When should Fosamax (alendronate) be initiated in patients with osteoporosis?

When to Start Fosamax (Alendronate)

Alendronate should be initiated in patients with a BMD T-score of less than -2.0 or in those with a T-score above -2.0 who have at least two clinical risk factors for fracture. 1

Indications for Starting Alendronate

Based on Bone Mineral Density (BMD)

• Start alendronate in patients with a BMD T-score less than -2.0 1
• Consider alendronate in patients with osteopenia (T-score between -1.0 and -2.5) who have additional risk factors 1

Based on Risk Factors

• Initiate treatment in patients with two or more of the following risk factors, even if T-score is above -2.0: 1
  • Age over 65 years
  • Current smoking or history of smoking
  • Low BMI (<24)
  • Family history of hip fracture
  • Personal history of fragility fracture after age 50
  • Oral glucocorticoid use for more than 6 months

Special Populations

• In cancer patients receiving endocrine treatment (aromatase inhibitors for breast cancer or androgen deprivation therapy for prostate cancer), start alendronate if T-score is less than -2.0 or if patient has two or more risk factors 1
• For patients on glucocorticoid therapy, consider alendronate to prevent bone loss 1

Dosing Recommendations

• For treatment of osteoporosis: 70 mg once weekly (preferred dosing regimen) 2, 3
• For prevention of osteoporosis: 35 mg once weekly or 5 mg daily 2
• Consider combination with vitamin D (Fosamax Plus D: 70 mg alendronate plus 2,800 IU or 5,600 IU vitamin D) for patients with or at risk for vitamin D deficiency 2

Monitoring and Follow-up

• Measure BMD at baseline and repeat after 1-2 years of treatment to assess response 1
• For patients with osteopenia (T-score > -2.0), BMD measurements do not need to be repeated routinely unless baseline T-score is < -2.0 or new risk factors develop 1
• Consider shorter monitoring intervals (1 year) after initiation of therapy or in high-risk patients such as those on glucocorticoid therapy 1

Duration of Therapy

• The optimal duration of bisphosphonate therapy is not definitively established, but consider interrupting therapy after 5-10 years due to concerns about rare adverse effects with long-term use 2

Contraindications and Precautions

• Do not use alendronate in patients with:
  • Abnormalities of the esophagus that delay esophageal emptying 2
  • Inability to stand or sit upright for at least 30 minutes 2, 3
  • Hypocalcemia 2
  • Chronic kidney disease with GFR < 35 ml/min/1.73 m² 2
  • Hypersensitivity to any component of the product 2
• Correct vitamin D deficiency before initiating alendronate, particularly before intravenous bisphosphonate therapy, as vitamin D deficiency may attenuate efficacy and increase risk of hypocalcemia 1

Clinical Pearls and Pitfalls

• Alendronate is considered first-line therapy for osteoporosis treatment due to its established efficacy in reducing fracture risk 2, 4
• Patients must take oral alendronate with a full glass of water at least 30 minutes before consuming food or beverages to ensure proper absorption 3
• Instruct patients to remain upright for at least 30 minutes after taking alendronate to reduce risk of esophageal irritation 1
• Consider dental evaluation before starting therapy, as osteonecrosis of the jaw is a rare but serious complication, particularly in patients requiring dental surgery 1