Dosing & Uses
Dosage Forms & Strengths
monobasic sodium phosphate monohydrate / dibasic sodium phosphate heptahydrate
aqueous solution
- (48g/18g)/100mL
tablet
- 0.398g/1.102g
enema
- (7g/19g)/118mL
Bowel Preparation for Colonoscopy
OsmoPrep: 4 tablets with 8 oz of water PO q15min (total 20 tablets) evening before procedure, and repeat regimen (12 tablets) next day 3-5 hours before procedure
Visicol: 3 tablets with 8 oz of water PO q15min (last dose 2 tablets, total 20 tablets) evening before procedure, and repeat same regimen next day 3-5 hours before procedure
Aqueous: 30-45 mL (of 48 g Na2HPO4-18 g NaH2PO4/100 mL) PO x2 10-12 hours apart; each dose with at least 8 oz liquid; each dose followed by additional minimum 16 oz liquid; 2nd dose at least 3 hours before procedure
Laxative
PR: Administer contents of 4.5 oz enema rectally as single dose
PO: Administer 15 mL as single dose qDay; not to exceed 45 mL/day
Dosage Forms & Strengths
monobasic sodium phosphate monohydrate / dibasic sodium phosphate heptahydrate
aqueous solution
- (48g/18g)/100mL
tablet
- 0.398g/1.102g
enema
- (7g/19g)/118mL
pediatric enema
- (3.5g/9.5g)/59mL
Bowel Preparation for Colonoscopy (No Standard Regimen; One Recommended)
<15 kg: 22.5 mL aqueous PO afternoon and evening before colonoscopy
≥15 kg: 45 mL aqueous PO afternoon and evening before colonoscopy
Laxative (Rectal)
<2 years: Safety and efficacy not established
2-4 years: Administer one half content of 2.25 oz pediatric enema as single dose
4-12 years: Administer contents of 2.25 oz pediatric enema as single dose
≥12 years: Administer contents of 4.5 oz enema rectally as single dose
Laxative (Oral)
<5 years: Safety and efficacy not established
5-10 years: 7.5 mL as single dose; not to exceed 7.5 mL/day
10-12 years: 15 mL as single dose; not to exceed 15 mL/day
≥12 years: 15 mL as single dose qDay; not to exceed 45 mL/day
Interactions
Interaction Checker
No Results
Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor
Contraindicated (1)
- sodium phosphate rectal
sodium phosphate rectal, sodium acid phosphate. Either increases effects of the other by pharmacodynamic synergism. Contraindicated. Either increases toxicity of the other. Coadministration of various sodium phosphate preparations are known to cause electrolyte disturbances and hypovolemia.
Serious - Use Alternative (2)
- baloxavir marboxil
sodium acid phosphate will decrease the level or effect of baloxavir marboxil by cation binding in GI tract. Avoid or Use Alternate Drug. Baloxavir may bind to polyvalent cations resulting in decreased absorption. Studies in monkeys showed concurrent use with calcium, aluminum, or iron caused significantly decreased plasma levels. Human studies not conducted.
- potassium phosphates, IV
sodium acid phosphate and potassium phosphates, IV both increase serum potassium. Avoid or Use Alternate Drug.
Monitor Closely (7)
- deflazacort
sodium acid phosphate and deflazacort both decrease serum potassium. Use Caution/Monitor.
- dextroamphetamine
sodium acid phosphate decreases levels of dextroamphetamine by increasing renal clearance. Use Caution/Monitor.
- lisdexamfetamine
sodium acid phosphate decreases levels of lisdexamfetamine by increasing renal clearance. Use Caution/Monitor.
- methamphetamine
sodium acid phosphate decreases levels of methamphetamine by increasing renal clearance. Use Caution/Monitor.
- methylenedioxymethamphetamine
sodium acid phosphate decreases levels of methylenedioxymethamphetamine by increasing renal clearance. Use Caution/Monitor.
- omadacycline
sodium acid phosphate will decrease the level or effect of omadacycline by inhibition of GI absorption. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Multivalent cation-containing products may impair absorption of tetracyclines, which may decrease its efficacy. Separate dosing of tetracyclines from these products.
- sarecycline
sodium acid phosphate will decrease the level or effect of sarecycline by inhibition of GI absorption. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Multivalent cation-containing products may impair absorption of tetracyclines, which may decrease its efficacy. Separate dosing of tetracyclines from these products.
Minor (0)
Adverse Effects
Frequency Not Defined
Possible QT interval prolongation due to electrolyte imbalance
Aspiration
Dizziness
Headache
Abdominal pain
Vomiting
Mucosal bleeding
Bloating
Colonic mucosal ulceration
Nausea
Electrolyte imbalance: hyperphosphatemia, hypocalcemia, hypernatremia, hypokalemia
Metabolic acidosis, dehydration
Acute phosphate nephropathy
Cardiac arrhythmia
Facial edema
Warnings
Black Box Warnings
Rare reports of acute phosphate nephropathy with oral sodium phosphate products used for colon cleansing before colonoscopy
Some cases have resulted in permanent renal function impairment requiring long-term hemodialysis
Risk factors for acute phosphate nephropathy include age >55 yr, hypovolemia, baseline kidney disease, bowel obstruction, active colitis, and those using medicines that affect renal perfusion or function (eg, diuretics, ACE inhibitors, ARBs, NSAIDs)
Advise patients of the importance of following the recommended split dosage regimen and importance of adequate hydration before, during, and after the use of this product; avoid additional sodium phosphate-based purgative or enema products
Contraindications
Enema: Renal failure, CHF, ascites, obstruction, megacolon, perforated bowel, ulcerative colitis, fecal impaction
IV: Hyperphosphatemia, hypocalcemia, hypernatremia
Oral: Bowel obstruction, bowel perforation, gastric bypass or stapling surgery, toxic colitis, toxic megacolon, acute phosphate nephropathy
Cautions
If gastrointestinal obstruction or perforation suspected, perform appropriate diagnostic studies to rule out these conditions before administering product; use with caution in patients with severe active ulcerative colitis
Patients with impaired gag reflex or other swallowing abnormalities are at risk for regurgitation or aspiration; observe these patients during administration of product
This product may cause serious hypersensitivity reactions including anaphylaxis, angioedema, rash, urticaria, and throat tightness; inform patients of signs and symptoms of anaphylaxis and instruct them to seek immediate medical care should signs and symptoms occur
Renal disease, acute phosphate nephropathy, electrolyte disorders
There have been rare, but serious, reports of renal failure, acute phosphate nephropathy, and nephrocalcinosis in patients receiving this product for colon cleansing prior to colonoscopy; these cases often resulted in permanent impairment of renal function and several patients required long-term dialysis
The time to onset is typically within days; however, in some cases, the diagnosis of these events has been delayed up to several months after the ingestion of these products
Patients at increased risk of acute phosphate nephropathy may include patients with the following: hypovolemia, baseline kidney disease, increased age, and patients using medicines that affect renal perfusion or function, including diuretics, angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers, and possibly nonsteroidal anti-inflammatory drugs (NSAIDs)
Electrolyte disorders
- Bowel preparations can cause fluid and electrolyte disturbances, which can lead to serious adverse reactions including cardiac arrhythmias, seizures and renal impairment
-
Patient management
- Use with caution in patients with severe renal impairment (creatinine clearance < 30 mL/minute), with conditions, or who are taking medications, that increase risk for fluid and electrolytedisturbances or may increase risk of arrhythmias, seizures, or renal impairment
- Consider performing baseline and post-colonoscopy labs (phosphate, calcium, potassium, sodium, creatinine, and BUN) in these patients
- Correct electrolyte abnormalities such as hypernatremia, hyperphosphatemia, hypokalemia, or hypocalcemia before treatment
- Avoid additional sodium phosphate-based purgative or enema products
- Advise all patients to hydrate adequately before, during, and after use of this product
- If a patient develops significant vomiting or signs of dehydration while or after taking this product, consider performing post-colonoscopy lab tests, including electrolytes, creatinine, and blood urea nitrogen (BUN)
Cardiac arrhythmias
- Serious arrhythmias associated with use of ionic osmotic laxative products for bowel preparation. QT prolongation rarely reported with sodium phosphate tablets and associated with electrolyte imbalances, such as hypokalemia and hypocalcemia
- Use caution when prescribing product for patients at increased risk of arrhythmias (eg, patients with a history of prolonged QT, uncontrolled arrhythmias, recent myocardial infarction, unstable angina, congestive heart failure, or cardiomyopathy) and those taking medications known to prolong the QT interval; serious complications may occur; consider pre-dose and post-colonoscopy ECGs s in patients at increased risk of serious cardiac arrhythmias
Seizures
- There have been rare reports of generalized tonic-clonic seizures and/or loss of consciousness associated with use of sodium phosphate osmotic laxative products in patients with no prior history of seizures
- The seizure cases were associated with electrolyte abnormalities (eg, hyponatremia, hypokalemia, hypocalcemia, and hypomagnesemia) and low serum osmolality; the neurologic abnormalities resolved with correction of fluid and electrolyte abnormalities
- Use with caution in patients with a history of seizures and in patients at higher risk of seizure, such as patients taking medications that lower the seizure threshold (such as tricyclic antidepressants), patients withdrawing from alcohol or benzodiazepines, or patients with known or suspected hyponatremia
Colonic mucosal ulceration and inflammatory bowel disease
- Osmotic laxatives may induce colonic mucosal aphthous ulcerations; in the program, aphthous ulcers were observed in 3% of patients who took recommended dosing regimen
- Consider potential for mucosal ulcerations resulting from bowel preparation when interpreting colonoscopic finding in patients with known or suspected inflammatory bowel disease
- Use caution in patients experiencing an acute exacerbation of chronic inflammatory bowel disease as published data suggest that sodium phosphate absorption may be enhanced in such patients
Pregnancy & Lactation
Pregnancy
There are no available data on sodium phosphate use in pregnant women to inform a drug-associated risk for adverse developmental outcomes
Animal data
- Animal reproduction studies have not been conducted with sodium phosphate
Lactation
There are no data available to assess presence of sodium phosphate in human milk, effects of drug on breastfed infant, or on milk production; the lack of clinical data during lactation precludes a clear determination of risk of this product to a child during lactation
The developmental and health benefits of breastfeeding should be considered along with mother’s clinical need for OsmoPrep and any potential adverse effects on breastfed child from this product or from underlying maternal condition
Pregnancy Categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk. C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done. D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk. X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist. NA: Information not available.Pharmacology
Mechanism of Action
Draws water into the lumen of the gut where it causes osmotic effect; causes abdominal distention and promotes peristalsis and evacuation of the bowel
Absorption
1-20%
Onset: 2-5 min (rectal); 3-6 hr (cathartic)
Elimination
Excretion: Urine: 90%
Images
| BRAND | FORM. | UNIT PRICE | PILL IMAGE |
|---|---|---|---|
| OsmoPrep oral - | 1.5 gram tablet |  |
Copyright © 2010 First DataBank, Inc.
Patient Handout
sod phos mono-sod phos dibasic oral
SODIUM PHOSPHATE MONOBASIC/DIBASIC - ORAL
(SOE-dee-um FOS-fate MAW-no-BAY-sik/dye-BAY-sik)
COMMON BRAND NAME(S): OsmoPrep
WARNING: Rarely, serious kidney problems have occurred with the use of this product. Kidney disease, bowel problems (such as colitis or obstruction), severe loss of body water (dehydration), or being older than 55 years can increase the risk. Taking certain medications that can affect the kidneys (see Drug Interactions section) can also increase the risk. If any of these cautions apply to you, talk with your doctor before using this drug. Drink plenty of clear fluids to help prevent dehydration.
USES: This medication is used to clean out the intestines before a colonoscopy. Sodium phosphate is a laxative that works by drawing large amounts of water into the colon, causing you to have watery bowel movements. This cleans out the intestines so that your doctor can clearly view them during your colonoscopy.This medication should not be used for weight loss or constipation due to the possibility of severe side effects.
HOW TO USE: Read the Medication Guide provided by your pharmacist before you start taking this medication and each time you get a refill. If you have any questions, consult your doctor or pharmacist.Your doctor should tell you how long before the procedure you should take this product. Follow your doctor's directions closely. If you have any questions, ask your doctor or pharmacist.Follow any special dietary instructions given by your doctor. A period of not eating is usually recommended before you start taking this medication and lasting until after the colonoscopy. Only clear liquids (such as water, flavored water, lemonade with no pulp, ginger ale, apple juice) are allowed during this time. Do not drink any liquids colored purple or red.The evening before your colonoscopy, take 4 tablets with at least 8 ounces (240 milliliters) of clear liquid by mouth every 15 minutes or as directed by your doctor. Repeat this dose and the liquids every 15 minutes until you have taken 5 doses (20 tablets). The next day, start taking the medication 3-5 hours before the colonoscopy. Take 4 tablets every 15 minutes with liquids as directed until you have taken 3 doses (12 tablets).Dosage is based on your medical condition, procedure, and response to treatment. Do not use a higher dose or more often than directed by your doctor.This drug may decrease your absorption of other medications. Take your other medications as directed by your doctor, usually at least 1 hour before or 1 hour after taking this drug. Ask your doctor or pharmacist for more information or if you have any questions.Do not use any other laxative products (especially sodium phosphate) while taking this product or for 7 days after treatment is finished. Doing so may increase your risk for severe side effects.Watery bowel movements usually begin 1 hour after you start to take the tablets. The bowel movements can be very large and watery. Drink as many clear liquids as you can before, during, and after taking this medication so that you do not become dehydrated. Doing so will help prevent serious side effects (such as kidney problems). Consult your doctor or pharmacist for more information.The watery bowel movements from sodium phosphate may decrease the absorption of your regular medicines. Consult your doctor or pharmacist about how to minimize this effect.Contact your doctor if you do not have a bowel movement within 3 hours after taking this medication.
SIDE EFFECTS: Nausea, vomiting, stomach/abdominal pain or bloating, dizziness, and headache may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.Vomiting/diarrhea that doesn't stop may result in dehydration and electrolyte imbalance. This may cause serious side effects to the kidneys and heart. Contact your doctor promptly if you notice any symptoms of dehydration, such as unusual decreased urination, unusual dry mouth/increased thirst, lack of tears, dizziness/lightheadedness, muscle weakness/cramping, or pale/wrinkled skin.Tell your doctor right away if you have any serious side effects, including: stomach/abdominal pain that is severe or doesn't go away, black/bloody stools, rectal bleeding, mental/mood changes (such as confusion, unusual drowsiness).Get medical help right away if you have any very serious side effects, including: fast/irregular heartbeat, chest pain, fainting, seizures.A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.In the US -Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
PRECAUTIONS: See also How to Use section.Before taking sodium phosphate, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.Before using this medication, tell your doctor or pharmacist your medical history, especially of: heart problems (such as heart failure, irregular heartbeat, QT prolongation in the EKG, chest pain, heart attack or heart surgery within the last 3 months), stomach/bowel problems (such as blockage, irritable bowel disease, ulcerative colitis, severe constipation), gastric bypass/stapling, low blood minerals, dehydration, kidney problems, liver problems (such as cirrhosis, fluid build-up in the abdomen), salt restricted diet, daily alcohol or sedative use, seizure problem, swallowing problems (such as narrowing of the swallowing tube/esophagus).Before having surgery, tell your doctors or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).Caution is advised when using this drug in older adults because they may be more sensitive to the effects of the drug, especially kidney problems, dehydration, severe dizziness, fainting, and fast/irregular heartbeat.During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.It is unknown if this drug passes into breast milk. Consult your doctor before breast-feeding.
DRUG INTERACTIONS: See also How to Use section.Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.Some products that may interact with this drug include: burosumab, drugs that may affect the kidneys (including ACE inhibitors such as lisinopril, ARBs such as valsartan, diuretics/"water pills" such as furosemide/hydrochlorothiazide, NSAIDs such as ibuprofen/naproxen).
OVERDOSE: If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center.
NOTES: Do not share this medication with others.Lab and/or medical tests (such as blood mineral levels, EKG, kidney function) may be done while you are taking this medication. Keep all medical and lab appointments. Consult your doctor for more details.
MISSED DOSE: This medication should be used as scheduled. If you miss a dose, contact your doctor or pharmacist for instructions. Do not double the dose to catch up.
STORAGE: Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.
Information last revised December 2022. Copyright(c) 2023 First Databank, Inc.
IMPORTANT: HOW TO USE THIS INFORMATION: This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.
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