Overview
Alendronate is a bisphosphonate medication used to treat and prevent osteoporosis in postmenopausal women and men, as well as glucocorticoid-induced osteoporosis and Paget's disease of bone. It works by inhibiting osteoclast-mediated bone resorption, thereby increasing bone mineral density and reducing fracture risk. Proper administration requires taking the medication with plain water on an empty stomach and remaining upright for at least 30 minutes to minimize esophageal irritation.
Mechanism of Action
Alendronate is a bisphosphonate that binds to bone hydroxyapatite and specifically inhibits osteoclast activity, reducing bone resorption. It has no direct effect on bone formation, but bone formation decreases secondarily due to the coupling of bone resorption and formation during bone turnover.
Indications
- Treatment of osteoporosis in postmenopausal women
- Treatment of osteoporosis in men
- Treatment and prevention of glucocorticoid-induced osteoporosis
- Treatment of Paget's disease of bone
Common Doses
- 5 mg
- 10 mg
- 35 mg
- 40 mg
- 70 mg
Dosage
For osteoporosis treatment: 10 mg once daily or 70 mg once weekly. For osteoporosis prevention: 5 mg once daily or 35 mg once weekly. For Paget's disease: 40 mg once daily for 6 months. Must be taken with plain water at least 30 minutes before the first food, beverage, or medication of the day, and patients must remain upright for at least 30 minutes after administration.
Contraindications
- Abnormalities of the esophagus which delay esophageal emptying (stricture or achalasia)
- Inability to stand or sit upright for at least 30 minutes
- Hypocalcemia
- Hypersensitivity to any component of the product
Side Effects
- Upper gastrointestinal adverse reactions (dysphagia, esophagitis, esophageal ulcers)
- Musculoskeletal pain (bone, joint, muscle pain)
- Hypocalcemia
- Hypophosphatemia
- Osteonecrosis of the jaw
- Atypical femoral fractures
- Hypersensitivity reactions (urticaria, angioedema)
Interactions
- Calcium supplements, antacids, and other medications containing polyvalent cations (iron, magnesium, aluminum) should be taken at a different time of day as they can interfere with absorption
- NSAIDs may increase risk of gastrointestinal irritation
Counseling Points
- Take with 6-8 ounces of plain water only (not mineral water, coffee, tea, juice, or other beverages)
- Take at least 30 minutes before the first food, beverage, or other medication of the day
- Remain upright (sitting or standing) for at least 30 minutes after taking the medication
- Do not lie down until after eating the first food of the day
- Report any new or unusual thigh, hip, or groin pain
- Report any difficulty swallowing, pain when swallowing, chest pain, or new or worsening heartburn
- Maintain adequate calcium and vitamin D intake as recommended by your healthcare provider
- Attend regular dental checkups and inform your dentist you are taking this medication