OBJECTIVE: Renal hypophosphatemic rickets is a disorder related to low levels of phosphate in plasma (hypophosphatemia). Patients with hypophosphatemia present with chronic bone and joint pain, fractures, and mineralization defects. Treatment of rickets aims to reduce bone pain, achieve normal alkaline phosphatase, and reduce leg deformities. The main pharmacological therapy in renal hypophosphatemic rickets is phosphate and vitamin D analogous supplementation. The available phosphate products include intravenous sodium phosphate, sodium/potassium phosphate, and potassium phosphate. Oral sodium phosphate solution is also commercially available. It is a hyperosmotic agent that usually used as part of a colorectal cleansing regiments. There is little information in the literature about its use for hypophosphatemia treatment.
CASE: We present the case of an 11-year-old child who was referred to the hospital with complaints of legs weakness. At the age of 3 years, he had complaints of slow growth and development, but he was still able to walk by himself. At the age of 6 years, he began to have walking difficulties and knock knee deformities. Since the age of 8 years, he gets tired and falls easily, and progressively become unable to walk. The patient has undergone laboratory tests which revealed recurrent hypopotassemia and hypophosphatemia, with normal plasma calcium and vitamin D level, elevated alkaline phosphatase. He then referred to pediatric nephrologist and endocrinologist. Bone survey was performed shows generalize osteoporosis with multiple fractures of bones, splaying and fraying metaphysis of the bones, compatible with rickets. There is no known family history with the same condition. The patient was then diagnosed as renal hypophosphatemic rickets and treated with oral sodium phosphate combined with potassium salt.
CONCLUSIONS: We conclude that oral sodium phosphate can provide clinical improvements such as physical activity and subjective complaints of patients with renal hypophosphatemic rickets, but its safety requires more observation.