Some people who have type 2 diabetes can achieve their target blood glucose levels with diet and exercise alone, but many also need diabetes medications.

“Most medications for type 2 diabetes are oral drugs. However, a few come as injections, such as insulin. Some people with type 2 diabetes may need to take insulin,” says Dr Bee Yong Mong, Head, SingHealth Duke-NUS Diabetes Centre, and Senior Consultant, at the Department of Endocrinology, Singapore General Hosp​ital​ (SGH), a member of the SingHealth group.

Examples of possible treatments for type 2 diabetes include:

  1. Metformin
  2. Sulphonylureas
  3. Thiazolidinediones (TZD)
  4. Acarbose
  5. DPP-4 inhibitors
  6. GLP-1 receptor agonists
  7. SGLT2 inhibitors
  8. Insulin

These medications listed are currently what is registered and available in Singapore.

Type 2 diabetes medication

  1. Metformin (e.g. Glucophage)

  2. Generally, metformin is the first medication used to treat type 2 diabetes. Metformin reduces the amount of sugar your liver makes.

    Side effects of metformin

    Nausea and diarrhoea are side effects of metformin, but these side effects usually go away as your body becomes familiar to the medicine.

  3. Sulphonylureas

  4. Sulphonylureas help your body secrete more insulin.

    Examples of medication in this class include:

    1. Glipizde
    2. Gliclazide
    3. Gliclazide MR (Diamicron MR)
    4. Glimepiride (Amaryl)​

    Side effects of sulphonylureas

    Potential side effects of sulphonylureas include hypoglycaemia (low blood glucose) and weight gain.

  5. Thiazolidinediones (TZD)

  6. Thiazolidinediones (TZD) make your body’s tissues more sensitive to insulin.

    Pioglitazone (Actos) is an example of thiazolidinedione.

    Side effects of thiazolidinediones (TZD)

    Thiazolidinediones (TZD) has been linked to weight gain and more serious side effects such as an increased risk of heart failure and fractures. Because of these risks, these medications are generally not a first-choice treatment.

  7. Acarbose (e.g. Glucobay)

  8. Acarbose works by slowing down the gut enzyme that turns carbohydrates into sugar. This results in a smaller rise in blood glucose levels following a meal.

    Side effects of acarbose

    Diarrhoea and bloating are possible side effects.

  9. DPP-4 inhibitors

  10. DPP4-inhibitors (dipeptidyl peptidase-4 inhibitors) increase levels of a group of gastrointestinal hormones called incretins, which increase insulin secretion and inhibit glucagon release. They reduce blood glucose levels without causing hypoglycaemia.

    Examples of DPP-4 inhibitors are:

    1. Sitagliptin (Januvia)
    2. Vildagliptin (Galvus)
    3. Linagliptin (Trajenta)
    4. Saxagliptin (Onglyza)

    Side effects of DPP4-inhibitors

    They can cause flu-like symptoms such as runny nose, sore throat and headache.

  11. GLP-1 receptor agonists

  12. GLP-1 receptor agonists come as injections but are not insulin. They are incretin mimetics. They slow digestion and help lower blood glucose levels. The use of GLP-1 receptor agonists is often associated with some weight loss.

    Examples of these medications include:

    1. Liraglutide (Victoza)
    2. Exenatide (Byetta)
    3. Exenatide Extended Release (Bydureon)
    4. Dulaglutide (Trulicity)

    Side effects of GLP-1 receptor agonists

    Possible side effects include nausea, vomiting and diarrhoea.

  13. SGLT2 inhibitors

  14. SGLT2 inhibitors are the newest diabetes drugs on the market. They work by preventing the kidneys from reabsorbing sugar into the blood. Instead, the sugar is excreted in the urine. Their use is often associated with weight loss and blood pressure reduction.

    Examples of SGLT2 inhibitors are:

    1. Canagliflozin (Invokana)
    2. Dapagliflozin (Forxiga)
    3. Empagliflozin (Jardiance)

    ​Side effects of SGLT2 inhibitors

    Side effects may include genital and urinary tract infections and low blood pressure.

  15. Insulin

  16. Som​e people who have type 2 diabetes need insulin therapy. In the past, insulin therapy was used as a last resort, but today it is often prescribed sooner because of its benefits.

    Insulin has to be injected because normal digestion interferes with insulin taken by mouth.

    Insulin injections involve using an insulin syringe or an insulin pen injector — a device that looks similar to an ink pen, except the cartridge is filled with insulin.

    There are many types of insulin, and they each work in a different way.

    Side effects of insulin


    Potential side effects include hypoglycaemia and weight gain.

Ref: O17