Fosamax Actonel Comparison Trial

Introduction

Comparison:

• once-weekly alendronate 70 mg compared with
• once-weekly risedronate 35 mg in women with postmenopausal osteoporosis

Design:

• randomized, double-blind trial conducted at 78 sites in the USA
• postmenopausal women
  • 40 years of age or older
  • over 25 years of age if surgically menopausal
  • low bone density*
• 1,042 patients

* defined as a BMD of >= -2.0 SD below young adult mean BMD in at least one site (total hip, hip trochanter, femoral neck, or PA lumbar spine)

Exclusion criteria:

• history of esophageal abnormalities
• those unable to remain upright for at least 30 minutes after dosing
• low concentrations of vitamin D
• metabolic bone disease
• use of systemic estrogen, estrogen analogues, tibolone, or anabolic steroids within the past 6 months
• use of bisphosphonates or parathyroid hormone within the past 12 months
• daily prednisone 7.5 mg > 1 month in the last 6 months
• use of immunosupressants

Patients were treated for 12 months*

• both the patient & investigators were blinded

* an additional 12 months where only the patients were blinded (not yet been reported)

Outcomes:

• BMD at the hip trochanter dual energy X-ray absorptiometry (DEXA) at 0 6, & 12 months
• other BMD assessments included posterior-anterior (PA) lumbar spine proximal femur
• urinary N-telopeptide of type I human collagen
• serum bone-specific alkaline phosphatase
• serum N terminal propeptide of type 1 procollagen

Results:

• alendronate increased bone density of the hip by 3.4% in one year compared with 2.1% for risedronate
• differences also favored alendronate at lumbar spine
• reduction in bone turnover (all biochemical markers) greater with alendronate than risedronate at 3-12 months
• adverse effects was similar in the 2 groups
  • upper GI effects in 20-22%

More general terms

• clinical trial