Effects of Aminobisphosphonate Infusion on Biochemical Indices of Bone Metabolism in Rheumatoid Arthritis

In a phase 1 study, seven patients with classical rheumatoid arthritis were treated with intravenous 3-amino-1-hydroxypropylidene-1-1-bisphosphonate (APD). Following this treatment, bone resorption as measured by fasting urine calcium/creatinine and hydroxyproline/creatinine ratios, was reduced. This was sustained for 6 months in only three patients. Elevations of these ratios often coincided with flares of active arthritis in the remaining four patients. Bone turnover as measured by serum osteocalcin levels was reduced in all patients but serum alkaline phosphatase levels remained unchanged. There was no consistent improvement in clinical indices of disease activity.