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Sodium phosphate dibasic/sodium phosphate monobasic (By mouth)

Sodium Phosphate, Dibasic (SOE-dee-um FOS-fate, dye-BAY-sik), Sodium Phosphate, Monobasic (SOE-dee-um FOS-fate, mono-BAY-sik)

Helps empty your bowels before surgery or a medical procedure. Also treats constipation.

Brand Name(s):

Leader Saline Laxative, OsmoPrep, Phospha-Lax, Saline Laxative

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 had an allergic reaction to sodium phosphate dibasic or sodium phosphate monobasic. Do not use it if you have acute phosphate nephropathy, stomach or bowel problems (such as bleeding or blocked bowels), irritated colon (toxic colitis or toxic megacolon), or have had stomach surgery (such as gastric bypass or stapling surgery).

How to Use This Medicine:

Liquid, Tablet

  • Follow the instructions on the medicine label if you are using this medicine without a prescription.
  • Follow the schedule given to you by your doctor if you are using this medicine to empty your bowels before surgery or medical tests.
  • Tablets:
    • You will take several tablets at the same time. Your doctor will tell you how many tablets to take.
    • Drink 8 ounces of clear liquids each time you take a group of tablets. Examples of clear liquids are water, flavored water, lemonade (no pulp), ginger ale, or apple juice.
    • Do not drink any purple or red liquids while you use this medicine.
  • Oral liquid: Measure the oral liquid medicine with a marked measuring spoon, oral syringe, or medicine cup. Mix the oral liquid with at least 4 ounces of water before you drink it. After taking the liquid medicine, drink another full glass (8 ounces) of water.
  • Drink as much extra liquid as you can before, during, and after taking this medicine. This will help replace the fluids you are losing with your bowel movements. This will also keep your kidneys working well.
  • 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. The oral liquid can be chilled to improve the taste. Do not freeze the oral liquid.
  • Follow the instructions on the medicine label if you are using this medicine without a prescription. If using the over-the-counter preparation for constipation, do not use more than 1 dose in 24 hours.

Drugs and Foods to Avoid:

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

  • There are many other drugs that can interact with sodium phosphate. Tell your doctor about all other medicines you are taking, especially the following:
    • a diuretic (water pill)
    • a laxative or enema to treat constipation
    • a tricyclic antidepressant (such as amitriptyline, nortriptyline)
    • an NSAID pain and arthritis medicine (such as aspirin, ibuprofen, naproxen)
    • blood pressure medicine including ACE inhibitors or angiotensin receptor blockers

Warnings While Using This Medicine:

  • Tell your doctor if you are pregnant or breastfeeding, or if you have kidney disease, heart failure, heart rhythm problems (such as arrhythmia, prolonged QT interval), inflammatory bowel disease, ulcerative colitis, trouble with swallowing or gastric reflux, a history of seizures, a mineral imbalance (such as high or low calcium, phosphate, potassium, or sodium levels), or if you are on a low-salt diet. Tell your doctor if you had a recent heart attack or heart surgery.
  • This medicine may cause kidney or heart problems.
  • 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
  • Blood in your urine, lower back pain, side pain, or sharp back pain just below your ribs
  • Confusion, weakness, and muscle twitching
  • Decrease in how much or how often you urinate
  • Dizziness or fainting
  • Dry mouth, increased thirst, muscle cramps, nausea or vomiting
  • Fast, pounding, or uneven heartbeat
  • Red or black stools
  • Seizures
  • Severe stomach pain, nausea, vomiting, or 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: 7/4/2018

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites.

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