Linzess vs. Amitiza for Constipation: The 7 Key Differences You Need to Know

Constipation is a common gut-related health condition that causes hard or difficult-to-pass stools. While occasional constipation is normal, chronic constipation can take a toll. Some people may experience chronic constipation due to irritable bowel syndrome (IBS) or chronic idiopathic constipation (CIC).

Fortunately, you have several treatment options available to help regulate your bowel movements and ease discomfort. For people with chronic constipation or IBS, over-the-counter (OTC) treatments may not be enough. Two prescription medications that may help are Linzess (linaclotide) and Amitiza (lubiprostone). Both are preferred medications when OTC medications don't relieve constipation symptoms. But they have some key differences.

Here, we'll compare Linzess versus Amitiza and go over seven key points to help you decide which option may be best for you.

1. Linzess and Amitiza treat constipation differently

Linzess and Amitiza have unique mechanisms of action. Meaning, they relieve constipation in different ways.

Linzess is a guanylate cyclase-C (GC-C) agonist. It works by turning on GC-C receptors (chemical binding sites) in the intestines. This causes your intestines to release more fluid to soften your stool and speeds up bowel activity. What’s more, Linzess may help relieve abdominal pain by activating GC-C receptors.

Amitiza is a chloride channel activator. It raises the amount of fluid in the intestines. And just like a laxative, this softens your stool, helping it to pass more easily.

2. Linzess and Amitiza both treat constipation, but they have slightly different uses

Linzess and Amitiza are FDA approved to treat different types of constipation. These include IBS with constipation (IBS-C) and CIC — a long-term condition where constipation occurs without a clear cause.

Here’s how Linzess’ and Amitiza’s specific uses compare.

3. Amitiza has some gender restrictions with IBS-C

Amitiza is only FDA approved for adult women with IBS-C. That means men with IBS-C can’t take Amitiza to treat their IBS.

EXPERT PICKS: WHAT TO READ NEXT

• Staying ahead of constipation: Constipation can be triggered by different factors. In addition to medication, here are some lifestyle changes you can make to prevent constipation.

• The right treatment for IBS: There are several medications available to treat IBS. Find out which medication may be right for you based on which type of IBS you have.

• Linzess side effects: Use our guide to read up on common Linzess side effects and how to manage them.

Previous studies showed that Amitiza was more effective at treating IBS-C in women compared to men. It’s important to note that these studies included a small number of male participants. So, additional research is needed to support Amitiza’s potential benefits in men with IBS-C. Amitiza, however, doesn’t have any gender restrictions when used for CIC or OIC.

In contrast, Linzess does not have any gender restrictions. It’s approved for men and women no matter what it’s treating.

4. Linzess and Amitiza have different dosage schedules

Linzess and Amitiza are available in different doses. Linzess comes in 72 mcg, 145 mcg, and 290 mcg capsules. Amitiza comes in 8 mcg and 24 mcg capsules. Moreover, you’ll usually take Linzess once a day, while you’ll typically take Amitiza twice a day. The recommended dosage depends on why you’re taking it.

Here are typical Linzess dosages based on use:

• IBS-C in adults: Take 290 mcg by mouth once daily

• CIC in adults: Take 145 mcg by mouth once daily

• FC in children ages 6 to 17 years old: Take 72 mcg by mouth once daily

These are typical Amitiza dosages based on use:

• IBS-C in adult women: Take 8 mcg by mouth twice daily

• CIC in adults: Take 24 mcg by mouth twice daily

• OIC in adults: Take 24 mcg by mouth twice daily

5. You should take Amitiza with food

Linzess and Amitiza are both oral medications. But they each have particular ways in which they should be taken. These tips help maximize their effectiveness and lower the risk of side effects.

You should take Linzess on an empty stomach, at least 30 minutes before a meal. Linzess is more likely to cause diarrhea when you take it with food. But if you have difficulty swallowing capsules, you can open Linzess and sprinkle it onto applesauce or dissolve it in water.

On the other hand, you should always take Amitiza with food and water. It’ll help prevent nausea.

6. Amitiza tends to start working faster than Linzess

Amitiza starts working faster than Linzess to relieve constipation. Studies show that Amitiza can work as quickly as 4 hours after the first dose, and most people report bowel movements within 48 hours (2 days).

Linzess typically takes longer. Some people report having a bowel movement within 24 hours, but it can take up to a week for Linzess to provide relief from constipation.

If you’re looking for quicker relief, Amitiza may be the better option.

7. Both medications have different side effect profiles

Linzess and Amitiza share several common side effects. But they also have their own unique side effects. This is largely due to their different mechanisms of action, or the differences in how they work.

Linzess’s common side effects include: 

• Diarrhea

• Stomach pain

• Gas

• Bloating

• Headache

By comparison, Amitiza’s common side effects include:

• Nausea

• Diarrhea

• Headache

• Stomach pain

• Gas

• Bloating

Both medications can cause rare but serious side effects too. One that they both have in common is severe diarrhea. Linzess may also cause bloody stools or infections in the sinuses and upper respiratory tract. Amitiza, on the other hand, may cause low blood pressure or shortness of breath.

Linzess also carries a boxed warning — the FDA’s strongest medication warning — for the risk of severe dehydration in children younger than 2 years old. Children younger than 2 years old should not take Linzess as a result. Amitiza does not have a boxed warning. 

If you experience any troublesome side effects from Linzess or Amitiza, talk to your healthcare professional as soon as possible.

How to save on Linzess and Amitiza

If you’re looking to save on Linzess and Amitiza, you have options. Both are available as brand-name medications. But you can also find Amitiza as a lower-cost generic. GoodRx can help you navigate ways to save on your prescription.

• Save with GoodRx: GoodRx can help you save on the average retail price of the generic version of Amitiza. Generic lubiprostone’s price at certain pharmacies is as low as $45.00 with a free GoodRx discount.

• Save with a copay savings card: If you have commercial insurance and meet eligibility requirements, Linzess’ price is as little as $30 using a savings card from the manufacturer.

• Save with patient assistance programs: If you’re uninsured or underinsured, you may be eligible for Linzess’ patient assistance program, which offers the medication free of charge.

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Written by:

Sheila Marie, PharmD

Sheila Marie, PharmD, is a licensed pharmacist in Virginia, New York, and the District of Columbia. She has worked in the pharmacy industry for 12 years and currently works as a community pharmacist.

Edited by:

Joshua Murdock, PharmD, BCBBS

Joshua Murdock, PharmD, BCBBS, is a licensed pharmacist in Arizona, Colorado, and Rhode Island. He has worked in the pharmacy industry for more than 10 years and currently serves as a pharmacy editor for GoodRx.

Reviewed by:

Bailey E. Eason, PharmD, MS, BCPS

Bailey Eason, PharmD, MS, BCPS, is the program director of drug diversion at Northwestern Medicine. Eason has experience as an operating room pharmacy manager and a pharmacy manager of clinical operations.

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