Drug-Induced Constipation

Constipation is the most common gastrointestinal (GI) problem in the general population, particularly in older adults.[1] At any given time, approximately one-sixth of adults overall and one-third of adults over age 60 have symptoms of constipation.[2]

Such symptoms include:

• Infrequent bowel movements, typically fewer than three per week;
• Stools that are hard, dry or lumpy;
• Stools that are difficult or painful to pass; and
• A sensation that not all stool has passed

Constipation itself is not a disease but may be a symptom of an underlying medical condition, such as diabetic neuropathy (nerve damage), hypothyroidism or Parkinson’s disease.[3]

Importantly, numerous prescription and over-the-counter drugs can cause or exacerbate constipation. Knowing which medications prescribed or recommended by your doctor cause constipation will allow you to take steps to prevent or minimize this common, troubling adverse drug effect.

How do drugs cause constipation?

Drugs can induce constipation in three major ways:

• Reduced intestinal peristalsis (involuntary rhythmic muscle contractions that propel food through the small intestine and colon), which results in slower passage of food and waste through the GI tract;
• Decreased intestinal secretions of fluid and electrolytes; and
• Increased intestinal reabsorption of fluid and electrolytes.[4]

The latter two mechanisms can result in an overall net decrease in the fluid content of stool, leading to hard and dry stools.

Specific drug categories

The list of constipation-inducing drugs is lengthy and includes aluminum-containing antacids, antihistamines, antipsychotics, beta blockers, calcium channel blockers, diuretics, iron supplements, overactive bladder drugs, Parkinson’s disease drugs, tricyclic antidepressants and opioid analgesics.

Many of these drug categories belong to the much larger family of drugs known as anticholinergics, which block the neurotransmitter (chemical messenger) acetylcholine. Table 1 below lists examples of constipation-inducing anticholinergic medications, and Table 2 below lists examples of constipation-inducing non-anticholinergic drugs. Note that these lists are not all-inclusive.

Table 1. Examples of Anticholinergic Drugs That Cause Constipation

†Combination brand-name drug products excluded
*Designated as Limited Use by Worst Pills, Best Pills News
**Designated as Do Not Use by Worst Pills, Best Pills News

Table 2. Examples of Non-Anticholinergic Drugs That Cause Constipation

†Combination brand-name drug products excluded except for GAVISCON
*Designated as Limited Use by Worst Pills, Best Pills News
**Designated as Do Not Use by Worst Pills, Best Pills News

What You Can Do

Be aware that people can have different bowel-movement patterns, and only you know what’s normal for you.

To prevent or manage constipation due to a medication (or any other reason), increase your dietary fiber intake (such as whole-grain breads and cereals, raw vegetables, raw and dried fruits, and beans); drink plenty of sugar-free, nonalcoholic liquids (six to eight glasses per day); and exercise daily. If your constipation persists, consider a trial of a bulk-forming laxative, such as psyllium (METAMUCIL), for a few days. You should contact your doctor promptly if you experience severe or prolonged constipation.
 

References

[1] Wald A. Etiology and evaluation of chronic constipation in adults. UpToDate. February 26, 2020.

[2] American Gastroenterological Association; Bharucha AE, Dorn SD, Lembo A, Amanda Pressman A. American Gastroenterological Association medical position statement on constipation. Gastroenterology. 2013;144(1):211-217.

[3] Wald A. Etiology and evaluation of chronic constipation in adults. UpToDate. February 26, 2020.

[4] Branch RL, Butt TF. Drug-induced constipation. Adverse Drug React Bull. 2009 August;257:987-990.