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)

This medicine is used to empty your bowel before surgery or other medical procedures. Also treats constipation.

Brand Name(s)

OsmoPrep, Good Neighbor Pharmacy Phosphate Laxative, Rite Aid Laxative Oral Saline, Leader Oral Saline Laxative, Leader Preparation Cleansing Kit, Rite Aid Oral Saline Laxative, Oral Saline Laxative, Rite Aid Phospha-Lax, Visicol

There may be other brand names for this medicine.

When This Medicine Should Not Be Used

Do not use this medicine if you have had an allergic reaction to sodium phosphate dibasic or sodium phosphate monobasic. Do not use this medicine 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 schedule given to you by your doctor if you are using this medicine to empty your bowel 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.
  • 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. Read and follow these instructions carefully. Ask your doctor or pharmacist if you have any questions. Ask your pharmacist for the Medication Guide if you do not have one.

How to Store and Dispose of This Medicine

  • 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.
  • Ask your pharmacist, doctor, or health caregiver about the best way to dispose of any outdated medicine or medicine no longer needed.
  • Keep all medicine away from children and never share your medicine with anyone.

Drugs and Foods to Avoid

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

  • Make sure your doctor knows if you are using other medicines that contain sodium phosphate (such as oral saline laxatives, Phospho-Soda®), a diuretic (water pill, such as hydrochlorothiazide, furosemide, Lasix®), certain blood pressure medicines (such as benazepril, enalapril, lisinopril, Avalide®, Avapro®, Benicar®, Cozaar®, Diovan®, Lotrel®, Micardis®, Vasotec®, Zestoretic®, Zestril®), medicines to treat depression (such as amitriptyline, nortriptyline, Elavil®), or an NSAID pain and arthritis medicine (such as aspirin, diclofenac, ibuprofen, naproxen, Advil®, Aleve®, Celebrex®, Motrin®).
  • Make sure your doctor knows if you are also using arsenic trioxide (Trisenox®), cisapride (Propulsid®), dofetilide (Tikosyn®), certain antibiotics (such as erythromycin, levofloxacin, moxifloxacin, sparfloxacin, Avelox®, Levaquin®, Zagam®), or medicine to treat mental illness (such as haloperidol, mesoridazine, pimozide, prochlorperazine, quetiapine, thioridazine, ziprasidone, Compazine®, Geodon®, Haldol®, Mellaril®, Orap®, Serentil®, Seroquel®). Tell your doctor if you have recently stopped drinking alcohol, or if you are taking benzodiazepines (such as alprazolam, clonazepam, diazepam, lorazepam, Xanax®).

Warnings While Using This Medicine

  • Make sure your doctor knows if you are pregnant or breastfeeding, or if you have kidney disease, severe chest pain, congestive heart failure, heart disease, heart rhythm problems (such as arrhythmia, prolonged QT interval), a history of seizures, a mineral imbalance (such as high or low calcium, phosphate, potassium, or sodium in your blood), or if you are on a low-salt diet. Tell your doctor if you have inflammatory bowel disease (IBD), ulcerative colitis, or trouble with swallowing or gastric reflex. Tell your doctor if you also had a recent heart attack or heart surgery.
  • This medicine may cause serious kidney problems. These are more likely to occur if you are older than 65, dehydrated, or you are taking medicines that could be hard on your kidneys.

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 the urine, lower back pain, side pain, or sharp back pain just below the ribs
  • Confusion, trouble breathing
  • Decrease in how much or how often you urinate
  • Dizziness or fainting
  • Dry mouth, increased thirst, muscle cramps
  • Fast, pounding, or uneven heartbeat
  • Numbness or tingling in your mouth, fingertips, or feet
  • Red or black stools
  • Seizures
  • Severe stomach pain, nausea, vomiting, bloating
  • Swelling in your hands, ankles, lower legs, or feet

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

Version Info

  • Last Reviewed on 06/12/2013

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission ( URAC's accreditation program is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial policy, editorial process and privacy policy. A.D.A.M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health on the Net Foundation (

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. © 1997- 2013 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.