What are examples of bisphosphonates (BPs) used to treat osteoporosis?

Examples of Bisphosphonates Used to Treat Osteoporosis

The main bisphosphonates used to treat osteoporosis include alendronate, risedronate, ibandronate, and zoledronic acid, with oral bisphosphonates (alendronate and risedronate) recommended as first-line treatment options. 1

First-Line Oral Bisphosphonates

• Alendronate

  • Dosing: 70mg weekly or 10mg daily 1
  • First FDA-approved bisphosphonate for osteoporosis 2
  • Proven efficacy in increasing bone mineral density and reducing fracture risk 2

• Risedronate

  • Dosing: 35mg weekly 3
  • Effectively prevents bone loss associated with aromatase inhibitors in postmenopausal women 3
  • Well-studied for efficacy and safety in osteoporosis 4

Second-Line Intravenous Bisphosphonates

• Zoledronic acid

  • Dosing: 4mg IV every 6 months or 5mg yearly 3, 1
  • Most potent bisphosphonate available 3
  • Particularly effective in preventing bone loss in premenopausal women on ovarian suppression 3
  • Common side effects include transient flu-like symptoms after infusion 1

• Ibandronate

  • Dosing: 150mg oral monthly or intravenous formulation 3, 5
  • FDA-approved for treatment of postmenopausal osteoporosis 5
  • Optimal duration of use not determined; consider discontinuation after 3-5 years in low-risk patients 5

Other Bisphosphonates

• Pamidronate

  • Administered intravenously 4
  • Used off-label when approved agents cannot be tolerated 4
  • Requires 2-4 hour infusion time 3

• Clodronate

  • Available in oral (1600mg daily) and IV forms 3
  • Not approved in many EU countries 3
  • Has shown efficacy in preventing bone loss in postmenopausal women 3

• Etidronate

  • First bisphosphonate described 6
  • Less potent than newer agents 3
  • Can be used off-label for patients who cannot tolerate approved agents 4

Relative Potency

The relative potency of bisphosphonates in inhibiting bone resorption follows this order (from least to most potent): Etidronate < Clodronate < Pamidronate < Alendronate < Risedronate < Ibandronate < Zoledronic acid 3

Important Considerations

• Administration requirements: Oral bisphosphonates must be taken with at least 6 oz of water, 30 minutes before food or other beverages 2

• Contraindications: Oral bisphosphonates should be avoided in patients with esophageal emptying disorders or those who cannot sit upright due to risk of pill esophagitis 3

• Renal considerations: IV bisphosphonates generally not recommended in patients with creatinine clearance <30 mL/min 3

• Potential adverse effects:

  • Osteonecrosis of the jaw (rare)
  • Atypical femur fractures (rare)
  • GI disturbances with oral formulations
  • Acute phase reactions with IV formulations 1, 7

• Duration of therapy: Consider drug discontinuation after 3-5 years in low-risk patients 5

• Supplementation: Always ensure adequate calcium (1000-1200 mg/day) and vitamin D (800 IU/day) intake when starting bisphosphonate therapy 1

Bisphosphonates remain the cornerstone of osteoporosis treatment, with proven efficacy in preventing fractures and increasing bone mineral density. The choice between different bisphosphonates should be based on patient factors, administration preferences, and specific clinical scenarios.