Brand Name(s):

  • OsmoPrep®
  • Visicol®


Sodium phosphate has caused serious kidney damage in some people. In some cases, this damage was permanent, and some people whose kidneys were damaged had to be treated with dialysis (treatment to remove waste from the blood when the kidneys are not working well). Some people developed kidney damage within a few days after their treatment, and others developed kidney damage up to several months after their treatment. Tell your doctor if you are constipated, you have severe stomach pain or bloating, you think you may be dehydrated (have lost a lot of fluid from your body), or you have or develop symptoms of dehydration such as vomiting, dizziness, decreased urination, and headache. Also tell your doctor if you have ever had a biopsy (removal of a piece of tissue for examination in a laboratory) that showed that you have kidney problems caused by too much phosphate; or if you have or have ever had a low level of calcium, sodium, magnesium, or potassium in your blood; a high level of sodium or phosphate in your blood; colitis (inflammation of the large intestine) or other conditions that irritate your intestine; a blockage or tear in your intestine; slow moving bowels; or heart or kidney disease. Also tell your doctor and pharmacist if you are taking angiotensin converting enzyme inhibitors (ACEIs) such as benazepril (Lotensin, in Lotrel), captopril (Capoten, in Capozide), enalapril (Vasotec), fosinopril (Monopril), lisinopril (Prinivil, Zestril, in Prinzide and Zestoretic), moexipril (Univasc, in Uniretic), perindopril (Aceon), quinapril (Accupril, in Accuretic and Quinaretic), ramipril (Altace), or trandolapril (Mavik, in Tarka); aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (Advil, Motrin, others) and naproxen (Aleve, Naprosyn, others); angiotensin receptor blockers (ARBs) such as candesartan (Atacand), eprosartan (Teveten), irbesartan (Avapro, in Avalide), losartan (Cozaar, in Hyzaar), olmesartan (Benicar), telmisartan (Micardis), or valsartan (Diovan); or diuretics (water pills). The risk that you may develop kidney damage is higher if you have any of these conditions, are taking any of these medications, or are older than 55 years old. However, you may develop kidney damage even if you do not have any of these conditions, are not taking any of these medications, and are younger than 55 years old. If you experience any of the following symptoms, call your doctor immediately: weakness, drowsiness, decreased urination, or swelling of the ankles, feet, or legs.

Follow the directions on your prescription label carefully and ask your doctor or pharmacist to explain any part you do not understand. Take sodium phosphate exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor. Taking more sodium phosphate than prescribed by your doctor increases the risk that you will develop kidney damage.

Keep all appointments with your doctor and the laboratory. Your doctor may order certain tests to check your body's response to sodium phosphate.

Your doctor or pharmacist will give you the manufacturer's patient information sheet (Medication Guide) when you begin treatment with sodium phosphate. Read the information carefully and ask your doctor or pharmacist if you have any questions. You can also visit the Food and Drug Administration (FDA) website ( Web Site) or the manufacturer's website to obtain the Medication Guide.

Talk to your doctor about the risks of taking sodium phosphate.

WHY is this medicine prescribed?

Sodium phosphate is used to completely empty the colon (large intestine, bowel) before a colonoscopy (examination of the inside of the colon to check for colon cancer and other abnormalities) so that the doctor will have a clear view of the walls of the colon. Sodium phosphate is in a class of medications called saline laxatives. It works by causing diarrhea so that all the stool can be emptied from the colon.

HOW should this medicine be used?

Sodium phosphate comes as a tablet to take by mouth. It is usually taken as one dose the night before a colonoscopy is scheduled and one dose about 12 hours later on the morning of the procedure. For each dose, your doctor will tell you to take a certain number of tablets with 8 ounces of clear liquid, wait 15 minutes, and then take more tablets with 8 ounces of clear liquid. You will repeat this several more times until you have taken all the tablets that your doctor prescribed for that dose.

It is very important that you drink the full amount of clear liquid with each dose of sodium phosphate, and that you drink plenty of clear liquid at other times before, during, and after your treatment with sodium phosphate. Clear liquids are liquids that can be seen through such as water, flavored water, lemonade without pulp, apple juice, and ginger ale. Do not drink any liquids that are colored purple or red. Tell your doctor if you have trouble drinking clear liquids.

You will have many bowel movements while you are taking sodium phosphate and for some time after you finish taking the medication. Be sure to stay close to a toilet during this time.

There may be 2 small paper packets inside your bottle of sodium phosphate tablets. These are placed in the bottle to keep the medication from becoming too moist and are not to be swallowed.

Are there OTHER USES for this medicine?

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

What SPECIAL PRECAUTIONS should I follow?

Before taking sodium phosphate,

  • tell your doctor and pharmacist if you are allergic to sodium phosphate or any other medications.
  • tell your doctor if you have already taken sodium phosphate within the past 7 days. You should not take sodium phosphate more than once in 7 days.
  • tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention the medications listed in the IMPORTANT WARNING section and any of the following: amiodarone (Cordarone, Pacerone), ,antidepressants, cisapride (Propulsid), disopyramide (Norpace), dofetilide (Tikosyn), erythromycin (E.E.S., E-Mycin, Erythrocin), medications for anxiety or seizures,. moxifloxacin (Avelox), pimozide (Orap), procainamide (Procanbid, Pronestyl), quinidine (Quinidex),sotalol (Betapace, Betapace AF), sparfloxacin (Zagam), or thioridazine (Mellaril).Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
  • do not take any other laxatives or enemas, especially other products that contain sodium phosphate, while you are taking this medication.
  • if you are taking any other medications, talk to your doctor about when you should take them during your treatment with sodium phosphate. Medications that you take shortly before or after you take sodium phosphate may be washed out of your body before you can benefit from them. If this happens, you may see the undigested tablets in your stool.
  • tell your doctor if you follow a low salt diet, if you had been drinking large amounts of alcohol or taking medications for anxiety or seizures and are now gradually decreasing your use of these substances, and if you have had stomach or heart surgery. Also tell your doctor if you have or have ever had a prolonged QT interval (a rare heart problem that may cause irregular heartbeat, fainting, or sudden death), an irregular heartbeat, a heart attack, chest pain, seizures, build-up of fluid around your organs, irritable bowel disease (IBD; a group of conditions in which all or part of the lining of the intestine is swollen, irritated, or has sores) bulimia (an eating disorder), difficulty swallowing, or narrowing of your esophagus (tube that brings food from the mouth to the stomach).
  • tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding.

What SPECIAL DIETARY instructions should I follow?

Your doctor will tell you what you may eat and drink before, during, and after your treatment with sodium phosphate. Follow these directions carefully.

What should I do IF I FORGET to take a dose?

Call your doctor if you forget or are unable to take sodium phosphate exactly as directed.

What SIDE EFFECTS can this medicine cause?

Sodium phosphate may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

  • nausea
  • stomach pain
  • bloating

Some side effects can be serious. If you experience any of these symptoms or those listed in the IMPORTANT WARNING section, call your doctor immediately:

  • irregular heartbeat
  • fainting
  • seizures
  • rash
  • hives
  • itching
  • swelling of the eyes, face, lips, tongue, mouth or throat
  • throat tightness
  • difficulty breathing or swallowing

Sodium phosphate may cause other side effects. Call your doctor if you have any unusual problems while you are taking this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online [at Web Site] or by phone [1-800-332-1088].

What should I know about STORAGE and DISPOSAL of this medication?

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.

What should I do in case of OVERDOSE?

In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.

Symptoms of overdose may include:

  • vomiting
  • dizziness
  • headache
  • decreased urination
  • seizures
  • irregular heartbeat

What OTHER INFORMATION should I know?

You may see undigested or partially digested sodium phosphate tablets in your stool. This is because the medication moves quickly through your digestive system.

Do not let anyone else take your medication. Your prescription is probably not refillable, since you will not need more sodium phosphate after your colonoscopy.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.

AHFS® Consumer Medication Information. © Copyright, The American Society of Health-System Pharmacists, Inc., 7272 Wisconsin Avenue, Bethesda, Maryland. All Rights Reserved. Duplication for commercial use must be authorized by ASHP.

Selected Revisions: June 1, 2009.