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 (BILANZ)

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

Exclusion Criteria:

• Other pharmacological treatment of osteoporosis during the last 48 months
• Other bone diseases
• Malabsorption syndromes
• Renal insufficiency with a calculated creatinine clearance < 35 ml/min
• Diseases of the esophagus, delayed esophageal clearance
• UUnability to realise the intake instructions
• Hypocalcemia