Name: Visicol

Why is this medication prescribed?

Sodium phosphate is used in adults 18 years of age or older to 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 the stool can be emptied from the colon.

What special precautions should I follow?

Before taking sodium phosphate,

  • tell your doctor and pharmacist if you are allergic to sodium phosphate, other medications, or any of the ingredients in the tablets. Check the prescription label or ask your pharmacist for a list of the ingredients.
  • tell your doctor if you have already taken sodium phosphate or used an enema containing 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, disopyramide (Norpace), dofetilide (Tikosyn), erythromycin (E.E.S., Erythrocin), medications for anxiety or seizures, moxifloxacin (Avelox), pimozide (Orap), quinidine (Quinidex, in Nuedexta), sotalol (Betapace, Betapace AF, Sorine) or thioridazine. 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 use any enemas while you are taking this medication.
  • if you are taking any other medications by mouth, talk to your doctor about when you should take them during your treatment with sodium phosphate.Medications that you take 1 hour before you take sodium phosphate may not be absorbed properly.
  • 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 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, inflammatory 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 or swallowing.
  • tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding.

What happens if I miss a dose?

Call your doctor for instructions if you miss a dose or do not finish all doses required before your colonoscopy.

Do not use more than the recommended dose of this medicine in any 24-hour period.

What other drugs will affect oral Visicol (sodium biphosphate and sodium phosphate)?

Ask a doctor or pharmacist if it is safe for you to use this medicine if you are also using any of the following drugs:

  • a diuretic or "water pill";

  • NSAIDs (nonsteroidal anti-inflammatory drugs)--aspirin, ibuprofen (Advil, Motrin), naproxen (Aleve), celecoxib, diclofenac, indomethacin, meloxicam, and others; or

  • an antibiotic--azithromycin, clarithromycin, erythromycin, moxifloxacin, pentamidine; an antidepressant--citalopram, escitalopram; anti-malaria medicine--chloroquine, halofantrine; cancer medicine--arsenic trioxide, vandetanib; heart rhythm medicine--amiodarone, disopyramide, dofetilide, flecainide, ibutilide, procainamide, quinidine, sotalol; medicine to treat a psychiatric disorder--chlorpromazine, haloperidol, lithium, pimozide, ziprasidone, others.

This list is not complete. Other drugs may interact with sodium biphosphate and sodium phosphate, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide.

Precautions While Using Visicol

Your health care professional should check your progress at regular visits to make sure that this medicine does not cause unwanted effects.

Do not take iron supplements within 1 to 2 hours of taking this medicine. To do so may keep the iron from working properly.

For patients taking potassium phosphate-containing medicines:

  • Check with your health care professional before starting any strenuous physical exercise, especially if you are out of condition and are taking other medication. Exercise and certain medicines may increase the amount of potassium in the blood.

For patients on a potassium-restricted diet:

  • This medicine may contain a large amount of potassium. If you have any questions about this, check with your health care professional.
  • Do not use salt substitutes and low-salt milk unless told to do so by your health care professional. They may contain potassium.

For patients on a sodium-restricted diet:

  • This medicine may contain a large amount of sodium. If you have any questions about this, check with your health care professional.

If OVERDOSE is suspected

If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

Consumer Information Use and Disclaimer

  • If your symptoms or health problems do not get better or if they become worse, call your doctor.
  • Do not share your drugs with others and do not take anyone else's drugs.
  • Keep a list of all your drugs (prescription, natural products, vitamins, OTC) with you. Give this list to your doctor.
  • Talk with the doctor before starting any new drug, including prescription or OTC, natural products, or vitamins.
  • This medicine comes with an extra patient fact sheet called a Medication Guide. Read it with care. Read it again each time this medicine is refilled. If you have any questions about Visicol, please talk with the doctor, pharmacist, or other health care provider.
  • If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

This information should not be used to decide whether or not to take this medicine or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about Visicol. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not specific medical advice and does not replace information you receive from the healthcare provider. You must talk with the healthcare provider for complete information about the risks and benefits of using Visicol.

Review Date: October 4, 2017

Visicol Description

Visicol® (sodium phosphate monobasic monohydrate, USP, and sodium phosphate dibasic anhydrous, USP) is a purgative used to clean the colon prior to colonoscopy. Visicol Tablets are white to off-white compressed tablets, with a monogram "I" on each side of the upper surface and a plain lower surface. Each tablet contains 1.102 grams of sodium phosphate monobasic monohydrate, USP and 0.398 grams of sodium phosphate dibasic anhydrous, USP for a total of 1.5 grams of sodium phosphate per tablet. Inert ingredients include microcrystalline cellulose (MCC), NF; magnesium stearate, NF; and colloidal silicon dioxide, NF. Visicol is gluten-free.

The structural and molecular formulae and molecular weights of the active ingredients are shown below:

  • Sodium phosphate monobasic monohydrate, USP

    Molecular Formula: NaH2PO4•H2O
    Molecular Weight: 137.99
  • Sodium phosphate dibasic anhydrous, USP

    Molecular Formula: Na2HPO4
    Molecular Weight: 141.96

Visicol Tablets are for oral administration only.


Visicol Tablets are contraindicated in patients with biopsy-proven acute phosphate nephropathy.

Visicol Tablets are contraindicated in patients with a known allergy or hypersensitivity to sodium phosphate salts or any of its ingredients.

Visicol Dosage and Administration

The recommended dose of Visicol Tablets for colon cleansing for adult patients is 40 tablets (60 grams of sodium phosphate) taken orally with a total of 3.6 quarts of clear liquids in the following manner:

  The evening before the colonoscopy procedure: Take 3 Visicol Tablets (the last dose will be 2 Visicol Tablets) with 8 ounces of clear liquids every 15 minutes for a total of 20 tablets.

  On the day of the colonoscopy procedure: Starting 3-5 hours before the procedure, take 3 Visicol Tablets (the last dose will be 2 Visicol Tablets) with 8 ounces of clear liquids every 15 minutes for a total of 20 tablets.

It is recommended that patients receiving Visicol be advised to adequately hydrate before, during, and after the use of Visicol.

Patients should not use Visicol within seven days of previous administration. No additional enema or laxative is required, and patients should be advised NOT to take additional agents, particularly those containing sodium phosphate.