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Sodium sulfate, potassium sulfate, and magnesium sulfate (By mouth)

Magnesium Sulfate (mag-NEE-zee-um SUL-fate), Potassium Sulfate (poe-TAS-ee-um SUL-fate), Sodium Sulfate (SOE-dee-um SUL-fate)

Helps empty your bowels before a colonoscopy.

Brand Name(s):

There may be other brand names for this medicine.

When This Medicine Should Not Be Used:

This medicine is not right for everyone. Do not use it if you have an allergic reaction to sodium sulfate, potassium sulfate, and magnesium sulfate.

How to Use This Medicine:

Powder for Solution

  • Your doctor will tell you how much medicine to use. Do not use more than directed.
  • You may drink water or other clear liquids up until 2 hours before the time of the test, if your doctor says it is okay.
  • Drink extra fluids before, during, and after you use this medicine to help replace the fluids that will be lost during your bowel movement. Do not drink anything red or purple.
  • To use:
    • The ColPrep Kit® contains 2 bottles of ColPrep®, taken as a 2-day regimen (Split-dose method).
    • The powder must be mixed with water before it is used. Open 1 bottle of ColPrep Kit® and add water up to the neck of the bottle.
    • Replace cap and shake well and mix thoroughly.
    • Pour the mixed solution into the mixing container provided.
    • Fill the mixing container with water up to the red 16 ounce fill line.
    • Drink all of the liquid in the mixing container.
    • Drink 2 more mixing containers filled up to the 16 ounce fill line with water over the next hour (32 ounces of additional water).
    • Then, on the morning before the colonoscopy, repeat the same steps and complete all ColPrep Kit® solution and required amount of water at least 2 hours before the test.
  • This medicine should come with a Medication Guide. Ask your pharmacist for a copy if you do not have one.
  • Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light.

Drugs and Foods to Avoid:

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

  • Do not take any medicine by mouth within 1 hour before you start using ColPrep Kit®.
  • Some medicine can affect how this medicine works. Tell your doctor if you are using any of the following:
    • Blood pressure medicine
    • Diuretic (water pill)
    • Medicine to treat depression
    • NSAID pain or arthritis medicine (including aspirin, celecoxib, diclofenac, ibuprofen, naproxen)

Warnings While Using This Medicine:

  • Tell your doctor if you are pregnant or breastfeeding, or if you have kidney problems, heart disease (including heart failure, recent heart attack), trouble swallowing, stomach or digestion problems, or a history of seizures or heart rhythm problems (such as arrhythmia, prolonged QT).
  • This medicine may cause the following problems:
    • Dehydration
    • Heart rhythm problems
    • Seizures
    • Stomach or bowel problems, including ulcers, ischemic colitis
  • Keep all medicine out of the reach of children. Never share your medicine with anyone.

Possible Side Effects While Using This Medicine:

Call your doctor right away if you notice any of these side effects:

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
  • Confusion, weakness, and muscle twitching
  • Decrease in how much or how often you urinate
  • Dry mouth, increased thirst, vomiting
  • Fast, slow, or uneven heartbeat
  • Seizures
  • Severe stomach pain or bloating, bloody or black stools

If you notice these less serious side effects, talk with your doctor:

  • Mild nausea, bloating

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088

Last Updated: 2/4/2020

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