Alendronate is more effective than etidronate for increasing bone mass in osteopenic patients with primary biliary...

Osteopenia increases the morbidity of primary biliary cirrhosis (PBC). In this study, we have compared two bisphosphonates, alendronate and cyclical etidronate, that inhibit osteoclast-mediated bone resorption and have examined their effects on bone mass in patients with this disease.

A total of 32 women with PBC were randomly assigned to receive alendronate (10 mg/day) or etidronate (400 mg/day) for 14 days every 3 months. Bone mineral density of the lumbar spine and proximal femur were measured initially and every 6 months. Bone fractures and markers of bone mineral metabolism were also evaluated.

Sixteen patients were allocated to each group, which were comparable with respect to the severity of PBC and osteopenia. Thirteen patients in each group completed the 2-yr trial. Both treatments increased bone mineral density after 2 yr, although the increase at the lumbar spine and at the proximal femur was significantly higher in patients receiving alendronate than in patients on etidronate. This higher effect of alendronate paralleled with changes in the biochemical markers of bone turnover. No patient developed new vertebral fractures, but new peripheral fractures were detected in two patients on alendronate and in one on etidronate. There were no serious adverse effects. Neither treatment impaired liver function or cholestasis.

Alendronate effectively increases bone mass and has greater antiresorptive power than etidronate in patients with primary biliary cirrhosis, and is associated with minor or no side effects.