Medications for type 2 Diabetes

If you are prescribed medication for your diabetes, it is important that you understand:

  • How the medication works
  • What dose to take
  • When to take the medication
  • How often to take the medication
  • What to do if you miss taking a dose
  • If you are at risk of hypoglycaemia (low glucose levels) and how to treat it
  • How your medication should be stored
  • Possible side effects you may experience

Your doctor and/or pharmacist should be able to answer any questions that you have.

Medications available in Australia

There are six different classes of medication for type 2 diabetes that are currently available in Australia.

These include:

  1. Biguanides
  2. Sulphonylureas
  3. Thiazolidinediones (Glitazones)
  4. Alpha-glucosidase Inhibitors
  5. Dipeptidyl peptidase 4 (DPP4) inhibitors
  6. Incretin mimetics

How will I know which medication is best for me?

Your doctor will make this decision based on your general health, the other medication you may already be taking, and how diabetes is affecting your body.

One medication may not control your blood glucose well enough, and two or even three medications may be used in combination. Insulin may also be added or tablets stopped and replaced with insulin.


Chemical name some brand names
METFORMIN Diabex®, Diaformin®,  Formet®, Metforbell®, Glucohexal®, Glucomet®, Glucophage®, Genrx metformin®, Genepharm metformin®
METFORMIN ER Diabex®,Diaformin XR®, Metex XR®

Metformin is often the first medication prescribed to people with type 2 diabetes.

How does it work?

Metformin helps to lower blood glucose levels by:

  1. Reducing the amount of stored glucose released by the liver
  2. Slowing the absorption of glucose from the small intestine
  3. Helping the body to become more sensitive to insulin

Points to remember about Metformin:

  • Should be taken with, or after meals
  • It can be started at a low dose and increased slowly if gastrointestinal disturbances are a problem
  • Does not cause weight gain, and may help with weight loss
  • Metformin by itself will not cause hypoglycaemia
  • Metformin may need to be stopped before surgery or procedures that require the use of radio-opaque dye such as a coronary angiogram. (Always check with your doctor before stopping medication)
  • Side effects can include nausea, diarrhoea, and a metallic taste in the mouth



Chemical name Brand names
GLICLAZIDE Glyade®,  Mellihexal®, Nidem®, Genrx Gliclazide®
GLICLAZIDE ER Diamicron MR®, Glyade MR®, Oziclide MR®
GLIBENCLAMIDE Daonil®, Glimel®
GLIPIZIDE Melizide®, Minidiab®
GLIMEPIRIDE Amaryl®, Dimirel®, Aylide®, Diapride®, Gilmepiride Sandoz®

How do sulphonylureas work?

Sulphonlyureas help lower blood glucose levels by stimulating the pancreas to release more insulin.

Points to remember about Sulphonylureas:

  • Tablets should be taken just before a meal
  • Sulphonylureas can cause hypoglycaemia (low glucose levels) so it is important to have regular meals
  • A person should not be prescribed more than one type of sulphonylurea. For instance, if a person is taking Diamicron MR® they should not also be taking Daonil®
  • Possible side effects include weight gain, rash (rare), stomach upset and jaundice


Thiazolidinediones (glitazones)

Chemical name

Brand Name

These medications are usually  tried when the maximum dose of sulphonylurea has been reached.

How do they work?

Glitazones help to lower blood glucose levels by:

  1. making your own insulin work more effectively, especially in muscle and fat cells
  2. reducing the amount of glucose released into the bloodstream from the liver

Points to remember about Glitazones:

  • Taken on their own glitazones do not cause hypoglycaemia (low blood glucose)
  • Pioglitazone may also improve cholesterol and triglyceride levels
  • Glitazones do not have to be taken with a meal
  • A possible side effect is weight gain, mainly due to fluid retention and increased fat tissue
  • Glitazones should not be taken by people with heart failure or liver disease. If you experience any oedema (fluid retention) unexplained rapid weight gain, trouble breathing, unusual fatigue you should see your doctor as soon as possible
  • Regular liver function checks are recommended, especially during the first year of treatment.
  • They are not suitable for women who are pregnant or breast feeding
  • Another possible adverse effect is a small increased risk of fractures in the arm, hands and feet has been reported, particularly in women

The Therapeutic Goods Administration (TGA) is considering the approval and use of rosiglitazone in Australia. The current TGA advice may be found at:


Alpha-glucosidase inhibitors

Chemical name Brand name
ACARBOSE Glucobay®

How does it work?

Alpha-glucosidase inhibitors lower blood glucose levels after meals by slowing down the digestion and absorption of certain dietary carbohydrates in the intestine (bowel).

Points to remember about Alpha-glucosidase inhibitors:

  • Take with the first bite of a meal
  • It should be started at a low dose and increased slowly to reduce side effects
  • Taken on it’s own, it won’t cause hypoglycaemia
  • If hypoglycaemia does occur due to other medication (such as a sulphonylurea), it must be treated with glucose such as glucose tablets, gel or Lucozade®
  • It should not be taken by women who are pregnant or breast feeding, or people with inflammatory bowel disease or malabsorption syndrome
  • Possible side effects include flatulence (wind), bloating and diarrhoea


Dipeptidyl peptidase 4 (DDP-4) inhibitors

Chemical name Brand name

DDP-4 inhibitors are a relatively new class of drugs to be used in the treatment of type 2 diabetes.

How do they work?

The DDP-4 inhibitors lower blood glucose levels by inhibiting the enzyme DPP-4. This works to prolong the action of the incretin hormones. Incretin hormones lower blood glucose levels after a meal by:

  1. Stimulating insulin release from the pancreas
  2. Reducing the secretion of glucagon (a pancreatic hormone), which will decrease the release of  stored glucose from the liver

Points to remember about DDP-4 inhibitors:

  • A tablet usually taken once or twice a day by mouth, with or without food
  • Take at about the same time each day
  • You are unlikely to develop a hypo (low blood glucose) unless you are also taking a sulphonlyurea
  • These medications may cause headaches and nausea, and may increase the chance of catching a cold
  • Seek urgent medical attention if rash, hives or swelling of the face, lips, mouth, tongue or throat occur during treatment
  • DDP-4 Inhibitors should not be taken by women who are pregnant or breast feeding or children under 18 years of age
  • The dose of Sitagliptin may need to be reduced if you have renal dysfunction
  • Vildagliptin and Saxagliptin should not be used if you have moderate or severe renal impairment
  • Vildagliptin is not suitable for people with liver problems.


 Incretin mimetics

Chemical name Brand name

Incretin mimetics are a relatively new class of drug to be used to treat type 2 diabetes. Although Exenatide comes in injection form, it is different to insulin and is not a substitute for insulin.

How does Exenatide work?

Incretin mimetics mimic the effects of the body’s own ‘incretin hormones’. These hormones help to control blood glucose levels by:

  1. Stimulating insulin release from the pancreas
  2. Reducing the secretion of glucagon (a pancreatic hormone), which will decrease the release of  stored glucose from the liver
  3. Slows down emptying of the stomach so food is absorbed more slowly from the intestine (gut)
  4. Promotes a feeling of fullness and reduces appetite

Points to remember about Exenatide:

  • It is given by injection, twice daily within one hour of morning and evening meals
  • It is used in addition to metformin or a sulphonylurea or both
  • It must be stored in the fridge between 2 – 8 ○ C
  • Possible side effects include nausea, vomiting, and diarrhoea
  • It is not a substitute for insulin and is not suitable for people with type 1 diabetes
  • When taken with Metformin alone, Exenatide doesn’t usually cause low blood glucose levels. However this can occur when it’s taken with a sulphonylurea
  • It can help to reduce appetite, and weight
  • Pen needles are available free of charge through National Diabetes Services Scheme (NDSS) for registered users of Byetta®
  • In rare cases Exenatide (Byetta®) has been associated with pancreatitis (inflammation of the pancreas). Severe abdominal pain and vomiting when taking Byetta® should be reported to your doctor promptly.



For many people with type 2 diabetes, more than one medication will be needed to achieve target glucose levels. Combination medications are able to provide the action of two classes of medications in the one tablet.

Chemical name Brand name



The decision that your doctor makes with you in regard to which medication or insulin is appropriate for you will depend on many factors, including how long you have had diabetes, other medical conditions you have, your weight and other lifestyle issues and preferences. Medications work best when they are taken regularly and as prescribed by your doctor.

The main goal is that your blood glucose levels are within the target range as much as possible in order to prevent both short and long term complications of diabetes.

Remember that physical activity and healthy eating are the key to good management of type 2 diabetes even if you are taking medication or insulin.

Ask your doctor or pharmacist for more information about your medication and how to take it effectively. If cost is a problem ask your doctor or pharmacist about generic brands which may be less expensive.