endocrine and metabolic disorders
Hypophosphatemia
Treatment of Hypophosphatemia
Treat underlying disorder Oral phosphate replacement IV phosphate when serum phosphate is<1 mg/dL (< 0.32 mmol/L) or symptoms are severe Removal of the cause of hypophosphatemia may include stopping phosphate-binding antacids or diuretics or correcting hypomagnesemia. Treatment of the underlying disorder and oral phosphate replacement are usually adequate in asymptomatic patients, even when the serum concentration is very low. Phosphate can be given in doses up to about 1 g orally 3 times a day in tablets containing sodium phosphate orpotassium phosphate. Oral sodium phosphate orpotassium phosphatemay be poorly tolerated because of diarrhea. Ingestion of 1 L of low-fat or skim milk provides 1 g of phosphate and may be more acceptable. Parenteral phosphate is usually given IV. It should be administered in any of the following circumstances: When serum phosphate is<1 mg/dL (< 0.32 mmol/L) Rhabdomyolysis , hemolysis, or central nervous system symptoms are present Oral replacement is not feasible due to underlying disorder IV administration ofpotassium phosphate(as buffered mix of K2HPO4 and KH2PO4) is relatively safe when renal function is well preserved. Parenteralpotassium phosphatecontains 93 mg (3 mmol) phosphorus and 170 mg (4.4 mEq or 4.4 mmol) potassium per mL. The usual dose is 0.5 mmol phosphorus/kg (0.17 mL/kg) IV over 6 hours. Patients with alcohol use disorder may require≥1 g/day during total parenteral nutrition; supplemental phosphate is stopped when oral intake is resumed. If patients have impaired renal function or serum potassium > 4 mEq/L (> 4 mmol/L), sodium phosphate preparations generally should be used; these preparations also contain 3 mmol/mL of phosphorus and are thus given at the same dose. Serum calcium and phosphate concentrations should be monitored during therapy, particularly when phosphate is given IV or to patients with impaired renal function. In most cases, no more than 7 mg/kg (about 500 mg for a 70-kg adult) of phosphate should be given over 6 hours. Close monitoring is done, and more rapid rates of phosphate administration should be avoided to prevent Hypocalcemia , 