Does Fosamax (alendronate) strengthen bones?

Fosamax (Alendronate) Does Strengthen Bones

Yes, Fosamax (alendronate) effectively strengthens bones by increasing bone mineral density and reducing fracture risk. 1

Mechanism of Action

• Alendronate is a bisphosphonate that binds to bone hydroxyapatite and specifically inhibits the activity of osteoclasts (bone-resorbing cells) 1
• It shows preferential localization to sites of bone resorption, specifically under osteoclasts, inhibiting their activity without interfering with their recruitment or attachment 1
• Alendronate reduces bone turnover (the number of sites at which bone is remodeled) while allowing bone formation to exceed bone resorption, leading to progressive gains in bone mass 1

Evidence of Bone Strengthening

Bone Mineral Density (BMD) Improvements

• Clinical trials demonstrate that alendronate produces sustained increases in BMD in the following areas:

  • Lumbar spine: 5.1-5.4% increase after one year of treatment 1
  • Hip and femoral neck: Significant increases compared to placebo 1
  • Trochanter: Progressive gains maintained during treatment 1

• These BMD improvements are evident as early as three months and continue throughout treatment 1

Fracture Risk Reduction

• Alendronate reduces the risk of:

  • Vertebral fractures by 47-56% in postmenopausal women 2
  • Hip fractures by approximately 50% 2, 3
  • All clinical fractures by about 30% 3

• The Fracture Intervention Trial demonstrated that 3 years of treatment with alendronate reduces all clinically relevant fractures, including hip fractures 3

Dosing Options

• Treatment of osteoporosis: 70 mg once weekly (often combined with vitamin D as Fosamax Plus D) 4
• Prevention of osteoporosis: 35 mg once weekly or 5 mg daily 4
• Once-weekly dosing (70 mg) is therapeutically equivalent to daily dosing (10 mg) and offers greater convenience 5

Bone Quality

• Histomorphometric analyses have found that alendronate does not impair bone quality 2
• Bone histology in 270 postmenopausal patients with osteoporosis treated with alendronate revealed normal mineralization and structure 1
• The bone formed during therapy with alendronate is of normal quality 1

Important Considerations and Precautions

• Alendronate must be taken properly to maximize effectiveness and minimize side effects:

  • Take on an empty stomach with a full glass of water 6
  • Remain upright (sitting or standing) for at least 30 minutes after taking 6
  • Do not eat or drink anything for at least 30 minutes after taking 6

• Common side effects include:

  • Upper gastrointestinal issues (abdominal pain, dyspepsia, acid regurgitation) 2
  • Musculoskeletal pain 2

• Rare but serious side effects:

  • Esophageal ulceration (usually associated with improper administration) 7
  • Osteonecrosis of the jaw (very rare, <1 case per 100,000 person-years) 6
  • Atypical femur fractures with long-term use 6

• Contraindicated in patients with:

  • Abnormalities of the esophagus that delay emptying
  • Inability to stand or sit upright for at least 30 minutes
  • Hypocalcemia
  • Hypersensitivity to any component of the product 4
  • Chronic kidney disease with GFR < 35 ml/min/1.73 m² 4

Duration of Treatment

• The optimal duration of bisphosphonate therapy is not definitively established, but there appears to be a trend toward interrupting therapy after five to ten years due to concerns about rare adverse effects with long-term use 4
• Some experts recommend discontinuation after 5 years with careful observation due to the prolonged effects of bisphosphonates and uncertainty about their long-term safety 6

In conclusion, Fosamax (alendronate) is a well-established treatment that effectively strengthens bones by increasing bone mineral density and reducing fracture risk when taken as prescribed.