Alendronate Treatment Regimen for Osteoporosis
The recommended treatment regimen for osteoporosis with alendronate is 70 mg once weekly or 10 mg once daily, taken with plain water at least 30 minutes before the first food, beverage, or medication of the day. 1
Patient Selection
- Treatment is recommended for patients with:
- T-score of -2.5 or less (osteoporosis)
- History of fragility fracture
- T-score between -1.0 and -2.5 (osteopenia) with 10-year risk of major osteoporotic fracture ≥20% or hip fracture ≥3% based on FRAX 2
Administration Instructions
- Take alendronate upon arising for the day
- Swallow with a full glass of water (6-8 oz)
- Remain upright (sitting or standing) for at least 30 minutes after taking
- Do not lie down until after consuming the first food of the day
- Do not take at bedtime or before arising for the day 1
- If a once-weekly dose is missed, take one dose on the morning after remembering, then return to the original weekly schedule 1
Supplementation During Treatment
- Calcium: 1000-1200 mg daily (diet and supplements)
- Vitamin D: 800 IU daily
- Take calcium supplements at a different time than alendronate to avoid interference with absorption 2, 1
Treatment Duration and Monitoring
- Initial treatment duration is typically 3-5 years
- Monitor bone mineral density (BMD) every 1-2 years to assess treatment response
- Consider stopping bisphosphonate treatment after 5 years, as increasing duration beyond this probably reduces vertebral fractures but increases risk of long-term adverse effects 2
- Decision to continue or discontinue should be based on:
- Baseline fracture risk
- Response to treatment
- Risk factors for future fractures
Efficacy
Alendronate has been demonstrated to:
- Increase bone mineral density at all skeletal sites
- Reduce the risk of vertebral fractures by 47-56% in postmenopausal women
- Reduce the risk of hip fractures in patients with osteoporosis 3, 4
- Increase BMD by 2.1-2.9% in the lumbar spine for patients on glucocorticoid therapy 5
Adverse Effects
- Common side effects: Upper GI irritation, abdominal pain, nausea, dyspepsia, acid regurgitation
- Rare but serious risks: Osteonecrosis of the jaw, atypical femoral fractures 2, 3
Alternative Formulations
Once-weekly dosing (70 mg) is therapeutically equivalent to daily dosing (10 mg) and offers improved convenience, which may enhance adherence 6
Special Considerations
- For patients with renal impairment, no dosage adjustment is needed if creatinine clearance is >35 mL/min
- For patients who cannot tolerate oral bisphosphonates or have concerns about absorption, consider alternative treatments such as zoledronic acid (IV) or denosumab (subcutaneous) 2, 7
- For patients at very high fracture risk, consider anabolic agents such as teriparatide 2
Common Pitfalls to Avoid
- Taking alendronate with food, beverages other than water, or medications decreases absorption
- Lying down within 30 minutes of taking alendronate increases risk of esophageal adverse effects
- Inadequate calcium and vitamin D supplementation may reduce treatment efficacy
- Abrupt discontinuation without transition to another antiresorptive agent may lead to rapid bone loss
Alendronate remains a first-line agent for osteoporosis treatment due to its efficacy, safety profile, extensive clinical experience, and availability of generic formulations 2.