sodium phosphates (sodium phosphate and sodium biphosphate)
Fleet Phospho-soda

Pharmacologic classification: acid salt
Therapeutic classification: saline laxative
Pregnancy risk category C

Available forms
Available without a prescription
Solution: 2.4 g monobasic sodium phosphate and 9 g dibasic sodium phosphate/5 ml

Indications and dosages
 Constipation. Adults and children age 12 and older: 20 to 45 ml daily.
Children ages 10 to 11: 10 to 20 ml daily.
Children ages 5 to 9: 5 to 10 ml daily.

Laxative action: Sodium phosphate and sodium biphosphate exert an osmotic effect in the small intestine by drawing water into the intestinal lumen, producing distention that promotes peristalsis and bowel evacuation.

Absorption: The extent of phosphate and sodium absorption from oral phosphate laxatives is unknown. The extent of phosphate absorption from rectally administered phosphate enemas is unknown, but about 1% to 20% of the sodium and phosphate in such preparations is reportedly absorbed.
Distribution: Unknown.
Metabolism: Unknown.
Excretion: Unknown; probably in feces and urine.

Route Onset Peak Duration
P.O. 3-6 hr Variable Variable

Contraindications and precautions
Contraindicated in patients on sodium-restricted diets and patients with abdominal pain, nausea, vomiting, or other symptoms of appendicitis or acute surgical abdomen; intestinal obstruction or perforation; edema; heart failure; megacolon; or impaired renal function. Use cautiously in patients with large hemorrhoids or anal excoriations.

Drug-drug. Antacids: May cause inactivation of both drugs. Don’t use together.

Adverse reactions
GI: abdominal cramping.
Metabolic: fluid and electrolyte disturbances (hypernatremia, hyperphosphatemia) with daily use.
Other: laxative dependence with long-term or excessive use.

Effects on lab test results
• May increase sodium and phosphate levels. May decrease electrolyte levels (with prolonged use).

Overdose and treatment
No information available. Probable clinical effects include abdominal pain and diarrhea.

Special considerations
• Dilute drug with water before giving orally (as directed by manufacturer). Follow drug administration with full glass of water.
• Drug isn’t routinely used to treat constipation but is commonly used to evacuate the bowel.
• Monitor serum electrolyte levels; when drug is given as saline laxative, up to 10% of sodium content may be absorbed.
Breast-feeding patients
• It isn’t known if drug appears in breast milk. Use cautiously in breast-feeding women.

Patient education
• Teach patient how to mix drug.
• Instruct patient about dose schedule.
• Warn patient that frequent or prolonged use of drug may lead to laxative dependence.
• Teach patient about dietary sources of bulk, which include bran and other cereals, fresh fruit, and vegetables.
• Tell patient to drink 8 oz (240 ml) of cool water after taking Fleet Phospho-soda.
• Caution patient that rectal forms aren’t intended for oral use.
• For children younger than age 5, tell parent to call before use.

Reactions may be common, uncommon, life-threatening, or COMMON AND LIFE THREATENING.
◆ Canada only
◇ Unlabeled clinical use