Bisphosphonates in the treatment of thalassemia-induced osteoporosis.

ABSTRACT

The aim of our randomized, placebo-controlled study was to investigate the effects of 2 years' daily oral administration of alendronate or intramuscular administration of clodronate every 10 days, on bone remodeling parameters and bone mineral density (BMD), safety and tolerability in a group of osteoporotic thalassemic patients. Twenty-five young patients (mean age 26.6 +/- 7.1 years) with beta-thalassemia major were randomly divided to receive placebo or 100 mg of clodronate intramuscularly every 10 days or 10 mg of alendronate per os daily. All patients took 500 mg of elemental calcium and 400 IU cholecalciferol in the evening at meal time. After 2 years, pyridinium crosslinks, which are bone resorption markers, did not differ significantly from baseline values in the placebo group, whereas they had decreased significantly in the clodronate and alendronate groups. Osteocalcin, a bone formation marker, did not change significantly in the placebo group, whereas it decreased slightly, but not significantly, in the clodronate and alendronate groups after 12 and 24 months. At the end of the study, the lumbar spine BMD had decreased significantly in the placebo group; it did not change significantly in the clodronate group; in the alendronate group it had increased but not significantly, whereas the increase was significant with respect to the placebo group. Femoral neck BMD decreased significantly in the placebo group; it did not change significantly in the clodronate group, but increased significantly in the alendronate group. No relevant side effects were recorded during our study. In conclusion, in patients with thalassemia-induced osteoporosis, the daily administration of alendronate significantly increases BMD, the most important predictor of the risk of fracture at several sites. Clodronate treatment at our dosage is ineffective in this pathology in spite of the good compliance of patients.