Treating hyperglycaemia used to be straightforward. In fact, until the late 1990s, the clinicians choice was limited to Metformin, sulphonylureas and human insulin. However, over the last 15 years, our increasing understanding of the pathophysiology of diabetes has lead to a plethora of new agents belonging to a variety of classes – with more in the pipeline. Whilst metformin is universally considered first line therapy, increasingly the issue has been what next?
Current NICE guidance issued in 2008 and updated to take account of newer agents in 2011 has become a bit of a spiders web as it progresses through different drug classes eventually leading to insulin with a clear guide to the use of NPH insulin over the more expensive analogues. However the clear intention is that sulphonylureas should be second line probably due to cost & experience in their use. The guidance also contains a number of caveats aimed to help in drug choice. However the intention of the updated guidance is to focus on a patient centred approach. This is the aim of yet another set of guidelines published in 2012 in the form of a position statement from the ADA and EASD.
The underlying principles of this new guidance is that it should be patient centred, less prescriptive and with a recognition that patients will often require multiple agents to control blood glucose. An HbA1c goal of 7% has been set but it is recognised that this target should be individualised – possibly being higher in patients with advanced cardiovascular risk (following the ACCORD trial) but also lower in newly diagnosed and motivated patients. In summary, after metformin, any drug class (thiazolidenedione, gliptin, sulphonylurea, GLP-1 analogue or even insulin) can be prescribed second, third and fourth line depending on the patients requirements.
Whilst this all sounds very sensible comprehensive, it does have some drawbacks. Already it is outdated as it does not mention a new class of agents – the SGLT2 inhibitors. Furthermore, after metformin, the clinician can choose from ~50 different combinations of treatment as the patient progresses through treatment options. Whilst this is very manageable for those clinicians who are used to dealing with large numbers of patients with diabetes and are adept at using different drug classes, for those with less experience thy can be confusing and possibly lead to the use of inappropriate drug classes and combinations – precisely what the guidance is designed to avoid.
Dr Mark Freeman