Efficacy of intravenous phosphorus therapy in the severely hypophosphatemic patient

To evaluate the efficacy and safety of a simple approach to intravenous (IV) phosphorus therapy, ten adult patients with severe hypophosphatemia (less than or equal to 1 mg/dL) and normal renal function were studied prospectively. They were treated with a solution containing 9 mmole of phosphorus as monobasic potassium phosphate (KH2PO4), infused continuously every 12 hours. Serum phosphorus, potassium, and calcium levels and urinary excretion of phosphorus were measured every 12 hours. The serum phosphorus level was significantly improved at 12 hours, more than 1 mg/dL in all patients at 36 hours, and normal in six patients at 48 hours. The serum potassium level was never above normal, and serum calcium levels declined in only one patient. Administration of 9 mmole of phosphorus as KH2PO4 every 12 hours is both safe and efficacious IV therapy for severe hypophosphatemia in the adult patient with normal renal function and without hyperkalemia or hypercalcemia.