Constipation Drugs

Background

At any one time, about 35 to 45 million people in the U.S. have constipation or a related condition called irritable bowel syndrome (IBS). A variety of treatments are available over-the-counter and by prescription, including fiber supplements, stool softeners, and laxatives. The vast majority of people will get the help they need from lifestyle changes and inexpensive nonprescription drugs.

To help you and your doctor choose the right constipation medicine if you need one, Consumer Reports has evaluated the drugs in this category based on their effectiveness, safety, and cost. This brief is a summary of a 17-page report you can access on the Internet at CRBestBuyDrugs.org. You can also learn about other drugs we’ve analyzed on this free Web site. Our independent evaluations are based on scientific reviews conducted by the Oregon Health and Science University-based Drug Effectiveness Review Project. Grants from the Engelberg Foundation and the National Library of Medicine help fund Consumer Reports Best Buy Drugs. These materials were made possible by a grant from the state Attorney General Consumer and Prescriber Education Grant Program, which is funded by the multi-state settlement of consumer fraud claims regarding the marketing of the prescription drug Neurontin (gabapentin).

Do You Need a Constipation Drug?

Most people who have occasional constipation don’t need a drug. Dietary changes, and especially eating more fiber-rich foods—such as vegetables, fruits, whole grains, legumes, and beans—usually resolve the problem. If that doesn’t work, try a fiber supplement. Our analysis found that those containing psyllium are best. However, if your constipation persists for 14 days or longer with fewer than three bowel movements a week, you may need to take a drug.

Common Causes of Constipation

Diet low in fiber—Fiber makes stools softer, bulkier, and easier to pass. Foods high in fiber include fruits, vegetables, beans, legumes and whole grains.

Pregnancy—Constipation is a common problem for women during and after pregnancy. About half develop it. Natural increases in the hormones estrogen and progesterone, as well as increased pressure on a mother’s bowels from carrying the baby, can affect regularity in passing stools.

Age—Constipation is more common in older people. This occurs, in part, because slowing of bowel functions is a natural part of the aging process. The elderly are also more likely to be on medications that slow the gastrointestinal tract.

Changes in routine—Many people become constipated while traveling, especially when it involves large time zone differences. Whether for business or pleasure, travel can disrupt your regular eating and sleeping habits, physical activity levels, and toilet routines. These changes can affect your overall metabolism and result in constipation.

Medicines—Constipation is a common side effect of many prescription and over-the-counter drugs. Some prescription medications commonly known to cause constipation include pain killers, antidepressants, high blood pressure pills, and drugs to treat Parkinson’s Disease.

Our Recommendations

Like headaches and colds, almost everyone will experience a bout of constipation at some point. For most people, these episodes are brief and usually don’t require medical treatment. But doctors start to get concerned if the frequency of your bowel movements drops below three per week for two weeks or longer.

If that happens, you may need to take a medicine. Our evaluation—taking cost and the evidence for effectiveness and safety into account—found the nonprescription drug polyethylene glycol (MiraLax) to be your best initial bet and Best Buy. It improves constipation symptoms, is just as effective as a prescription drug called lactulose, and has a solid track record of being safe and well-tolerated by most people.

We caution against the long-term use (beyond a few days) of the laxatives senna (Senokot, Ex-Lax) and bisacodyl (Correctol, Doxidan, Dulcolax). Studies indicate these drugs are less effective for relieving chronic constipation.

If you’re unable to tolerate MiraLax or it doesn’t improve your symptoms, talk to your doctor about generic lactulose or lubiprostone (Amitiza). Warning: Amitiza is a new and expensive prescription drug which may be no more effective than MiraLax or lactulose for most people, and its safety profile is not fully established.

Amitiza is also approved for women who have IBS with constipation as the main symptom (and many doctors will prescribe it for men, too). But we advise people with this condition to talk to their doctors about trying other medicines first.

This information was released in December 2008.

Cost Comparison

Generic Name and Form*

Brand Name(s)1

Number of Units per Day2

OTC or Rx?3

Cost4

Longer-Term Use—Monthly Cost5

Docusate capsule 50 mg

Generic

One to Three

OTC

$6-$18

Docusate capsule 50 mg

Colace

One to Three

OTC

$10-$30

Docusate capsule 100 mg

Generic

One to Three

OTC

$3-$9

Docusate capsule 100 mg

Phillips

One to Three

OTC

$6-$18

Docusate capsule 240 mg

Generic

One

OTC

$4

Docusate capsule 240 mg

Kaopectate

One

OTC

$13

Lactulose powder 10 g

Kristalose

Two to Three

Rx

$55-$82

Lactulose powder 20 g

Kristalose

One

Rx

$80

Lactulose solution 10 g

Generic

Two to Three

Rx

$40-$60

Lactulose solution 10 g

Enulose, Generlac, others

Two to Three

Rx

$40-$60

Lubiprostone capsule 8 mcg

Amitiza

Two

Rx

$220-$294

Lubiprostone capsule 24 mcg

Amitiza

Two

Rx

$190-$298

Polyethylene glycol powder 17 g

MiraLax

One

OTC

$23

Polyethylene glycol powder 17 g

Glycolax

One

Rx

$39

Polyethylene glycol powder 17 g

Generic

One

Rx

$39

Short-Term Use Only—Per Episode Cost6

Bisacodyl tablet 5 mg

Generic

One to Three

OTC

$1-$2 or less

Bisacodyl tablet 5 mg

Dulcolax, Ex-lax Ultra Strength

One to Three

OTC

$1-$2 or less

Senna tablet 15 mg

Generic

Two to Four

OTC

$1-$2 or less

Senna tablet 15 mg

Senokot, Ex-Lax

Two to Four

OTC

$1-$2 or less

Senna tablet 25 mg

Generic

Two to Four

OTC

$1-$2 or less

Senna tablet 25 mg

Ex-Lax Maximum Strength

Two to Four

OTC

$1-$2 or less

In Hospital or Special Use—Monthly Cost7

Alvimopan capsule 12 mg

Entereg

Two

Rx

$950

Methylnaltrexone injection 12 mg

Relistor

8-12 mg every 2 days

Rx

$569-$1,037

Tegaserod tablet 6 mg8

Zelnorm

Two

Rx

Not available

* Selected doses are listed due to space limitations. Not all brands or branded generics (of which there are many) are included. For a more complete listing, see our full report at CRBestBuyDrugs.org.

1. “Generic” means this row lists the price for the generic version of this medicine.

2. "Unit" refers to pill, liquid, injected, or powdered dose. As recommended.

3. "OTC" stands for “over-the-counter,” meaning the drug on this row is available without a prescription. “Rx” means the drug on this row is available by prescription only.

4. Prices are from multiple sources since many of these drugs are available without a prescription. Among those sources are online pharmacies and pharmacies in the Washington, DC, area. Prices obtained in December 2008. Pricing information was also derived by Consumer Reports Best Buy Drugs from data provided by Symphony Health Solutions. This data represents nationwide averages for October 2008. Symphony Health Solutions is not involved in our analysis or recommendations. The costs of all of these medications can vary significantly, especially online, so we encourage you to shop around to find the best price.

5. These medicines can be taken every day for weeks or months, but also may be taken just a few times a months for occasional constipation. We give the average monthly cost.

6. These medicines are not recommended for long-term use. We give the average price here per bout of constipation.

7. These are specialty medicines for severe constipation. The monthly cost is given but in practice use may be for days or weeks only.

8. Zelnorm is no longer available to most patients. It can only be obtained through a special request to the FDA.

NOTE: The information contained in the Consumer Reports Best Buy Drugs™ reports is for general informational purposes and is not intended to replace consultation with a physician or other health-care professional. Consumers Union is not liable for any loss or injury related to your use of the reports. The reports are intended solely for individual, noncommercial use and may not be used in advertising, promotion, or for any other commercial purpose.


Copyright 2010, Consumers Union of United States, Inc

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