MiraLAX (polyethylene glycol 3350) is a brand-name powder that’s used for constipation. MiraLAX has interactions with some other drugs and certain supplements. Examples include loop diuretics and hydrocodone.

MiraLAX is used to treat constipation in adults and children ages 17 years. It’s available over-the-counter (OTC), but doctors can also write a prescription for it.

MiraLAX may also be used for colonoscopy bowel preparation. Certain interactions only apply when MiraLAX is used for this purpose.

An interaction occurs when one substance causes another substance to have a different effect than expected.

To learn more about MiraLAX’s interactions, keep reading. For additional information about MiraLAX, including details about its uses, see this article.

Before you start treatment with MiraLAX, tell your doctor and pharmacist which prescription, over-the-counter, and other medications you take. By sharing this information with them, you may help prevent possible interactions. (To learn whether MiraLAX interacts with supplements, herbs, or vitamins, see the “MiraLAX and other interactions” section.)

If you have questions about drug interactions that may affect you, ask your doctor or pharmacist. They can advise what drugs should not be taken with MiraLAX.

Here’s a table of drugs that can interact with MiraLAX. Keep in mind that this table doesn’t include all drugs that may interact with MiraLAX. Some of these interactions are described in detail in “Drug interactions in depth.”

Drug class or drug nameDrug examplesInteraction result with MiraLAX
loop diureticsfurosemide (Lasix)
bumetanide (Bumex)
can increase the risk of side effects of MiraLAX or loop diuretics
stimulant laxatives• bisacodyl (Dulcolax)
• docusate sodium (Colace)
can increase the risk of side effects of MiraLAX when used for colonoscopy bowel preparation
atropine/diphenoxylate (Lomitil)can make MiraLAX or atropine/diphenoxylate less effective
dichlorphenamide (Keveyis, Ormalvi)can increase the risk of low blood potassium as a side effect of MiraLAX or dichlorphenamide
hydrocodone (Hysingla ER)can make hydrocodone less effective
lactulose (Generlac)can make it difficult to know whether lactulose is working properly
pimozidecan increase the risk of long QT syndrome as a side effect of pimozide

In some cases, factors or conditions could prevent your doctor or pharmacist from recommending MiraLAX due to the risk of harm. These are known as contraindications. The contraindications of MiraLAX include:

Having had an allergic reaction to MiraLAX or any of its ingredients

If you have had an allergic reaction to MiraLAX or any of its ingredients, your doctor or pharmacist will likely not recommend MiraLAX. Taking the drug could cause another allergic reaction. You can ask them about other treatments that may be better choices for you.

Note: Before you start treatment with MiraLAX, it’s important to tell your doctor or pharmacist if the above applies to you. They can determine whether to recommend MiraLAX.

There aren’t any known interactions between MiraLAX and alcohol. However, your doctor or pharmacist may advise you to avoid or limit alcohol consumption during MiraLAX treatment.

This is because drinking alcohol may worsen constipation. Alcohol may also cause diarrhea, which is a possible side effect of MiraLAX.

If you have questions about drinking alcohol while using MiraLAX, talk with your doctor or pharmacist.

Here’s a closer look at certain drug interactions of MiraLAX.

Lactulose

MiraLAX can interact with lactulose, which is used to treat constipation. Lactulose is also used to treat a complication of severe liver disease called hepatic encephalopathy.

Interaction result:Taking MiraLAX and lactulose can make it difficult to tell whether lactulose is working effectively.

Interaction explained:Both MiraLAX and Lactulose are laxatives that cause bowel movements. However, with lactulose, you’ll need to monitor your bowel movements to find the right dosage of lactulose to take. If MiraLAX is used at the same time as lactulose, it can be hard to know if MiraLAX or lactulose is causing the bowel movement. This makes it difficult for your doctor to know if your lactulose dosage needs to be adjusted, especially when lactulose is used to treat hepatic encephalopathy.

Steps you or your doctor may take:Due to this interaction, doctors typically won’t recommend using MiraLAX and lactulose together. Talk with your doctor if you have additional questions about this interaction.

Hydrocodone

MiraLAX can interact with hydrocodone. Hydrocodone is an opioid prescribed to treat moderate or severe pain.

Interaction result: Taking MiraLAX and hydrocodone can make hydrocodone less effective.

Interaction explained: MiraLAX can affect the absorption of hydrocodone if these medications are used together. MiraLAX can increase how quickly food and medications, including hydrocodone, move through your gastrointestinal (GI) tract. This can decrease the amount of hydrocodone your body absorbs, making hydrocodone less effective.

Steps you or your doctor may take: It’s typically considered safe to use MiraLAX and hydrocodone together. If you need to take MiraLAX and hydrocodone, your doctor can closely monitor how well hydrocodone is working to treat your pain. If needed, they can adjust your hydrocodone dosage.

Your doctor can also tell you how long after taking MiraLAX you can take medications, such as hydrocodone.

Loop diuretics

MiraLAX can interact with loop diuretics. These drugs are prescribed to treat edema (bloating and fluid buildup) caused by certain conditions, such as heart failure.

Interaction result: Taking MiraLAX and a loop diuretic together can increase the risk of electrolyte problems and kidney injury as a side effect of MiraLAX or loop diuretics.

Interaction explained: Both MiraLAX and loop diuretics can cause electrolyte imbalance as a side effect. They can also both cause dehydration, which raises your risk of sudden kidney injury.

Examples of loop diuretic drugs: Here are some loop diuretics that may interact with MiraLAX:

Steps you or your doctor may take: If you need to take MiraLAX and a loop diuretic together, your doctor will likely closely monitor your kidney function and electrolyte levels. They can tell you more about how they’ll do so. It may involve using blood tests.

MiraLAX may have other interactions, such as with supplements, foods, vaccines, or even lab tests. You’ll find details below. Keep in mind that the following information does not include all other possible interactions with MiraLAX.

MiraLAX interactions with supplements

Before you start treatment with MiraLAX, tell your doctor and pharmacist which supplements, herbs, and vitamins you take. By sharing this information with them, you may help prevent possible interactions.

In addition to the interactions below, MiraLAX may interact with castor oil supplements when MiraLAX is used for colonoscopy bowel preparation. Castor oil is used to treat constipation. Taking MiraLAX for colonoscopy bowel preparation and using castor oil products can raise your risk of inflammation or ulcers (sores) in your colon. So, if you take MiraLAX before your colonoscopy, your doctor will likely advise you to avoid using castor oil products until after your colonoscopy.

If you have questions about drug interactions that may affect you, ask your doctor or pharmacist.

MiraLAX interactions with herbs

It’s possible for MiraLAX to interact with an herb called Senna when MiraLAX is used for colonoscopy bowel preparation. Senna is used to treat constipation. Taking MiraLAX for colonoscopy bowel preparation and using Senna can raise your risk of inflammation or ulcers in your colon.

If you need to use MiraLAX for colonoscopy bowel preparation, your doctor will likely recommend you avoid using Senna products until after your colonoscopy.

MiraLAX interactions with vitamins

There are no specific reports of vitamins interacting with MiraLAX. However, that doesn’t mean vitamin interactions won’t occur or be recognized in the future. Because of this, you should talk with your doctor or pharmacist before taking any vitamin product with MiraLAX.

MiraLAX interactions with food

There were no reports of food interactions with MiraLAX. If you’d like to learn more about eating certain foods during treatment with MiraLAX, talk with your doctor or pharmacist.

MiraLAX interactions with vaccines

There aren’t any known interactions between MiraLAX and vaccines. Talk with your doctor or pharmacist to see whether you’re due for any vaccines.

MiraLAX interactions with lab tests

MiraLAX isn’t known to interact with any lab tests. If you have concerns about this medication interacting with lab tests, talk with your doctor.

MIRALAX INTERACTION WITH CANNABIS OR CBD

Cannabis (often called marijuana) and cannabis products, such as cannabidiol (CBD), have not been specifically reported to interact with MiraLAX. However, as with any drug or supplement, talk with your doctor or pharmacist before using cannabis in combination with MiraLAX. The impact of cannabis may affect how well you stick to your MiraLAX treatment plan.

Note: Cannabis is illegal at a federal level but is legal in many states to varying degrees.

Certain medical conditions and other factors may increase the risk of interactions with MiraLAX. Before you take this drug, be sure to talk with your doctor or pharmacist about your health history. MiraLAX may not be the right treatment option if you have certain medical conditions or other factors affecting your health.

Health conditions or factors that might interact with MiraLAX include:

  • Irritable bowel syndrome: MiraLAX may worsen certain symptoms of irritable bowel syndrome (IBS). Your doctor or pharmacist can provide more information on safely using laxatives if you have IBS.
  • Kidney conditions, such as chronic kidney disease: Talk with your doctor or pharmacist before using MiraLAX if you have a kidney condition, such as chronic kidney disease. MiraLAX can cause electrolyte imbalances, and people with a kidney condition may have a higher risk of this side effect.
  • Allergic reaction: If you’ve had an allergic reaction to MiraLAX or any of its ingredients, your doctor or pharmacist will likely not recommend MiraLAX. Taking the drug could cause another allergic reaction. You can ask them about other treatments that may be better choices for you.
  • Breastfeeding: It’s generally considered safe to use MiraLAX while breastfeeding. But it’s best to talk with your doctor or pharmacist before doing so. To learn more about MiraLAX and breastfeeding, see this article.
  • Pregnancy: MiraLAX is considered safe for short-term use during pregnancy. If you’re pregnant or planning to become pregnant, tell your doctor or pharmacist before starting MiraLAX. They can advise on the right treatment plan for you. To learn more about MiraLAX and pregnancy, see this article.

You can take certain steps to help prevent interactions with MiraLAX. Your doctor and pharmacist are key resources, so reach out to them before starting treatment. For example, you should plan to do the following:

  • Let them know if you drink alcohol or use cannabis.
  • Tell them about any other medications you take, as well as any supplements, herbs, and vitamins.
  • Create a medication list, which your doctor and pharmacist can help you fill out.

It’s also important to read the MiraLAX label and other paperwork that may come with the drug. The label may have colored stickers that mention an interaction. And the paperwork, sometimes called the medication guide or patient package insert, may contain details about interactions. If you need help reading or understanding this information, ask your doctor or pharmacist.

You can also help prevent interactions with MiraLAX by taking it exactly as your doctor or pharmacist recommends.

Disclaimer: Medical News Today 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.