Use of Diazoxide in Acute Hypoglycaemia

The investigators know that intensive insulin therapy and tight glucose control is associated with reduction of diabetic complications. However, many patients on insulin don't achieve this because of the risk and the fear of hypoglycaemia (too low blood glucose). There has been a lot of work done recently looking at the mechanisms by which the brain detects hypoglycaemia. A key player is a potassium channel in the brain (KATP channel). Studies have shown that when these channels are opened, there is a release of hormones such as adrenaline that can help in raising blood sugars to counteract and increase awareness of hypoglycaemia. The investigators study aims to look at an old drug called diazoxide, which is able to open KATP channels. The investigators aim to see if diazoxide will amplify the release of hormones such as adrenaline when the blood sugar is low. If this is the case, this will aid quicker recovery following hypoglycaemia. The investigators aim to do this by performing a well established experimental protocol that has been performed safely over the last 20 years called a clamp study. The clamp study will involve slowly bringing the blood sugars down using insulin and intravenous glucose in a controlled fashion. The main outcome will be the hormonal responses (adrenaline response) at a blood sugar level of 2.5mmol/L. Symptoms of hypoglycaemia will be monitored, as well as working memory tests using standardised questionnaires. The design of the investigators study will be a randomised trial comparing the effects of diazoxide with placebo in which all patients will receive both diazoxide and placebo in random order (crossover design).