sodium acid phosphate (Rx)

Brand and Other Names:OsmoPrep, Phospho Soda, more...sodium biphosphate, sodium phosphate, Visicol
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Dosing & Uses

AdultPediatric

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

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Interactions

Interaction Checker

and sodium acid phosphate

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    Contraindicated

      Serious - Use Alternative

        Significant - Monitor Closely

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            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)

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              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

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              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)

              Carefully follow dosing regimen as recommended (pm/am split dose) with adequate hydration

              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, toxic colitis, toxic megacolon, acute phosphate nephropathy

              Cautions

              Should not be readministered for at least 7 days

              Risk of acute phosphate nephropathy

              Osmotic laxative products may produce colonic mucosal ulcerations, and there have been reports of more serious cases of ischemic colitis requiring hospitalization

              QT interval prolongation reported

              Use caution in heart failure, unstable angina, cardiomyopathy, patients at risk for arrhythmias, patients with pre-existing electrolyte disturbances, gastric retention or hypomotility, severe chronic constipation, colitis, or ileus, chronic inflammatory bowel disease, or history of seizures

              Severe dehydration and electrolyte abnormalities associated with serious complications (eg, acute kidney injury, arrhythmias, and death) have occurred in adults and children who overdosed using oral or rectal over-the-counter (OTC) sodium phosphate solutions to treat constipation

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              Pregnancy & Lactation

              Pregnancy Category: C

              Lactation: Use caution

              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.

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              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%

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              Images

              BRAND FORM. UNIT PRICE PILL IMAGE
              OsmoPrep oral
              -
              1.5 gram tablet

              Copyright © 2010 First DataBank, Inc.

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              Patient Handout

              Patient Education
              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 persist or worsen, 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.Persistent diarrhea or vomiting may result in dehydration and electrolytes 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: severe or persistent stomach/abdominal pain, 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.Laboratory and/or medical tests (such as blood mineral levels, EKG, kidney function) may be performed to monitor your progress or check for side effects. 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 August 2021. Copyright(c) 2021 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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              Formulary

              FormularyPatient Discounts

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              The above information is provided for general informational and educational purposes only. Individual plans may vary and formulary information changes. Contact the applicable plan provider for the most current information.

              Tier Description
              1 This drug is available at the lowest co-pay. Most commonly, these are generic drugs.
              2 This drug is available at a middle level co-pay. Most commonly, these are "preferred" (on formulary) brand drugs.
              3 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs.
              4 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
              5 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
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              NC NOT COVERED – Drugs that are not covered by the plan.
              Code Definition
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              Drugs that require prior authorization. This restriction requires that specific clinical criteria be met prior to the approval of the prescription.
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              Drugs that have quantity limits associated with each prescription. This restriction typically limits the quantity of the drug that will be covered.
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              Drugs that have step therapy associated with each prescription. This restriction typically requires that certain criteria be met prior to approval for the prescription.
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              Medscape prescription drug monographs are based on FDA-approved labeling information, unless otherwise noted, combined with additional data derived from primary medical literature.