To evaluate the changes in bone mineral density (BMD) after alendronate intake and to determine the side effects and patient compliance.

Two hundred twelve patients with osteoporosis were treated with alendronate. One hundred sixty-two patients were excluded because of early discontinuation. Thus, 50 patients were included in the analysis.

The annual increase in BMD in patients taking alendronate was 7.2% (1st year), 3.4%, 2.0%, and 0.9% (4th year) in the L-spine, and 2.2%, 1.5%, -0.9%, and 0.9% in the femur. The changes in BMD of patients< 60 years of age were 2.1% in the L-spine and 3.4% in the femur. The BMD of patients between 60 and 69 years of age increased 6.3% and 0.5% in the L-spine and femur, respectively, and the BMD of patients >70 of age were 2.9% and 1.2% in the L-spine and femur, respectively. The BMD changes in patients with a T-score< -4.0 were 7.0% (L-spine) and 1.2% (femur), the BMD changes in patients with a T-score between -3.0 and -3.9 were 5.3% and 0.2% for the Lspine and femur, respectively, and the BMD changes in patients with a T-score >3.0 were 2.5% and 3.1% for the Lspine and femur, respectively. The reasons for early discontinuation of alendronate were difficulty in intake, economic reasons, and adverse events.

The BMD changes were greater in the L-spine than the femu in alendronate users. At the first year, the changes in BMD was greatest. There was no significant difference in BMD change according to age. In the Lspine, however, BMD changes were greater in the group with lower T-scores. The early discontinuance rate was 74%, and the adverse events rate was 19.8%.