Dosing & Uses
Dosage Forms & Strengths
Contains mixture of monobasic sodium phosphate and dibasic sodium phosphate
enema
- (19g/7g)/118mL
- (19g/7g)/197mL
Constipation & Bowel Cleansing
Indicated as laxative in the relief of occasional constipation and as part of a bowel cleansing regimen in preparing the colon for surgery, x-ray or endoscopic examination
1 bottle PR; not to exceed 1 administration/24 hr
Administration
Remove orange protective shield from enema tip before inserting; with steady pressure, gently insert enema tip into rectum with a slight side-to-side movement, with tip pointing toward navel
Insertion may be easier if person receiving enema bears down, as if having a bowel movement; this helps relax the muscles around the anus
Do not force enema tip into rectum as this can cause injury
Squeeze bottle until nearly all liquid is gone; it is not necessary to empty the bottle completely, as it contains more liquid than needed
Remove enema tip from rectum and maintain position until urge to evacuate is strong (usually 1-5 minutes)
Do not retain enema solution for more than 10 minutes
Enema should be at room temperature before use
Positions for using this enema
- Left-side position: Lie on left side with knee bent, and arms resting comfortably
- Knee-chest position: Kneel, and then lower head and chest forward until left side of face is resting on surface with left arm folded comfortably
Dosage Forms & Strengths
Contains mixture of monobasic sodium phosphate and dibasic sodium phosphate
enema
- (9.5g/3.5g)/59mL
Constipation & Bowel Cleansing
Indicated as laxative in the relief of occasional constipation and as part of a bowel cleansing regimen in preparing the colon for surgery, x-ray or endoscopic examination
<2 years: Do not use
2-4 years: Administer one-half bottle PR of pediatric enema (ie, ~30 mL); prepare dose by unscrewing cap from bottle and removing 2 tablespoons of liquid (30 mL) with a measuring spoon, replace cap and administer remaining liquid
5-11 years: Administer 1 bottle PR of pediatric enema (ie, 59 mL)
12 years or older: Administer as in adults (adult enema)
Administration
Remove orange protective shield from enema tip before inserting; with steady pressure, gently insert enema tip into rectum with a slight side-to-side movement, with tip pointing toward navel
Insertion may be easier if person receiving enema bears down, as if having a bowel movement; this helps relax the muscles around the anus
Do not force enema tip into rectum as this can cause injury
Squeeze bottle until nearly all liquid is gone; it is not necessary to empty the bottle completely, as it contains more liquid than needed
Remove enema tip from rectum and maintain position until urge to evacuate is strong (usually 1-5 minutes)
Do not retain enema solution for more than 10 minutes
Enema should be at room temperature before use
Positions for using this enema
- Left-side position: Lie on left side with knee bent, and arms resting comfortably
- Knee-chest position: Kneel, and then lower head and chest forward until left side of face is resting on surface with left arm folded comfortably
Interactions
Interaction Checker
No Results

Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor

Contraindicated (1)
- sodium acid phosphate
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 phosphate rectal 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.
- lithium
sodium phosphate rectal decreases levels of lithium by Other (see comment). Avoid or Use Alternate Drug. Comment: Sodium phosphates may cause hypernatremia which increases lithium renal clearance; more common with large doses of oral sodium phosphate.
Monitor Closely (3)
- deflazacort
sodium phosphate rectal and deflazacort both decrease serum potassium. Use Caution/Monitor.
- omadacycline
sodium phosphate rectal 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 phosphate rectal 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
Hypersensitivity
Pruritus
Dehydration
Hyperphosphatemia
Hypocalcemia
Hypokalemia
Hypernatremia
Metabolic acidosis
Nausea
Vomiting
Abdominal pain
Abdominal distension
Diarrhea
Gastrointestinal pain
Chills
Blistering
Stinging
Anal discomfort
Proctalgia
Warnings
Contraindications
Hypersensitivity
Dehydration, renal impairment, heart failure, electrolyte abnormalities, use for bowel cleansing, bowel obstruction or pseudo, or perforation, gastric bypass or bariatric surgery, toxic megacolon, toxic colitis, or children <5 years
Cautions
Do not use laxatives when nausea, vomiting, or severe abdominal pain is present
Caution with renal impairment or ascites; increases risk of sodium retention and edema; obtain baseline and postprocedure labs in patients with renal impairment; monitor closely to avoid hyperphosphatemia
Caution in patients with a colostomy
Caution in children aged 2-11 years or elderly patients with comorbidities
Caution with pre-existing electrolyte disturbances or patients taking diuretics or other medications that may alter electrolytes
Additional liquids by mouth are recommended to prevent dehydration; inadequate fluid intake may result in hypovolemia due to excessive fluid loss
Exceeding daily dose, no return of enema solution, retention time >10 minutes, or failure to have a bowel movement within 30 minutes of enema use may lead to electrolyte disturbances, including hypernatremia, hyperphosphatemia, hypocalcemia, and hypokalemia
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
Use caution in unstable angina, cardiomyopathy, history of myocardial infarction arrhythmia, patients with or at risk for arrhythmias, including prolonged QT interval, cardiomyopathy, recent myocardial infarction; caution with other QT-prolonging drugs, consider pre-/postdose ECGs and lab tests in high-risk patients
Correct dehydration prior to using in bowel preparations
Use caution in patients with gastric retention or hypomotility, severe active ulcerative colitis or ileus, severe, chronic constipation
Use caution in history of seizures, those at high risk of seizures or on seizure therapy; obtain baseline and postprocedure labs in high-risk patients
Phosphate absorption may increase in patients with chronic inflammatory bowel disease; phosphate may induce colonic aphthous ulceration; consider this when interpreting colonoscopic findings in patients with inflammatory bowel disease
Use caution in debilitated patients, including elderly patients; evaluate patients ability to hydrate properly if receiving bowel preparation
Purgatives and laxatives can be potentially abused by bulimia nervosa patients
Use caution in patients with impaired gag reflex and those prone to aspiration or regurgitation
When used for bowel evacuation, medications may not be well absorbed due to intestinal peristalsis
Exceeding recommended doses of OTC sodium phosphate preparation to treat constipation may potentially result in serious adverse effects; renal/cardiac adverse effects reported following severe dehydration and alterations in serum electrolytes, including sodium phosphate and calcium
Pregnancy & Lactation
Pregnancy Category: C
Lactation: Unknown whether distributed in breast milk; caution because of risk for electrolyte disturbances or dehydration
Pregnant or breastfeeding patients should seek advice of health professional before using OTC drugs
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
Saline cathartic effect