Osteomalacia in a patient with Paget's bone disease treated with long-term etidronate
Service de rhumatologie, CHU, 49933 Angers cedex, FranceMorphologie 09/2012; 96(313):40-3. DOI: 10.1016/j.morpho.2012.08.001
A 93 year-old woman with Paget's disease of bone had been treated with etidronate without interruption during 20years. The daily dose was usual (5mg/kg/day) but this prescription had never been stopped by her physicians. Two fractures had already occurred in pagetic (right tibia) and non pagetic bones (right fibula) within the last 2years, and she presented rib fractures, another right tibia fracture and right femur fracture during hospitalization time. X-rays films showed major osteolysis of left ulna and right tibia. Blood samples and technetium bone scan brought no evidence for sarcoma or lytic evolution of the disease. A transiliac bone biopsy on non pagetic bone site confirmed the diagnosis of osteomalacia (increased osteoid parameters), with secondary hyperparathyroidism (hook resorption). In Paget's disease of bone, continuous treatment by etidronate may induce generalized osteomalacia, and increase the risk of fracture in both pagetic and non-pagetic bones. Whereas physicians and pharmaceutical industry try to improve the observance of those drugs, this striking observation also points out that a prescription always needs to be updated.
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ABSTRACT: Background: generalised proximal, type 2, Renal Tubular Acidosis, also known as Fanconi syndrome, is a generalised dysfunction of the proximal renal tubule characterized by impaired reabsorption and increased urinary loss of phosphate and other solutes such as uric acid, glucose, amino acids and bicarbonate. Chronic hypophosphatemia is the second most common cause of osteomalacia after vitamin D deficiency in adult patients. It can have a heterogeneous presentation ranging from mild symptoms such as muscle weakness and skeletal pain to more severe presentation such as disabling myopathy, severe bone and joint pain, difficult walking, and even bone fractures.Objective: this report describes a case of severe hypophosphatemic osteomalacia with multiple fragility fractures induced by adefovir, which was worsened and confounded by a previous treatment with zoledronic acid and required prolonged i.v. potassium phosphate administration. Results and conclusions: we highlight the limited diagnostic value of DXA and bone scintigraphy in this challenging diagnosis. Bone metabolism should be always assessed in patients treated with adefovir for early detection of osteomalacia due to Fanconi Syndrome. Although rare, this condition may be life-threatening and mimic other bone metabolic disorders that are treated with drugs which may further impair phosphate balance.Endocrine Practice 08/2014; 1(-1):1-15. DOI:10.4158/EP14251.CR · 2.81 Impact Factor
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