To investigate the efficacy and tolerability of intravenous clodronate in patients with rheumatoid arthritis (RA).
Twenty-six patients with active RA were randomly allocated to receive either a single iv. infusion of placebo or 600 mg clodronate. Efficacy and safety were assessed weekly during the following three weeks by clinical and laboratory evaluations.
Serum osteocalcin and carboxyterminal propeptide of type I procollagen (markers of bone metabolism) were significantly decreased in the clodronate group at the end of the study, whereas the indices of disease activity including number of swollen joints, number of tender joints, patient's and doctor's estimation of condition (visual analogue scale), erythrocyte sedimentation rate and serum C-reactive protein level were not affected by clodronate treatment. No serious adverse effects were observed.
A single infusion of clodronate in patients with RA was safe and caused a decline in the markers of bone metabolism, but this short-term treatment did not suppress disease activity. Results from recent clinical and preclinical studies, however, suggest that the anti-inflammatory efficacy of clodronate requires liposome encapsulation.