A RADAR (Rational Assessment of Drugs and Research) review on Avandia™ (rosiglitazone) and Avandamet™ (metformin plus rosiglitazone) for type 2 diabetes mellitus has been published and is available to access at the link below. This review was completed on behalf of the National Prescribing Service (NPS), which is an independent Australian organisation supporting the quality use of medicines. The authors summarise as follows (taken directly from the source):
• Rosiglitazone improves glycaemic control but there is a lack of evidence that it improves diabetes–related clinical complications and mortality. Prescribers should consider this — along with recently emerging safety information — when assessing the ratio of potential harms and benefits for each patient.
• Rosiglitazone is no longer indicated in combination with insulin or for triple oral therapy in combination with metformin and a sulfonylurea [PBS listings for these indications have been removed].
• Rosiglitazone is a third-line choice. It may still be considered as part of dual therapy when either metformin or a sulfonylurea is contraindicated or not tolerated.
• Insulin should also be considered instead of rosiglitazone in these scenarios.
• Do not use rosiglitazone in people with heart failure or a history of heart failure.
• Avoid using rosiglitazone in people with ischaemic heart disease. Take particular care when prescribing the drug to people with a high risk of cardiovascular events.
• Bear in mind the possibility that rosiglitazone may increase the risk of a myocardial infarction.
• A large clinical trial found an increased rate of fractures of the humerus, hand and foot among women using rosiglitazone.
• Wait 8 weeks before increasing the dose, as the full effect of the drug may not be seen before this time. In clinical trials of glitazone treatment, 25% to 30% of patients had no improvement in glycaemic control.
• Establish the effective and tolerated dose of each component as single drugs before considering the rosiglitazone with metformin combination tablet. Do not use combination tablets for patients taking more than 2 g/day of metformin because the maximum recommended daily dose of rosiglitazone will be exceeded.
Rosiglitazone was recommended for listing by the Pharmaceutical Benefits Advisory Committee (PBAC) as dual oral therapy with metformin or a sulfonylurea on a cost-minimisation basis compared with insulin.