[Treatment of Paget's osteitis deformans].

Specific treatment of osteitis deformans (OD, Paget's disease of bone) is indicated when symptoms are associated with signs (biochemical or by bone scintigraphy) of active disease. OD in the base of the skull and osteolytic lesions in weight-bearing bones should be treated irrespective of symptoms. The effect of calcitonin (CT) on symptoms and skeletal blood-flow is achieved rapidly and healing of osteolytic lesions may occur. However, CT is only effective in approximately 60%, is discontinued due to side effect in 20% of patients, and must be administered parenterally. EHDP (Etidronate) is administered orally but the use of even small doses carries a risk of mineralisation defect and possibly fracture. EHDP should, therefore, be given intermittently and should not be used in osteolytic lesions of weight-bearing bones. Second-generation bisfofonates are devoid of this side effect and are very effective in OD. The effect of mithramycin is only transient and because of the risk of serious side effects the use should be restricted to severe cases of OD resistant to the other lines of treatment.