Alendronate sodium trihydrate is primarily used in the treatment and prevention of osteoporosis, particularly in postmenopausal women and men. It helps to increase bone mass and reduce the risk of fractures by inhibiting bone resorption. This medication is also effective in managing glucocorticoid-induced osteoporosis and Paget's disease of bone. It is typically administered orally in tablet form and works by binding to hydroxyapatite in bone tissue, thereby slowing down the activity of osteoclasts. Patients are advised to take it with water on an empty stomach and remain upright for at least 30 minutes to minimize gastrointestinal side effects. Regular monitoring of bone density is often recommended to assess treatment efficacy.