Sodium Phosphate and Breastfeeding

Summary of use during lactation

Phosphate is a normal constituent of breastmilk. Phosphate concentrations have not been measured in breastmilk after large maternal doses of sodium phosphate, such a 30 gram oral dose for pre-procedural bowel evacuation. However, the added phosphate in breastmilk is likely to be only about 130 mg over 24 hours in this situation. The increase from a typical dose of a rectal enema would be considerably less than this amount. Breastmilk sodium concentration is tightly regulated, and will not be affected. It is probably not necessary to suspend breastfeeding after the use of oral sodium phosphate solutions given once or twice for bowel evacuation before a procedure. Use of a phosphate rectal enema by a nursing mother would require no special precautions.

Drug levels in milk and infant serum

Phosphate is a normal constituent of breastmilk.[1,2] Infants normally receive about 130 mg of inorganic phosphate daily from breastmilk.[2] Maternal Levels. Administration of a 30 gram dose of oral sodium phosphate solution (e.g., Visicol) approximately doubles the maternal serum phosphate concentration, with serum concentrations returning to baseline about 24 hours after the dose.[3,4] Assuming breastmilk phosphate concentration also doubles, the increased phosphate dose to the infant would be only 130 mg for one day. Administration of a phosphate enema (2 Fleet Enemas, containing a total of 14 grams of sodium phosphate dibasic and 38 grams of sodium phosphate monobasic) to 33 subjects increased serum phosphate by an average of about 25% (range 0.1 to 2.5 mg/dL).[5] In one other patient, a phosphate enema (Practo Clyss 120, containing a total of 7.2 grams of sodium phosphate dibasic and 19.2 grams of sodium phosphate monobasic) increased serum phosphate by 35% (by 0.8 mmol/L) after a single dose.[6] Infant Levels. Relevant published information was not found as of the revision date.

Effects in breastfed infants

Relevant published information was not found as of the revision date.

Effects on lactation and breastmilk

Relevant published information was not found as of the revision date.

References

1. KentJC ArthurPG RetallackRW Calcium, phosphate and citrate in human milk at initiation of lactation. J Dairy Res 1992 59 161 7 1613174 PubMed
2. AllenJC KellerRP ArcherP Studies in human lactation: Milk composition and daily secretion rates of macronutrients in the first year of lactation. Am J Clin Nutr 1991 54 69 80 2058590 PubMed
3. Visicol package insert. Salix Pharmaceuticals, Inc; December 2010.
4. EhrenpreisED Increased serum phosphate levels and calcium fluxes are seen in smaller individuals after a single dose of sodium phosphate colon cleansing solution: a pharmacokinetic analysis. Aliment Pharmacol Ther 2009 29 1202 11 19298584 PubMed
5. SchuchmannGD BarciaPJ Phosphate absorption from fleet enemas in adults. Curr Surg 1989 46 120 2 2736963 PubMed
6. RimensbergerP SchubigerG WilliU Connatal rickets following repeated administration of phosphate enemas in pregnancy: a case report. Eur J Pediatr 1992 151 54 6 1728548 PubMed