Overcoming resistance to bisphosphonates through the administration of alfacalcidol: results of a 1-year, open follow-up study

János Gaál (1) , Tamás Bender (2) , József Varga (3) , Irén Horváth (1) , Judit Kiss (1) , Péter Somogyi (4) , Péter Surányi (1)

1 Department of Rheumatology and Physical Therapy
2 Polyclinic of the Hospitaller Brothers of St. John of God in Buda
3 Department of Nuclear Medicine
4 Department of Orthopaedics, Faculty of Medicine

This study intended to determine whether the replacement of vitamin D3 with alfacalcidol results in any bone mineral density (BMD) increase in 76 patients unresponsive to the combination of alendronate and conventional vitamin D3 treatment. In these patients the conventional vitamin D3 had been replaced with alfacalcidol (0.5 μg/day), and then the patients were followed up for a year. After treatment for 1 year, Wilcoxon test revealed a small but statistically significant ( < 0.001) increase in the BMD values of the forearm and lumbar vertebrae, in the serum calcium and urinary calcium/creatinine ratio in first-voided morning urine. However, the serum alkaline phosphatase activity, phosphorus, parathormone, osteocalcin levels and the urinary -pyr/creatinine ratio decreased significantly ( < 0.001). As suggested by our results, combination therapy with alendronate and alfacalcidol increases bone density and improves the biochemical markers of bone turnover, without any substantial increase in the incidence of adverse effects.

Mots clés: Osteoporosis; Resistance to bisphosphonates; Alfacalcidol

János Gaál, Tamás Bender, József Varga, Irén Horváth, Judit Kiss, et al.. Overcoming resistance to bisphosphonates through the administration of alfacalcidol: results of a 1-year, open follow-up study. Rheumatology International, 2009, 30 (1), pp.25-31. ⟨10.1007/s00296-009-0892-9⟩. ⟨hal-00568281⟩