What's New in Diabetes Care
Introduction to diabetes
Types of diabetes
Diagnosis
Risk factors & screening

What's New in Diabetes Care

New Treatment in Diabetes

• Sitagliptin (DPP-IV inhibitor)
• Inhaled insulin

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Sitagliptin - DPP-4 inhibitor (Januvia®)

Glucagon-like peptide-1 (GLP-1) is an important incretin hormone in maintaining the glucose homeostatsis in the body. This hormone is secreted from the gastrointestinal tract in response to food intake and exerts it effects via:

• Increased insulin secretion from the beta cells in the pancreas when the blood glucose level is raised
• Blocking glucagon production during the period of elevated blood glucose. Glucagon is a hormone secreted from the alpha cells in the pancreas that causes the release of glucose from the liver during the fasting state.
• Triggering a feeling of satiety, therefore reduces appetite and food intake
• Inhibition of gastric emptying resulting in reducing food absorption from the small intestine.

GLP-1 has a very short half-life of less than 2 minutes. It is rapidly broken down by an enzyme called dipeptidyl peptidase (DPP)-IV. Inhibition of DPP-IV improves the glycemic control by preventing the degradation of GLP-1.

Sitagliptin phosphate tablets (Januvia®, made by Merck and Co, Inc) is the first available orally administered DPP-IV inhibitor. It has been approved by the US Food and Drug Administration (FDA) in October 2006 for use in adult patients with type 2 diabetes mellitus when diet and exercise or current anti-diabetic drugs fail to control blood glucose adequately. It is given as once daily dose, and can be used alone or as a combination with metformin or thiazolidinediones e.g. pioglitazone HCl and rosiglitazone maleate. Side effects of Sitagliptin include runny nose, sore throat, headaches and gastrointestinal effects. However it does not cause weight change or hypoglycemia.

Inhaled insulin

Inhaled insulin has recently approved by the FDA in January 2006 for treatment of diabetic individuals who require insulin therapy. This first inhaled version of insulin is called Exubera from Pfizer Inc. Several trials have shown that the inhaled insulin is as effective as multiple insulin injections therapy. There is no significant difference in blood glucose control between the group using inhaler and patients using needles. But patient satisfaction and quality of life improved dramatically for those who were taking the insulin inhalers. It would be appropriate for those who have needle phobia.

The new portable aerosol delivery system is similar to an asthma inhaler. It delivers a short-acting powder form of insulin into the lungs within minutes. It is to be taken before each meal. However, a long-acting insulin still needs to be given each day by injections. Furthermore it may be less effective during pneumonia or may work differently in those with chronic lung disease e.g. asthma and chronic obstructive pulmonary disease, or who smoke. Reported side effects include coughing, shortness of breath and dry mouth. Safety concerns remain an issue due to a lack of long-term experience with insulin inhaler.