When is alendronate (bisphosphonate) indicated for osteoporosis treatment?

Indications for Alendronate in Osteoporosis Treatment

Alendronate is indicated as first-line therapy for patients with osteoporosis (T-score ≤-2.5) or those with high fracture risk, including postmenopausal women, men with osteoporosis, and patients with glucocorticoid-induced osteoporosis. 1, 2

Primary Indications Based on Fracture Risk

Definite Indications:

• T-score of -2.5 or less (osteoporosis by DEXA) 1
• History of low-trauma fracture, even if DEXA does not indicate osteoporosis 1
• 10-year risk of major osteoporotic fracture ≥20% or hip fracture risk ≥3% by FRAX 1, 3

Special Populations:

• Postmenopausal women with osteoporosis 2
• Men with osteoporosis 2
• Patients receiving glucocorticoids in a daily dosage equivalent to 7.5 mg or greater of prednisone who have low BMD 2
• Cancer survivors with treatment-related bone loss, including: 1
  • Premenopausal women receiving GnRH therapies causing ovarian suppression
  • Women with chemotherapy-induced ovarian failure
  • Postmenopausal women receiving aromatase inhibitors
  • Men receiving androgen deprivation therapy

Dosing Options

• Treatment: 10 mg daily or 70 mg weekly 2, 4
• Prevention: 5 mg daily or 35 mg weekly 2
• For osteoporosis with vitamin D deficiency: Alendronate/cholecalciferol (70 mg plus 2,800 IU or 5,600 IU weekly) 1

Efficacy Profile

• Reduces clinical vertebral fractures by 44-56% in both primary and secondary prevention 5, 6
• Reduces non-vertebral fractures by 17-20% 5
• Reduces hip fractures by 24-51%, with greater benefit in secondary prevention 5
• Increases bone mineral density at all skeletal sites 7, 6

Administration Considerations

• Must be taken with at least 6-8 oz of plain water
• Must be taken at least 30 minutes before first food, beverage, or medication of the day
• Patient must remain upright (sitting or standing) for at least 30 minutes after taking 2, 8
• Weekly dosing (70 mg) provides equivalent efficacy to daily dosing with improved convenience and potentially better adherence 4

Treatment Duration and Monitoring

• After 5 years of therapy, clinicians should consider a drug holiday unless there is a strong indication for continued treatment 1, 3
• Bone mineral density should be monitored every 2 years 3
• Fracture risk should be reassessed every 1-2 years 3

Contraindications

• Abnormalities of the esophagus that delay esophageal emptying
• Inability to stand or sit upright for at least 30 minutes
• Hypocalcemia
• Hypersensitivity to alendronate
• Severe renal impairment (creatinine clearance <35 mL/min) 1, 2

Important Considerations

• Adequate calcium (1,000-1,200 mg/day) and vitamin D (600-800 IU/day) supplementation should accompany alendronate therapy 3
• Lifestyle modifications including weight-bearing exercise, smoking cessation, and limiting alcohol intake should be recommended alongside medication 1, 3
• Rare but serious adverse effects include osteonecrosis of the jaw and atypical femoral fractures, particularly with long-term use 3, 5
• For very high-risk patients (prior fracture, T-score ≤-3.5, FRAX ≥30% for major osteoporotic fracture), anabolic agents may be preferred over bisphosphonates 3

Alendronate remains a cornerstone of osteoporosis treatment due to its established efficacy, safety profile, and cost-effectiveness as a generic medication 1, 7.