Generic name: sodium phosphate dibasic and sodium phosphate monobasic [ SOE-dee-um-FOS-fate, dye-BAY-sik, SOE-dee-um-FOS-fate, mono-BAY-sik ]
Drug class: Laxatives
Medically reviewed by Drugs.com. Last updated on Aug 21, 2023.
Acute phosphate nephropathy has been reported in association with the use of oral sodium phosphate products, some cases resulting in permanent impairment of renal function, including cases requiring long-term dialysis. Risk factors for developing acute phosphate nephropathy include increased age, hypovolemia, renal impairment, bowel obstruction, or active colitis. Use of medications that may impair renal perfusion or function may also increase risk. These include diuretics, ACE inhibitors, angiotensin receptor blockers (ARBs), and possibly NSAIDs. However, cases have occurred in patients with no identifiable risk factors . Osmo
Prep(R): Advise patients of the importance of following the recommended split dosage regimen and the importance of adequate hydration before, during and after the use of sodium phosphate, dibasic and sodium phosphate, monobasic. Avoid additional sodium phosphate-based purgative or enema products . Visicol(R): It is important to use the dose and dosing regimen as recommended (pm/am split dose)..
Uses for Phospho-Soda
Sodium phosphate dibasic and sodium phosphate monobasic combination is used to clean or empty your bowels before an imaging procedure called colonoscopy. This medicine works by cleaning your colon and causing you to have diarrhea. This helps your doctor see the inside of your colon more clearly during the colonoscopy.
This medicine is available only with your doctor's prescription.
Before using Phospho-Soda
In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:
Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.
Appropriate studies have not been performed on the relationship of age to the effects of OsmoPrep® tablets in the pediatric population. Safety and efficacy have not been established.
Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of OsmoPrep® tablets in the elderly. However, elderly patients may be more sensitive to the effects of OsmoPrep® tablets than younger adults, and are more likely to have age-related kidney problems, which may require caution for patients receiving this medicine.
There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.
Interactions with Medicines
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.
Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Aripiprazole Lauroxil
- Arsenic Trioxide
- Inotuzumab Ozogamicin
Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Aluminum Carbonate, Basic
- Aluminum Hydroxide
- Aluminum Phosphate
- Calcium Acetate
- Calcium Carbonate
- Calcium Citrate
- Dihydroxyaluminum Aminoacetate
- Dihydroxyaluminum Sodium Carbonate
- Magnesium Carbonate
- Magnesium Hydroxide
- Magnesium Oxide
- Magnesium Trisilicate
Interactions with Food/Tobacco/Alcohol
Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.
Other Medical Problems
The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:
- Acute phosphate nephropathy (serious kidney problem caused by too much phosphate), biopsy-proven or
- Stomach or bowel problems (eg, blockage, perforation) or
- Stomach surgery (eg, bypass, stapling) or
- Toxic colitis (inflammation of the colon) or
- Toxic megacolon (severe irritation of the colon)—Should not be used in patients with these conditions.
- Angina (severe chest pain), unstable or
- Congestive heart failure or
- Heart attack, recent or
- Heart disease (eg, cardiomyopathy) or
- Heart rhythm problems (eg, prolonged QT interval, poorly-controlled arrhythmia), history of—May increase risk of arrhythmia.
- Arrhythmia (heart rhythm problem) or
- Dehydration or
- Electrolyte imbalance (eg, high or low calcium, phosphate, potassium, or sodium in the blood) or
- Hypovolemia (low blood volume) or
- Inflammatory bowel disease, history of or
- Seizures, history of or
- Trouble with swallowing or gastric reflex or
- Ulcerative colitis or
- Withdrawal from alcohol or benzodiazepines—Use with caution. May make these conditions worse.
Proper use of Phospho-Soda
Take this medicine exactly as directed by your doctor. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered.
This medicine should come with a Medication Guide. Read and follow these instructions carefully. Ask your doctor if you have any questions.
Take each dose (4 tablets) with 8 ounces of clear liquids. Examples of clear liquids include: water, flavored water, clear broth, herbal tea, black tea, coffee, clear soda, gelatin, popsicles, lemonade (no pulp), ginger ale, white grape juice, or apple juice. Do not eat or drink alcohol, milk, anything colored purple or red, or any foods that have pulp.
Eat or drink only clear liquids after 12:00 PM (noon) on the day before and until after your colonoscopy. Do not eat solid food.
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 and help soften your bowel movements, making them easier to pass.
Do not take any oral medicines within 1 hour before or after each dose of OsmoPrep®.
Do not take this medicine if you have already used it in the last 7 days. Your doctor will tell you if you need to use this medicine again.
The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.
The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.
- For oral dosage form (tablets):
- For cleansing of the colon:
- Evening before the colonoscopy: Four tablets with 8 ounces (oz.) of clear liquids every 15 minutes (for a total of 20 tablets).
- Day of colonoscopy (starting 3 to 5 hours before the procedure): Four tablets with 8 oz. of clear liquids every 15 minutes (for a total of 12 tablets).
- Children—Use and dose must be determined by your doctor.
- For cleansing of the colon:
Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.
Keep out of the reach of children.
Do not keep outdated medicine or medicine no longer needed.
Ask your healthcare professional how you should dispose of any medicine you do not use.
Precautions while using Phospho-Soda
It is very important that your doctor check your progress after taking this medicine. This will allow your doctor to see if the medicine is working properly. Blood and urine tests and an electrocardiogram (ECG) may be needed to check for unwanted effects.
Do not take this medicine together with other laxatives or enemas containing sodium phosphate. Doing so may lead to serious unwanted effects.
This medicine may cause serious kidney problems. These are more likely to occur if you are over 55 years of age, dehydrated, have low blood volume, and are taking medicines that could be hard on your kidneys (eg, diuretics or water pills, certain blood pressure medicines, NSAID pain or arthritis medicine). Check with your doctor right away if you have bloody urine, a decrease in the amount or frequency of urine, lower back or side pain, trouble breathing, weight gain, or swelling of the face, fingers, and lower legs.
Taking more than one dose of over-the-counter (OTC) sodium phosphate medicine in 24 hours may cause serious kidney and heart problems. Check with your doctor if you have the following symptoms: confusion, decreased urination, dizziness, dry mouth, fainting, increase in heart rate, rapid breathing, or unusual tiredness or weakness.
Contact your doctor right away if you have any changes to your heart rhythm. You might feel dizzy or faint, or you might have a fast, pounding, or uneven heartbeat. Make sure your doctor knows if you had a heart rhythm problem, such as QT prolongation.
This medicine may cause serious allergic reactions, including anaphylaxis and angioedema, which can be life-threatening and require immediate medical attention. Tell your doctor right away if you have a rash, itching, hoarseness, trouble breathing, trouble swallowing, or any swelling of your hands, face, or mouth after using this medicine.
Call your doctor right away if you have any unusual symptoms that concern you, such as bloating, abdominal or stomach pain, seizures, nausea, vomiting, or headache.
Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.
Side Effects of Phospho-Soda
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur:
- stomach pain
Incidence not known
- bloody or cloudy urine
- burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
- decrease in the frequency or amount of urine
- decreased awareness or responsiveness
- difficult or labored breathing
- difficult or painful urination
- difficulty with swallowing
- fast, slow, or irregular heartbeat
- hives, itching, skin rash
- increased blood pressure
- increased thirst
- large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or genitals
- loss of appetite
- loss of consciousness
- lower back or side pain
- muscle twitching
- noisy breathing
- puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
- rapid weight gain
- redness of the skin
- severe sleepiness
- sudden decrease in the amount of urine
- swelling of the face, ankles, or hands
- tightness in the chest
- unusual drowsiness, dullness, tiredness, weakness, or feeling of sluggishness
Get emergency help immediately if any of the following symptoms of overdose occur:
Symptoms of overdose
- Blurred vision
- chest pain or discomfort
- decreased frequency of urine
- dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
- dry mouth
- increase in heart rate
- increased thirst
- loss of appetite
- lower back or side pain
- muscle cramps in the hands, arms, feet, legs, or face
- muscle pain
- pounding or rapid pulse
- rapid breathing
- stomach cramps
- sunken eyes
- weight gain
- wrinkled skin
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
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- Check interactions
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- Side effects
- Dosage information
- During pregnancy
- Drug class: laxatives
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