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Phosphate Laxative Side Effects

Generic name: sodium biphosphate / sodium phosphate

Medically reviewed by Last updated on Jun 4, 2023.

Note: This document contains side effect information about sodium biphosphate / sodium phosphate. Some dosage forms listed on this page may not apply to the brand name Phosphate Laxative.

Applies to sodium biphosphate / sodium phosphate: oral solution, oral tablet. Other dosage forms:


Oral route (Tablet)

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. OsmoPrep®: 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®: It is important to use the dose and dosing regimen as recommended (pm/am split dose)..

Serious side effects of Phosphate Laxative

Along with its needed effects, sodium biphosphate / sodium phosphate 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 while taking sodium biphosphate / sodium phosphate:

More common

  • Bloating
  • stomach pain

Incidence not known

  • Agitation
  • bloody or cloudy urine
  • burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
  • confusion
  • cough
  • decrease in the frequency or amount of urine
  • decreased awareness or responsiveness
  • depression
  • difficult or labored breathing
  • difficult or painful urination
  • difficulty with swallowing
  • dizziness
  • fainting
  • fast, slow, or irregular heartbeat
  • headache
  • hives, itching, skin rash
  • hostility
  • increased blood pressure
  • increased thirst
  • irritability
  • 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
  • nausea
  • noisy breathing
  • puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
  • rapid weight gain
  • redness of the skin
  • seizures
  • 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
  • vomiting

Get emergency help immediately if any of the following symptoms of overdose occur while taking sodium biphosphate / sodium phosphate:

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
  • lightheadedness
  • 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
  • restlessness
  • stomach cramps
  • sunken eyes
  • sweating
  • tremor
  • weakness
  • weight gain
  • wrinkled skin

For Healthcare Professionals

Applies to sodium biphosphate / sodium phosphate: oral solution, oral tablet, rectal enema.


The most common adverse events were abdominal bloating, nausea, abdominal pain, and vomiting.[Ref]


Very common (10% or more): Bloating (39%), nausea (37%), abdominal pain (24%), vomiting (10%)[Ref]


Postmarketing reports: Renal impairment, increased blood urea nitrogen (BUN), increased creatinine, acute renal failure, acute phosphate nephropathy, nephrocalcinosis, renal tubular necrosis[Ref]

Nervous system

Postmarketing reports: Seizures[Ref]


Postmarketing reports: Arrhythmias[Ref]


Postmarketing reports: Hypersensitivity reactions (including anaphylaxis, rash, pruritus, urticaria, throat tightness, bronchospasm, dyspnea, pharyngeal edema, dysphagia, paresthesia, swelling of the lips and tongue, and facial swelling)[Ref]

More about Phosphate Laxative (sodium biphosphate / sodium phosphate)

Patient resources

Other brands

Fleet Enema, Disposable Enema, OsmoPrep, Fleet Phospho Soda, Visicol

Professional resources

Related treatment guides


1. Product Information. OsmoPrep (sodium acid phophate-sodium phosphate). Valeant Pharmaceuticals. 2018.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.