What is the recommended treatment regimen for osteoporosis using Fosamax (alendronate)?

Fosamax (Alendronate) Treatment Regimen for Osteoporosis

For postmenopausal women with osteoporosis, the recommended regimen is alendronate 70 mg once weekly or 10 mg once daily, with the once-weekly formulation being strongly preferred due to superior patient adherence and convenience. 1

Dosing Regimens by Indication

Treatment of Postmenopausal Osteoporosis

• 70 mg tablet once weekly (preferred) 1
• Alternative: 10 mg tablet once daily 1
• The once-weekly regimen is therapeutically equivalent to daily dosing and demonstrates 86.4% patient preference over daily administration 2

Prevention of Osteoporosis in Postmenopausal Women

• 35 mg tablet once weekly 1
• Alternative: 5 mg tablet once daily 1

Treatment in Men with Osteoporosis

• 70 mg tablet once weekly 1
• Alternative: 10 mg tablet once daily 1

Glucocorticoid-Induced Osteoporosis

• 5 mg tablet once daily for most patients 1
• 10 mg tablet once daily for postmenopausal women not receiving estrogen 1
• Oral bisphosphonates are strongly recommended over no treatment in high and very high fracture risk 3

Critical Administration Instructions

Proper administration is essential to maximize efficacy and minimize esophageal complications: 1

• Take at least 30 minutes before the first food, beverage, or medication of the day 1
• Use plain water only (6-8 ounces) - other beverages reduce absorption 1
• Swallow tablet whole; do not crush or chew 1
• Remain upright (standing or sitting) for at least 30 minutes after taking 1
• Take upon arising for the day - never at bedtime 1
• Wait for first food of the day before lying down 1

Essential Calcium and Vitamin D Supplementation

All patients on alendronate require adequate calcium and vitamin D supplementation: 3

• Calcium: 1,000-1,200 mg daily (total from diet and supplements) 3
• Vitamin D: 800-1,000 IU daily 3
• Consider higher vitamin D doses (≥800 IU) as 47% of patients on 400 IU daily fail to achieve optimal 25-hydroxyvitamin D levels 4
• Monitor serum 25-hydroxyvitamin D levels, targeting ≥30 ng/mL 3
• Patients with vitamin D deficiency should be repleted before starting bisphosphonates to prevent hypocalcemia 3

Duration of Therapy

Treatment duration typically ranges from 3-5 years, with consideration for interruption after 5-10 years: 3

• Continue longer in patients who remain at high fracture risk 3
• Reassess fracture risk periodically during treatment 3
• Monitor bone mineral density (BMD) every 1-2 years during therapy 3

Contraindications and Precautions

Absolute contraindications include: 3, 1

• Esophageal abnormalities that delay esophageal emptying 3, 1
• Inability to stand or sit upright for at least 30 minutes 3, 1
• Hypocalcemia (must be corrected before treatment) 3, 1
• Hypersensitivity to alendronate 3, 1

Use with caution in: 3

• Creatinine clearance <35 mL/min (consider alternative agents) 3
• Patients at risk for aspiration (avoid oral solution) 3
• Active upper GI disorders 1

Efficacy Evidence

Alendronate demonstrates robust fracture reduction: 3, 5

• 47-56% reduction in vertebral fractures in postmenopausal women with existing fractures 5
• Reduces vertebral, non-vertebral, and hip fractures in high-risk patients 3
• Produces sustained increases in BMD at spine and hip 5, 6
• Once-weekly 70 mg formulation is therapeutically equivalent to daily 10 mg 6, 2

Monitoring and Follow-Up

Systematic monitoring improves adherence and outcomes: 3

• BMD with vertebral fracture assessment every 1-2 years 3
• Serum 25-hydroxyvitamin D levels periodically 4
• Assess adherence at each visit (adherence >95% in structured programs) 3
• If BMD loss occurs during treatment, verify patient adherence to administration instructions 3

Common Pitfalls to Avoid

Improper administration is the most common cause of treatment failure and adverse events: 1

• Taking with food, coffee, or juice instead of plain water reduces absorption significantly 1
• Lying down within 30 minutes increases esophageal irritation risk 1
• Inadequate vitamin D supplementation (400 IU often insufficient) 4
• Poor long-term adherence without structured follow-up 3

Missed Dose Instructions

If a once-weekly dose is missed: 1

• Take one dose the morning after remembering 1
• Do not take two doses on the same day 1
• Return to the original once-weekly schedule 1