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 of potassium phosphate (as buffered mix of K2HPO4 and KH2PO4) is relatively safe when renal function is well preserved.