Amitiza (lubiprostone) is a prescription drug that’s used to treat certain types of constipation. This drug can interact with other medications. For example, Amitiza can interact with methadone and certain diuretics (water pills).
Amitiza is used in adults to treat:
- chronic idiopathic constipation (CIC)
- opioid-induced constipation (OIC) in people taking opioids for long-term pain that’s unrelated to cancer
- irritable bowel syndrome with constipation (IBS-C) in adult females*
An interaction can occur because one substance causes another substance to have a different effect than expected. Interactions can also occur if you have certain health conditions.
Keep reading to learn about Amitiza’s possible interactions. And for more information about Amitiza, including details about its uses, see this article.
* In this article, we use the term “female” to refer to someone’s sex assigned at birth. For information about the difference between sex and gender, see this article.
Before you start taking Amitiza, tell your doctor and pharmacist about any prescription, over-the-counter, or other drugs you take. Sharing this information with them may help prevent possible interactions. (To learn whether Amitiza interacts with herbs or vitamins and supplements, see the “Are there other interactions with Amitiza?” section.)
If you have questions about drug interactions that may affect you, talk with your doctor or pharmacist.
The table below lists drugs that may interact with Amitiza. Keep in mind that this table does not include all drugs that may interact with Amitiza. For more information about some of these interactions, see the “Drug interactions explained” section.
| Drug group or drug name | Drug examples | What can happen |
| methadone (Methadose) | — | can make Amitiza less effective |
| loop diuretics | • furosemide (Lasix) • bumetanide (Bumex) • torsemide (Demadex) | can increase the risk of side effects from Amitiza and the diuretic |
| anticholinergic drugs | • diphenhydramine (Benadryl) • darifenacin • scopolamine • tolterodine (Detrol) | can make Amitiza less effective |
| anti-diarrheal medications | • alosetron (Lotronex) • loperamide (Imodium) • diphenoxylate/atropine (Lomotil) | can make Amitiza less effective |
Certain health conditions or other factors could raise your risk of harm if you take Amitiza. In such cases, your doctor may not prescribe Amitiza for you. These are known as contraindications. The list below includes contraindications of Amitiza.
If you have a blockage in your bowel: If you have a bowel blockage, your doctor likely won’t prescribe Amitiza. An obstruction in your bowel can block food from moving down your digestive tract. This can cause pain, nausea, and vomiting. Tell your doctor if you have any symptoms of a bowel obstruction. They can do a physical exam to determine if it’s safe for you take Amitiza.
If you’ve had an allergic reaction: If you’ve had an allergic reaction to Amitiza or any of its ingredients, your doctor likely won’t prescribe Amitiza for you. This is because taking the drug could cause another allergic reaction. You can ask your doctor about other treatments that may be better options for you.
Before you start taking Amitiza, talk with your doctor if any of the factors above apply to you. Your doctor can determine whether Amitiza is safe for you to take.
Amitiza is not known to interact with alcohol. But, Amitiza and alcohol can cause some similar side effects, such as nausea, vomiting, and headache. So you may be more likely to experience these side effects if you drink alcohol during your Amitiza treatment.
If you have questions about consuming alcohol taking Amitiza, talk with your doctor or pharmacist.
Learn more about certain drug interactions that can occur with Amitiza.
Interaction with methadone
Amitiza can interact with methadone, which is an opioid drug used to treat moderate to severe pain and opioid addiction.
What could happen
Taking Amitiza with methadone can make Amitiza less effective at treating your constipation.
What you can do
If you take Amitiza and methadone together, tell your doctor if your constipation isn’t getting better or is getting worse. They can help determine if it’s safe for you to continue taking these drugs together or if there are safer medications for you.
If you have questions about taking Amitiza with methadone, talk with your doctor or pharmacist.
Interaction with loop diuretics
A loop diuretic is a type of water pill that’s used to treat high blood pressure and heart failure.
Examples of loop diuretic medications:
- furosemide (Lasix)
- bumetanide (Bumex)
- torsemide (Demadex)
What could happen
Taking Amitiza with a loop diuretic can raise your risk of hypokalemia (low blood potassium levels).
What you can do
If you take Amitiza with a loop diuretic, tell your doctor right away if you have symptoms of hypokalemia. These may include weakness, fatigue, muscle cramping, or heart palpitations. Your doctor may order a blood test to check your potassium level. If the level is low, your doctor may prescribe a potassium supplement.
If you have questions about taking Amitiza with a loop diuretic, talk with your doctor or pharmacist.
Interaction with diarrhea medications
Anti-diarrheal drugs are used to treat diarrhea. There are both prescription and over-the-counter (OTC) diarrhea drugs available.
Examples of anti-diarrheal medications:
- alosetron (Lotronex)
- loperamide (Imodium)
- diphenoxylate/atropine (Lomotil)
What could happen
Taking Amitiza with a diarrhea medication can make Amitiza less effective at managing your constipation and could also make your constipation symptoms worse.
What you can do
Before taking any diarrhea drugs, talk with your doctor. They can help determine if it’s safe to take with Amitiza.
If you take Amitiza and an anti-diarrheal together, tell your doctor right away if your constipation isn’t improving or is getting worse. They can discuss alternative medications that may work better for you.
Amitiza may have other interactions. They could occur with supplements, foods, vaccines, or even lab tests. See below for details. Note that this information does not include all other possible interactions with Amitiza.
Does Amitiza interact with supplements?
Before you start taking Amitiza, talk with your doctor and pharmacist about any herbs or vitamins and supplements you take. Sharing this information with them may help you avoid possible interactions.
If you have questions about interactions that may affect you, talk with your doctor or pharmacist.
Amitiza interactions with herbs
There are currently no reports of Amitiza interacting with herbs. But this doesn’t mean that interactions with herbs won’t be recognized in the future.
For this reason, it’s still important to check with your doctor or pharmacist before taking any of these products while taking Amitiza.
Amitiza interactions with vitamins
There are currently no reports of Amitiza interacting with vitamins. But this doesn’t mean that vitamin interactions won’t be recognized in the future.
For this reason, it’s still important to check with your doctor or pharmacist before taking any of these products while taking Amitiza.
Does Amitiza interact with food?
There are currently no reports of Amitiza interacting with food. If you have questions about eating certain foods during your treatment with Amitiza, talk with your doctor.
Does Amitiza interact with vaccines?
There are currently no reports of Amitiza interacting with vaccines. If you have questions about getting certain vaccines during your Amitiza treatment, talk with your doctor.
Does Amitiza interact with lab tests?
There are currently no reports of Amitiza interacting with lab tests. If you have questions about having certain lab tests during your treatment with Amitiza, talk with the healthcare professional ordering the test.
Does Amitiza interact with cannabis or CBD?There are currently no reports of Amitiza interacting with cannabis (commonly called marijuana) or cannabis products such as cannabidiol (CBD). But as with any drug or supplement, talk with your doctor before using cannabis with Amitiza.
Note: Cannabis is illegal at a federal level but is legal in many states to varying degrees.
Certain medical conditions or other health factors may raise the risk of interactions with Amitiza. Before taking Amitiza, talk with your doctor about your health history. They’ll determine whether Amitiza is right for you.
Health conditions or other factors that might interact with Amitiza include:
Severe diarrhea. Amitiza can cause diarrhea as a side effect. If you already have severe diarrhea, taking Amitiza can worsen your condition. Due to this risk, your doctor likely won’t prescribe Amitiza if you have severe diarrhea.
Bowel obstruction> If you have a blockage in your bowel, food may not be able to pass through your digestive tract. This can prevent the drug from working properly. Because of this, your doctor likely won’t prescribe Amitiza if you have a bowel obstruction.
High blood pressure. If you have a history of high blood pressure and are using medications that lower your blood pressure, you may be at increased risk of experiencing hypotension, low blood pressure, and syncope, fainting. Your doctor will discuss the benefits and risks with you to determine what is the best treatment for you.
Pregnancy. It’s not known whether Amitiza is safe to take during pregnancy. If you’re pregnant or planning a pregnancy, talk with your doctor before taking Amitiza.
Breastfeeding. It’s not known whether it’s safe to take Amitiza while breastfeeding. It’s not known whether the drug passes into breast milk or what side effects it may cause in a child who’s breastfed. If you’re breastfeeding or planning to breastfeed, talk with your doctor about your options.
Allergic reaction. If you’ve had an allergic reaction to Amitiza or any of its ingredients, your doctor will likely not prescribe Amitiza. This is because taking the drug could cause another allergic reaction. You can ask your doctor about other treatments that may be better choices for you.
Taking certain steps can help you avoid interactions with Amitiza. Before starting treatment, talk with your doctor and pharmacist. Things to discuss with them include:
- whether you drink alcohol or use cannabis
- other medications you take, as well as any vitamins, supplements, and herbs (they can also help you fill out a
medication list ) - what to do if you start taking a new drug during your Amitiza treatment
It’s also important to understand Amitiza’s
If you have trouble reading or understanding this information, your doctor or pharmacist can help.
Taking Amitiza exactly as prescribed can also help prevent interactions.
Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.