What is the recommended duration of treatment with Fosamax (alendronate) for patients with osteoporosis?

Duration of Alendronate (Fosamax) Treatment for Osteoporosis

The recommended duration of treatment with Fosamax (alendronate) for osteoporosis is 5 years, after which treatment continuation should be reassessed based on fracture risk. 1

Treatment Duration Guidelines

The American College of Physicians provides clear guidance on bisphosphonate treatment duration:

• Initial treatment period: 5 years 1
• After 5 years, patients should be reassessed for:
  • Fracture risk
  • Bone mineral density (BMD) stability
  • Occurrence of fractures during treatment

Treatment Continuation vs. Drug Holiday Algorithm

Consider discontinuation (drug holiday) after 5 years if:

• Patient has stable or improved BMD
• No fractures during treatment
• Low fracture risk 2
• T-score > -2.5

Consider continuing beyond 5 years if:

• High risk of clinical vertebral fractures 3
• T-score remains ≤ -2.5, especially at hip sites
• Fractures occurred during initial treatment period
• Very high baseline fracture risk

Monitoring During and After Treatment

• BMD monitoring during the 5-year treatment period is not recommended 1
• After stopping treatment, BMD should be reassessed in 1-2 years 4
• Bone turnover markers may gradually rise after discontinuation but typically remain below pretreatment levels 3

Rationale for Limited Treatment Duration

• Bisphosphonates accumulate in bone and continue to be released for months to years after discontinuation 2
• The FLEX trial showed that women who discontinued alendronate after 5 years had:
  • Only moderate declines in BMD
  • Gradual increases in bone turnover markers
  • No significant increase in nonvertebral fracture risk compared to those who continued treatment 3
  • However, clinical vertebral fractures were 55% higher in those who discontinued 3

Important Considerations

• The FDA label for alendronate states: "The optimal duration of use has not been determined" 5
• Patients at low risk for fracture should be considered for drug discontinuation after 3-5 years 5
• Long-term bisphosphonate use is associated with rare but serious adverse effects:
  • Osteonecrosis of the jaw
  • Atypical femoral fractures
  • Esophageal irritation (with oral administration) 2

Special Populations

For patients with breast cancer on adjuvant therapy:

• Duration should not exceed 3-5 years unless indicated for low T-score 1
• For postmenopausal women at intermediate/high recurrence risk, bisphosphonate treatment should be 3-5 years 1

Remember that the decision to continue or discontinue alendronate after 5 years should be based on a careful assessment of individual fracture risk factors, with continuation generally recommended for those at highest risk of vertebral fractures.