• Convenience of monthly Bonviva over weekly risedronate [ Time Frame: 6 months ] [ Designated as safety issue: No ]
• Change in serum CTX [ Time Frame: 12 weeks/3 months ] [ Designated as safety issue: No ]
• Upper gastrointestinal symptoms [ Time Frame: 12 weeks/3 months ] [ Designated as safety issue: No ]
• AEs and laboratory parameters [ Time Frame: Throughout study ] [ Designated as safety issue: No ]

This 2 arm crossover study will evaluate patient reported preference for either once monthly Boniva (150mg p.o.) or once weekly risedronate (35mg p.o.). Patients with post-menopausal osteoporosis will be randomized to receive Boniva for 3 calendar months or risedronate for 12 weeks; they will then cross over to receive the alternative treatment for a further 12 weeks/3 months. The anticipated time on study treatment is 3-12 months, and the target sample size is 100-500 individuals.

• Drug: ibandronate [Bonviva/Boniva]
• Drug: Risedronate

Inclusion Criteria:

• ambulatory women with post-menopausal osteoporosis;
• patients who are bisphosphonate-naive, or who have previously received oral daily or i.v. bisphosphonate therapy (fulfilling certain criteria detailed in the protocol).

Exclusion Criteria:

• malignant disease diagnosed within previous 10 years (except for successfully resected basal cell cancer;) breast cancer within previous 20 years;
• inability to stand or sit upright for at least 60 minutes;
• disease/disorder/treatment with drugs known to influence bone metabolism.