The natural history of type 2 diabetes is one of progressive beta cell failure. Most patients require increasing doses of oral hypoglycaemic agents eventually needing transfer to insulin treatment. The prospect of new oral agents which may help delay or prevent the need for insulin is an exciting new development in diabetes care.
Saxagliptin or Onglyza is a new oral blood glucose lowering agent which was recently launched in the UK. It has similar properties to two other oral agents, sitagliptin (januvia) and vildagliptin (Galvus) which are already available to prescribe. This new class of drugs is known as DPP-IV (dipeptyl peptidase-IV) inhibitors.
Saxagliptin reduces blood glucose concentrations by enhancing the effects of ‘incretins’. These drugs are therefore also known as ‘incretin enhancers’.
Incretins are hormones which are produced by the intestines in response to food. These hormones have recently been of great interest to diabetologists and have lead to the discovery of several new glucose lowering agents.
When you have a meal various hormones (chemicals) are released by cells in the gut (bowel) wall. These hormones help stimulate the release of insulin by the pancreas. It has been shown that people with type 2 diabetes have an impaired ‘incretin effect’.
Incretin hormones have a very short life-span in circulation – as they are rapidly destroyed by DPP-IV.
By opposing the action of DPP-IV, DPP-IV inhibitors help to prolong the incretin effect. This helps reduce blood glucose levels.
When compared to other blood glucose lowering agents:
There are no major differences between the three DPP iv inhibitors currently available in the UK.
It is known that people with type 2 diabetes have progressive loss of beta cell function. It is possible that Saxagliptin may help preserve pancreatic beta-cell function.
Saxagliptin is taken orally and is administered once daily. It is available as a 5mg film coated tablet.
Saxagliptin was launched in the UK in October 2009 and is now available for prescription to patients.
Dr Nishan Wijenaike
West Suffolk Diabetes Service
Bury St Edmunds