medications?
First, try dietary modifications with increased fiber (fresh fruit, fresh vegetables, legumes, and whole grains).
Osmotic Laxatives: These include polyethylene glycol (Miralax) and Magnesium or Phosphate-containing laxatives, and non-absorbable sugars (Lactulose, Sorbitol, Glycerin). Osmotic laxatives work by increasing fluid accumulation in the colon and small intestine, which improves constipation. Some evidence shows that lactulose is better than sorbitol, and Miralax is better than lactulose. Hmmm, so is Miralax the best?
Stimulant Laxatives: Senna (Senokot) and Bisacodyl (Dulcolax) increase intestinal motility and help with water flow INTO the bowel, which improves constipation. SENNA is more commonly used and slightly more effective than BISACODYL (Dulcolax) for opioid-induced constipation, and both are over the counter and cheap.
Emollient Laxatives: These include Colace (Docusate) or mineral oil. Know that emollient laxatives are inferior to the osmotic and stimulant laxatives for the treatment of medication-induced constipation. So, this should be your third choice.
If laxatives don’t provide you enough relief, there are newer options, but they are expensive and may require prior authorization and fight by your doctor.
The newest meds for constipation:
The secretagogues: Lubiprostone (Amitiza) is your next choice, followed by Linzess (linaclotide) or Trulance (plecanatide).
The last resort for opioid-induced constipation is Methylnaltrexone (Relistor), an injection, along with other options in this class Movantik (naloxegol) or Symproic (naldemedine).
What doesn’t work for medication induced constipation?
Fiber and Bulk Laxatives (psyllium, Metamucil, bran, fibercon, Citrucel, etc.) are generally ineffective for treating drug-induced constipation. Don’t go there.
I am a Clinical Associate Professor of Medicine at the Keck School of Medicine of USC and a board-certified Internal Medicine physician. For 20 years I’ve had an active private practice in general internal medicine currently at The Doctors of USC Beverly Hills. I am lucky to spend part of my time as the attending physician for medical students and residents during their rotations at LAC+USC Medical Center. I’ve been a medical advisor on leading health social networking sites including Dailystrength.org and Sharecare and currently serve as the medical advisor and blogger for GoodRx.com, a prescription drug price comparison website, and GoodRx care powered by Hey Doctor.
My philosophy of care centers around seeing things we can see coming, and nailing them head-on. I appreciate the idea of sharing power and responsibility for the choices one makes for prevention, treatment, and investigation into medical problems. My hope is to write blog posts to empower patients to navigate their own health by laying out the ways that medicine can guide you with strategies to investigate, prevent, and treat some common medical issues, big and small.
I have appeared on The Doctors, Fox Sports West, The Ricki Lake Show, as well as many local news outlets and have been featured in numerous online and print publications. I am a fellow of the American College of Physicians and honored to be named “Top Doctor” in Los Angeles and Pasadena Magazine for years.