Differences in persistence among different weekly oral bisphosphonate medications

Osteoporos Int. 2009 Aug;20(8):1369-76. doi: 10.1007/s00198-008-0795-8. Epub 2008 Nov 20.


Summary: We evaluated the differences in persistence with weekly oral bisphosphonate therapy according to the initial drug. Persistence to weekly oral preparations remains suboptimal, particularly in patients who receive generic alendronate. Alternative solutions are needed to improve the real life effectiveness of osteoporosis therapies.

Introduction: Poor persistence is widespread with oral osteoporosis (OP) therapy. The objective of this study was to evaluate the persistence among OP patients started on weekly oral bisphosphonates (BP).

Methods: Patients newly initiated on branded risedronate, branded alendronate, or generic alendronate once weekly were selected from the Régie de l'Assurance Maladie du Québec databases. The cohort included patients with and without a previous OP fracture. The probability and the risk factors for early discontinuation were estimated using Cox regression models.

Results: The study cohort included 32,804 patients. After 1 year, a significant difference in persistence on oral BP therapy was found. The patients started on branded risedronate were 11% more likely to stop OP therapy than patients started on branded alendronate. Risk of discontinuation doubled in patients initiated with generic alendronate compared to patients started on branded alendronate. Male gender was associated with a 25% increase risk of early discontinuation. No statistical association was found between previous OP fracture and early discontinuation.

Conclusion: This study provides further evidence of poor persistence to newly initiated oral weekly BP therapies, particularly for the patients started on generic alendronate.

MeSH terms

  • Administration, Oral
  • Aged
  • Aged, 80 and over
  • Alendronate / administration & dosage
  • Alendronate / therapeutic use
  • Bone Density Conservation Agents / administration & dosage*
  • Diphosphonates / administration & dosage*
  • Diphosphonates / therapeutic use
  • Drug Administration Schedule
  • Drugs, Generic / administration & dosage
  • Drugs, Generic / therapeutic use
  • Epidemiologic Methods
  • Etidronic Acid / administration & dosage
  • Etidronic Acid / analogs & derivatives
  • Etidronic Acid / therapeutic use
  • Female
  • Fractures, Bone / etiology
  • Fractures, Bone / prevention & control
  • Humans
  • Length of Stay
  • Male
  • Medication Adherence*
  • Middle Aged
  • Osteoporosis / complications
  • Osteoporosis / drug therapy*
  • Osteoporosis, Postmenopausal / complications
  • Osteoporosis, Postmenopausal / drug therapy
  • Patient Acceptance of Health Care / statistics & numerical data
  • Quebec
  • Risedronic Acid
  • Sex Factors


  • Bone Density Conservation Agents
  • Diphosphonates
  • Drugs, Generic
  • Risedronic Acid
  • Etidronic Acid
  • Alendronate