To assess the effects of 3-amino-1-hydroxypropylidine-1,1-bisphosphonate (pamidronate) in rheumatoid arthritis (RA).
Thirty patients with active RA were randomly allocated to receive a single intravenous infusion of placebo, 20 mg pamidronate, or 40 mg pamidronate.
Pamidronate treatment resulted in a rapid and sustained reduction in urinary calcium and hydroxyproline excretions. A sustained reduction in serum corrected calcium was only noted in the group treated with 40 mg pamidronate. In both groups treated with pamidronate a temporary increase in serum parathyroid hormone was noted. Compared to the placebo group clinical variables of disease activity improved significantly in both groups treated with aminohydroxypropylidine bisphosphonate. The erythrocyte sedimentation rate and serum C-reactive protein levels improved significantly in patients treated with 40 mg pamidronate. No serious side effects were documented.
A single infusion of pamidronate in patients with RA is safe, suppresses bone resorption, and reduces disease activity. It is suggested that the effect on disease activity is dose dependent.