Primary care clinicians need to be ready to reduce the dose of drugs used for the control of blood sugar in patients with type 2 diabetes who follow a low carbohydrate diet (LCD) – or in some cases, stop them altogether.
The advice comes in a practical guide in the current issue of the British Journal of General Practice, which states that people with type 2 diabetes on a low carb diet must have their diabetic medication reduced to avoid hypoglycaemia.
The paper gives recommendations, for the first time, on how this should be done, giving specific guidance for each class of diabetes medication.
The LCD typically comprises <130g of digestible carbohydrates per day. Blood glucose levels fall substantially when patients follow an LCD, and continuing their usual regime without dose adjustment can put patients at increased risk of hypoglycaemia. Practice nurses have a key role to play in ensuring medication reduction happens in these patients.
The study is authored by leading advocates of a low carb approach, including Dr Campbell Murdoch, the chief medical officer of the Low Carb Program, which has been proven to help people with type 2 diabetes put their condition into remission and to save the NHS £835 per patient, per year, in reduced medication costs.
The guide says that sulfonylureas and meglitinides (e.g. repaglinide) should be reduced by at least 50% or stopped when an LCD is commenced. Insulin doses should also be reduced by about 30-50% and some patients with type 2 diabetes may be able to come off insulin completely over time. The potential risk of ketoacidosis with the SGLT2 inhibitors mean that it may be appropriate for most patients to stop their SGLT2i when an LCD is initiated. Other drugs – metformin, GLP-1 receptor agonists, DPP-4 inhibitors, thiazolidones and acarbose are safe to continue.
Murdoch C, et al. BJGP 2019;69:360-361
