This is an update to the information on Avandia (Rosiglitazone) in light of recent evidence with regard to the risk of fractures.
ADOPT (A Diabetes Outcome and Progression Trial), a large study of Rosiglitazone in Type 2 diabetes involving almost four and a half thousand patients was recently completed. The patients were followed up for 4-6 years and the study was reported in the New England Journal of Medicine. The main aim of the study was to compare diabetes control in people taking Avandia (Rosiglitazone) to those taking other blood glucose lowering drugs such as glyburide (a sulphonylurea) or metformin.
In the ADOPT study, significantly more female patients who received rosiglitazone experienced fractures than did female patients who received either metformin or glyburide (9.3% vs. 5.1% and 3.5% respectively). Most of these fractures were in the upper arm (humerus), hand, or foot. These fracture sites are different from those associated with post-menopausal osteoporosis which usually occur in the hip or spine.
There was no difference in fracture risk observed among men. There was also no increase in the risk of fractures of the hip or spine in women, sites which are commonly involved in women after the menopause.
To summarise, nine out of every one hundred women taking rosiglitazone in this study suffered a fracture, compared to between three and five women taking alternative anti-diabetic drugs.
The precise mechanism for this increase in fracture rate is not known though we do have evidence from previous studies that Rosiglitazone has an impact on bone metabolism.
If you are currently receiving Avandia and are at greater risk of suffering a fracture, you may wish to discuss this with your doctor. If you are considering taking Avandia for diabetes control, your doctor will consider fracture risk before commencing treatment. Do not stop the medication without consulting your doctor or healthcare team.
Avandia has been used in people with type 2 diabetes since 1999. We know the drug causes fluid retention, swelling of the legs and avoid using it in people with heart failure. Damage to the liver which was a concern with Troglitazone, a related drug which has since been withdrawn has not been a prominent feature with Avandia.
The regulatory authorities in the United States and Europe have studies the evidence relating to Avandia and risk of fractures and have not chosen to recall or withdraw the drug from use.
Dr Nishan Wijenaike MD FRCP
West Suffolk Hospitals Diabetes Service