Gliptins for type 2 diabetes

‘Gliptins’ is the nickname given to a group of medicines called dipeptidyl peptidase-4 (DPP-4) inhibitors. The gliptins (active ingredient with brand name given in brackets) are:

The gliptins are all relatively new medicines for diabetes. Linagliptin, saxagliptin, sitagliptin, alogliptin and vildagliptin are all active ingredients in these medicines.

Note about medicine names

Most medicines have two names: the active ingredient and the brand name. The active ingredient is the chemical in the medicine that makes it work. The brand name is the name given to the medicine by its manufacturer. There may be several brands that contain the same active ingredient. This website uses active ingredient names, with brand names in brackets. We also discuss medicines in groups or ‘classes’, when their effects or actions are very similar.

The gliptins are effective at lowering blood glucose, but they have not been used for long enough to know whether they also reduce the long-term complications of diabetes (such as heart disease and stroke). This will only become clear when they have been used by more people for longer periods of time.

Diabetes is a progressive condition. After a while, a single medicine will not be enough to control blood glucose levels. It could be months or years before this happens — but once it does, another kind of diabetes medicine will need to be added to metformin (and/or a sulfonylurea) to control blood sugar.

The gliptins are not taken on their own, but can be added to metformin, a sulfonylurea, or a glitazone.

Most commonly, people will start taking both metformin and a sulfonylurea when blood glucose cannot be controlled with a single medicine alone. However, some people can’t take this combination of medicines because they experience bad side effects, or they have another medical condition or another reason that means they can’t take metformin or a sulfonylurea (i.e. a contraindication). These people may have another kind of diabetes medicine added to their metformin (or sulfonylurea) instead.

The gliptins are one kind of diabetes medicine that can be used when this happens.

What do gliptins do?

Gliptins increase the amount of insulin in the blood when they are taken with metformin, a sulfonylurea, or a glitazone. They also reduce the amount of glucose produced by the liver.

What are the benefits of taking gliptins?

  • Gliptins lower blood glucose levels at the recommended doses.
  • All five gliptins appear to be equally effective.
  • When taken together with metformin, gliptins don’t seem to increase the chances of hypoglycaemia or weight gain.
  • They are oral medicines and so are an alternative for people who cannot take a combination of metformin and a sulfonylurea.

Because gliptins are a new group of medicines, their long-term benefits are not fully known. For example it has not been shown that gliptins reduce the risk of developing the complications of diabetes (such as heart disease and stroke). This will only become clearer when they have been used by more people for longer periods of time, or when more research is done.

Who can take gliptins?

People with type 2 diabetes whose:

You may not be able to take a gliptin if you have liver or kidney problems. Talk to your health professional as they may need to take this into account before deciding about prescribing a gliptin.

What are the side effects of gliptins?

Gliptins can cause:

  • dizziness, headaches and cold-like symptoms
  • infections of the respiratory and urinary tract
  • hypoglycaemia and weight gain when used with a sulfonylurea, but not with metformin.

Allergic reactions to the gliptin occur very rarely. Seek medical attention if there is any swelling of the face, mouth, tongue or throat.

Saxagliptin (Onglyza) may also increase the chance of bone fractures.

Pancreatitis (inflammation of the pancreas that can result in severe, long-lasting abdominal pain) is rare, but has developed in a few people after starting linagliptin (Trajenta), sitagliptin (Januvia) and vildagliptin (Galvus). But it’s not known for sure if these medicines caused the pancreatitis. Talk to your health professional if you have any concerns.

Because gliptins are relatively new medicines, all of their side effects are not fully known. This will only become clear when they have been used by more people for longer periods of time.

To find out more, read our Medicine Update articles on saxagliptin, sitagliptin and vildagliptin.

Who can I ask about side effects?

If you are concerned that you may have had side effects related to a medicine, seek medical advice or call the Adverse Medicines Events (AME) line on 1300 134 237 from anywhere in Australia (Mon–Fri, 9am–5pm) to report and discuss possible side effects.

Interactions

It is important to tell your health professional about all the medicines you are taking — including prescription, over-the-counter and complementary medicines (herbal, ‘natural’, vitamins and minerals) — as they may interact with diabetes medicines and affect your blood glucose levels. This may mean that your doctor will need to adjust the dose of your gliptin, or make changes to your other medicines.

The gliptins are new medicines so not all of their potential interactions with other medicines are known.

Some medicines are known to affect blood glucose levels. Click on the following links to view tables that list some of these medicines:

Apart from these medicines, which can affect the way the gliptins control blood glucose:

  • saxagliptin (Onglyza) may also interact with medicines that treat fungal infections (antifungals), such as ketoconazole.* You may need to take a lower dose of saxagliptin.
  • linagliptin (Trajenta) can interact with the antibiotic rifampicin - rifampicin can decrease the amount of linagliptinin your blood and affect how well it works. You may need to take a different gliptin.

Read the Medicine Update issues about sitagliptin, vildagliptin and saxagliptin for more information.

*As there are often many different brands of one medicine, we have only listed the active ingredient of the medicine here. To find out more, read our information about active ingredients and brand names.

Phone for medicines information

Call Medicines Line on 1300 MEDICINE (1300 633 424) to get information about your prescription, over-the-counter and complementary medicines (herbal, 'natural', vitamins and mineral supplements) from a pharmacist. Your call will be answered by healthdirect Australia.