Purpose: To evaluate the changes in bone mineral density (BMD) after alendronate intake and to determine the side effects and patient compliance.
Materials and Methods: 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.
Results: 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 L-spine and femur, respectively, and the BMD changes in patients with a T-score > -3.0 were 2.5% and 3.1% for the L-spine and femur, respectively. The reasons for early discontinuation of alendronate were difficulty in intake, economic reasons, and adverse events.
Conclusion: 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 L-spine, 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%.

Keywords: Osteoporosis, Alendronate, Bone mineral density (BMD), Early discontinuation, Adverse event