DPP-4i (gliptin)

A newer class of oral antidiabetic medicine is dipeptidyl peptidase 4 inhibitors (DPP-4is or gliptins), which block the DPP-4 enzyme that breaks down the gastrointestinal hormone incretin (used to stimulate insulin production after eating) and prevent glucagon production during digestion (glucagon releases glucose into the blood from stores in the body). 

By blocking the enzyme that breaks down incretin, more insulin is produced. DPP-4is can be useful for patients wanting to lose weight as they slow the rate of stomach emptying and glucose absorption. DPP-4i treatments include saxagliptin (Onglyza), alogliptin (Vipidia), linagliptin (Trajenta), sitagliptin (Januvia) and vildagliptin (Galvus).

Caution must be taken using a DPP-4i in individuals with renal impairment (where it may be necessary to reduce the dose). Concomitant doses of sulfonylureas or insulin may need to be reduced.

Glucagon-like peptide 1 (GLP-1)

GLP-1s, also known as incretin mimetics, are a group of injectable antidiabetic drugs. This group only tends to be prescribed once oral treatments have been exhausted. Treatments in this group include exenatide (Byetta and modified release Bydureon), liraglutide (Victoza), lixisenatide (Lyxumia) and dulaglutide (Trulicity).

Acute pancreatitis is a rare but serious adverse effect of GLP-1s so where symptoms such as persistent, severe abdominal pain, nausea and or vomiting present, medical advice must
be sought promptly. 

SGLT-2 inhibitors

Unlike all the other antidiabetic drugs, SGLT-2 inhibitors do not work on insulin but reversibly inhibit sodium-glucose co-transporter 2 (SGLT-2) in the kidneys to reduce glucose re-absorption and increase urinary glucose excretion. The result is a reduced amount of glucose in the bloodstream but urine will test positive due to its mode of action. Patients may also see a reduction in blood pressure and body weight due to glucose excretion from the body.

Dapagliflozin (Forxiga), canagliflozin (Invokana) and empagliflozin (Jardiance) are
all SGLT-2 inhibitors.