Given the multiple physiological defects seen in people with type 2 diabetes, treatment for type 2 diabetes often requires a combination of different medications that work on different mechanisms. The medications used to treatment type 2 diabetes are discussed below.
Metformin
Metformin is the recommended first-line treatment for most people with type 2 diabetes. Metformin comes in 2 forms, immediate-release and extended-release preparations. They both work similarly, but the extended-release metformin can be taken once a day, and has less gastrointestinal side effects.
Side effects of metformin are uncommon. The most commonly seen side effect is abdominal discomfort which may be accompanied by loose stool. This tend to be mild, but can be significant enough to warrant discontinuation in some patients. In people with advanced kidney disease or who are acutely unwell, metformin can cause lactic acidosis, but this is a rare occurrence.
A derivative of metformin, called imeglimin, is currently approved for use in Japan, but is not available in Malaysia at the moment.
Sulfonylureas
Sulfonylureas are the oldest oral medication available for type 2 diabetes but in recent times have been largely superseded by newer and safer medications. Sulfonylureas are very cheap and very effective in the first few months of treatment, making it still widely used in many parts of the world.
Side effects of sulfonylureas include weight gain and hypoglycaemia. People with kidney disease, liver disease, and older people may have a higher risk of hypoglycaemia with sulfonylurea, and needs additional caution. Newer generation sulfonylureas such as gliclazide and glimepiride have a lower risk of hypoglycaemia than older generation sulfonylureas such as glibenclamide.
SGLT-2 inhibitors
SGLT-2 inhibitors work by promoting glucose excretion into the urine. Examples of SGLT-2 inhibitors include empagliflozin, dapagliflozin, canagliflozin, ertugliflozin, and luseogliflozin. By promoting glucose excretion in the urine, SGLT-2 inhibitors also promote salt excretion and calorie loss via the urine, leading to a mild improvement in blood pressure and body weight.
SGLT-2 inhibitors are an important class of diabetes medication as they have been shown to reduce the risk of cardiovascular events, death, kidney disease, and heart failure in people with and without diabetes. Because of these benefits, they are highly recommended for people with diabetes who also have underlying cardiovascular disease, kidney disease, or heart failure.
Incretin-based therapies
Incretin-based therapies work by augmenting or mimicking the effect of the incretin hormones which regulate blood glucose. There are 2 subgroups of incretin based therapy, DPP-4 inhibitors and GLP-1 receptor agonists.
DPP-4 inhibitors such as sitagliptin, linagliptin, saxagliptin, and vildagliptin are very safe diabetes medications, with side effect profiles almost similar to placebo in clinical trials. They are often used in people who are at particular risk of hypoglycaemia or other treatment-related side effects.
GLP-1 receptor agonists include liraglutide, semaglutide, dulaglutide, exenatide, and lixisenatide. They are the only currently available injectable non-insulin treatment for diabetes, with effectiveness being comparable to basal insulin in selected patients. Liraglutide, semaglutide, and dulaglutide have also been shown to reduce the risk of cardiovascular disease and progression of kidney disease in people with diabetes. Side effects of GLP-1 receptor agonists include nausea, but vomiting is less common.
A third subgroup of incretin-based therapy, dual GLP-1/GIP agonist, is currently in the final stages of clinical trials.
Insulin
Insulin treatment is discussed in a separate topic.