Comparison of the Effect of an Ongoing Treatment With Alendronate or a Drug Holiday on the Fracture Risk in Osteoporotic Patients With Bisphosphonate Long Term Therapy

Inclusion Criteria

• •Postmenopausal women or men \> 60 years
• •DXA T-Score at lumbar spine, total hip or femur neck \<-2,0 before the start of the bisphosphonate therapy or at baseline or at least one low trauma vertebral fracture grade 2-3 or multiple low trauma vertebral fractures independent of bone mineral densitiy
• •Pretreatment with bisphosphonates for at least four years
• •Risk for hip and vertebral fractures min. 30% according to DVO-guideline for osteoporosis 2009
• •Signed informed consent