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Compare Lactulose vs. Miralax

Head-to-head comparisons of medication uses, side effects, warnings, and more.

Key takeaways

Lactulose (Constulose) and polyethylene glycol 3350 (Miralax) are both osmotic laxatives used to treat constipation, but they have some key differences. Lactulose is a prescription medication, while Miralax is available over-the-counter. Lactulose typically takes 1 to 2 days to work, whereas Miralax can take 1 to 3 days. Lactulose can cause side effects like stomach pain and gas, and it might not be suitable for people who are lactose intolerant or on a low-galactose diet. On the other hand, Miralax is less likely to cause these side effects and is considered safer for people with kidney problems. Additionally, Miralax is tasteless and can be mixed with various beverages, making it easier to take. If you need quick relief from constipation, neither medication may be the best option since they can several days to work.

  • Lactulose (Constulose)
    Polyethylene glycol (Miralax)
  • Lactulose (Constulose)
    Polyethylene glycol (Miralax)

  • Summary of Lactulose vs. Miralax

    Summary for Osmotic laxative
    Prescription only

    Lactulose (Constulose) is a liquid osmotic laxative. It's used to help relieve constipation in adults. This medication is taken by mouth, typically once daily. Once you start treatment, it can take up to two days before you have a bowel movement. Some common side effects of lactulose (Constulose) include stomach pain and passing gas. There's a separate version of lactulose used for symptoms of a liver problem called hepatic encephalopathy.

    Summary for Osmotic laxative

    Polyethylene glycol (Miralax) is an over-the-counter (OTC) medication used for occasional constipation. It comes as a powder that you need to mix with a beverage and then drink. Typically, you take a dose of polyethylene glycol (Miralax) once a day, for up to a week. Most people will experience a bowl movement in 1 to 3 days. Some side effects that polyethylene glycol (Miralax) can cause include nausea, bloating, and passing gas.

  • Indications of Lactulose vs. Miralax

    Indications for
    •Constipation
    Indications for
    •Occasional constipation and irregular bowel movements

  • Pros and Cons of Lactulose vs. Miralax

    Pros and Const for Osmotic laxative
    Pros
    •Can be used in people with kidney or liver problems
    •Might be a good option for people with constipation who didn’t see benefits with other laxatives
    •Available as a lower-cost generic medication
    •Side effects are mild and typically go away with time
    Cons
    •Not a good option for people who are lactose intolerant
    •Not appropriate for people on a low-galactose diet
    •Not a first-choice laxative because of the side effects
    •Can take up to 2 days for you to have a bowel movement
    Pros and Const for Osmotic laxative
    Pros
    •Available OTC, so you don't need a prescription from your provider
    •Causes less cramping, bloating, gas, or feelings of "having to go right now" compared to other laxatives
    •A possible option during pregnancy, if provider says it's safe for you to take
    Cons
    •Can take a few days before you have a bowel movement
    •Only for short-term relief of constipation
    •Might cause loose, watery stools

  • Common Side Effects of Lactulose vs. Miralax

    Common Side Effects for
    •Passing gas
    •Stomach cramps
    Common Side Effects for
    •Nausea
    •Passing gas
    •Bloating

  • Warnings of Lactulose vs. Miralax

    Common Side Effects for
    •Loss of fluids
    •Possible risk of high blood sugar
    •Problems during colonoscopy
    Common Side Effects for
    •Complete or partial blockage of intestines

  • Prices with our coupons for Lactulose vs. Miralax

    Learn more about Lactulose
    Learn more about Polyethylene glycol

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