Alendronate treatment in osteogenesis imperfecta.
OBJECTIVE
Osteogenesis imperfecta (OI) is a chronic, disabling condition characterized by bone fragility resulting from defective production of type I collagen. Pamidronate therapy is the most extensively studied treatment and has proved beneficial. Our objective was to evaluate the effect of alendronate, a more potent bisphosphonate than pamidronate, in OI.


METHODS
Three patients (age, 3-7 years; mean, 5 years) (one case, type III; 2 cases, type IV) have been given alendronate (0.3-0.56 mg/kg per day orally) for 2 years. Number of fractures, ambulation, height growth, and bone mineral density by dual-energy x-ray absorptiometry (DXA) were followed up.


RESULTS
Bone mineral density improved significantly after the 2-year alendronate treatment, which increased by 47.8% to 106.6% in the lumbar spine and by 24% to 51.4% in forearm bones. The z-score of lumbar spine DXA values increased from -5.26 +/- 0.84 to -3.1 +/- 0.59. The mean of fracture rates did not change significantly. Only one of the patients was highly limited in ambulation. She had curved legs and could not sit without support before the treatment. She improved to walk with help by the treatment. Serum parathormone and alkaline phosphatase concentrations did not change significantly. No side effect was detected in clinical and laboratory evaluations.


CONCLUSIONS
The study suggests that alendronate is a safe and well-tolerated drug and that it could increase bone density in children with OI, all of which encourage further studies with the bisphosphonates that are more potent than pamidronate and can be used orally. In addition, this study is the first report using the forearm bone mineral density measurement in OI.
Madenci
Ercan
E
Departments of Physical Therapy and Rehabilitation, Gaziantep University, Medical Faculty, 27100 Gaziantep, Turkey. drmadenci@yahoo.com
Yilmaz
Kutluhan
K
Yilmaz
Mustafa
M
Coskun
Yavuz
Y
D015502:Absorptiometry, Photon; D019386:Alendronate / Q000627:therapeutic use*; D000469:Alkaline Phosphatase / Q000097:blood; D015519:Bone Density; D050071:Bone Density Conservation Agents / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D005260:Female; D050723:Fractures, Bone / Q000517:prevention & control; D006801:Humans; D008159:Lumbar Vertebrae; D008297:Male; D010013:Osteogenesis Imperfecta / Q000188:drug therapy*; D010281:Parathyroid Hormone / Q000097:blood; D011884:Radius; D016896:Treatment Outcome; D014457:Ulna
D050071:Bone Density Conservation Agents; D010281:Parathyroid Hormone; D000469:Alkaline Phosphatase; D019386:Alendronate