<<Print>>

Interesting time with our diabetics last week. Wednesdays are the diabetic clinic days. We decided to educate the clients on oral anti-diabetic medications.

This is a feedback from the Disposal of Unused/Unwanted Medicines Programme (DUMP). A client asked why we were focusing on oral anti-diabetic medications. Lack of understanding of the disease and medications contribute to inappropriate use of medications and a drawback to the achievement of treatment outcomes.

Diabetes mellitus is either the absolute or relative lack of insulin in the body. You need insulin to facilitate the utilisation of glucose by the cells of the body.

There are two main types of diabetes-Type 1 and Type 2. In Type 1 diabetes the body is unable to produce insulin so you depend on external insulin to control your blood sugar.

Type 2 diabetes is either due to inadequate secretion of insulin or insulin resistance, that is the cells are not sensitive to insulin and therefore insulin is unable to move glucose into the cells. Type 2 diabetes accounts for about 90 per cent to 95per cent of all diagnosed cases.

We began the session by showing our clients at the pharmacy waiting area the various oral anti-diabetic medications available at the clinic.

These were Metformin, Glibenclamide, Gliclazide, Glime-piride, Tolbutamide, Pioglitazone, Vidagliptin, and Saxagliptin.

The clients could identify the oral antidiabetics they used to manage their diabetes mellitus. The next question was to find out from the clients how each of these medicines worked to control blood sugar. None could explain.

There were clients who used Metformin alone. There were clients who used Metformin plus either Glibenclamide or Gliclazide or Glimepiride or Tolbutamide or Vidagliptin or Saxagliptin or Pioglitazone.

There were clients who used Metformin plus Vidagliptin or Saxagliptin plus either Glibenclamide or Gliclazide or Glimepiride.

There were clients who used Metformin plus Pioglitazone plus either Glibenclamide or Gliclazide or Glimepiride. The medicines used in Type 2 diabetes are either to stimulate the beta cells of the pancreas to produce more insulin or to increase the sensitivity of the cells to insulin.

A discussion of antidiabetics will always focus on Metformin. Indeed a client asked why so many diabetics in the country are on Metformin. Metformin acts by enhancing the action of insulin,

especially in the liver and skeletal muscle. Metformin increases the sensitivity of the cells to insulin. It also inhibits production of glucose by the liver and delays absorption of glucose from the gut.

There is evidence of Metformin having a favourable effect on cardiovascular risk associated with Type 2 Diabetes. It depresses appetite. It is clear from the fore-going why you would find many diabetics on Metformin.

It could cause some stomach discomfort and therefore better taken after food. It is taken either once or twice or thrice daily on the advice of the doctor.

Examples of medicines that directly stimulate the beta cells of the pancreas to produce insulin include Glibenclamide, Gliclazide, Glimepiride, Tolbutamide.

It means these are effective if the body has residual capacity to produce insulin from the pancreas.They are referred to as Sulphonylureas.

There is another group that stimulates the beta cells too- the Meglitinides. A typical example in this group is Repaglinide. The Meglitinides are not readily available on the market.

Glibenclamide is by far the widest used agent in this group of oral antidiabetics. Glibenclamide is best given 15 to 30minutes before food to allow the insulin which is released as a result of taking the medication to cope with the food. We had to stress that Gliben-clamide is taken once or twice daily and never, ever three times daily. One could easily suffer low blood sugar (hypogly-caemia) because of its long duration of action.

The only one in the group that may be taken three times daily is Tolbutamide. This is usually given to the elderly because of its short duration of action. We moved on to Pioglitazone. It is in a class of antidiabetics called Thiazolidinediones.

These are referred to as insulin sensitisers because they increase the sensitivity of the cells to insulin. As a result more glucose is removed from the blood.

It also reduces the production and secretion of glucose into the blood by the liver. However it takes one about two weeks to feel the effect of Pioglitazone unlike other oral antidiabetics.

It has taken once daily (same time) without strict regard to meals. We then moved on to Saxagliptin and Vidagliptin.

A client commented that she used to be on Glimepiride 2mg daily together with Metformin 1g twice daily but his doctor switched him onto Saxagliptin 5mg daily plus Metformin 1g twice daily. Saxagliptin, Vidagliptin, and Sitagliptin belonged to a new group of oral antidiabetics called DPP4 inhibitors.

It is been found that some hormones in the gut called incretins (INtestinal seCRETion of INsulin) serve as first line triggers for insulin release from the pancreas in the presence of food.

The incretins are neutralised by the Dipeptide peptidase enzyme (DPP4). The DPP4 inhibitors such as Saxagliptin and Vidagliptin block DPP4 enzyme and thereby facilitate prolonged release of insulin by the prolonged action of incretins in the presence of food.

They have other actions which I intend to detail in another article. They can be taken with or without food. Saxagliptin is taken once daily while Vidagliptin is taken twice daily.

There is another group called Alpha glucosidase inhibitors which reduce the rate of digestion of carbohydrates in the gut. A typical example is Acarbose. Someone asked why some diabetics on oral medications are put on small amounts of insulin sometimes. A lot of monitoring goes together with the management of diabetes in Type 2 person.

There are times when the doctor after thorough assessment will decide that you still require some amount of external insulin at some point in the day for better control of your blood sugar.

The feedbacks from the clients were really interesting. They were asked to clean their homes of all unused/unwanted medicines and return them to Cocoa Clinic for Safe Disposal.