Type 2 Diabetes Oral Medication

Type 2 Diabetes and Oral Medication

For people with Type 2 diabetes the first and most important thing to consider is possible lifestyle changes to help manage the disease but sometimes these changes alone are simply not enough.

Fortunately for people with Type 2 diabetes, the pancreas is still functioning and producing insulin; there are just problems with how effective it is. This is a good thing because it promises more options for treatments, especially in comparison to Type 1 diabetes where giving insulin injections is currently the only viable option. Alternatives that are much more convenient become real possibilities, such as oral tablets rather than frequent injections.

Type 2 Diabetes Oral Medication

There are three main types of oral drugs for Type 2 diabetes, those that:

  • reduce insulin resistance
  • increase insulin production
  • decrease the absorption of glucose

Each of these methods can lower blood glucose, which is the primary aim of Type 2 diabetes management.

Let’s take a look.

Reduce insulin resistance

The whole problem of Type 2 diabetes is the insulin we have isn’t working properly.

So why not start at the crux of the issue?

This is exactly what these drugs do. They decrease the amount of glucose the body makes and encourage the body to use the glucose it has for energy.

In doing so, even without increasing insulin the blood sugar can be managed effectively.


This is by far the most common drug used for Type 2 Diabetes.

Why? It does a good job and the risks of taking it aren’t too bad.

It doesn’t actually increase the levels of insulin, so there is no risk of hypoglycaemia (commonly known as low blood sugar), unlike most of diabetic medications.

Stomach upset, vomiting and diarrhoea are side effects that are commonly noted by people taking metformin. Fortunately, there is an easy solution. As this usually occurs when treatment starts, it is helpful to start at a lower dose and gradually increase it as needed – taking doses with food also helps. These symptoms fade over time, so there is hope for someone who experiences this.

Another thing that can occur is weight loss. Although this is an unintentional effect of metformin, it can actually be a good thing. As a large proportion of people with Type 2 diabetes are overweight, weight loss is usually an added benefit rather than a negative aspect.

Lactic acidosis is a more serious effect that is occasionally associated with metformin, which involves damage to the body’s cells due to acid levels. This can be fatal, and the reason behind the link is unclear. This is very uncommon, however, and most people reap the benefits of metformin without experiencing this.

Pioglitazone and Rosiglitazone

Like metformin, these drugs have a noticeable positive effect on the the glucose in the body. They are less commonly used, however, due to the other effects that are associated with. These things include limb fracture, fluid retention, heart failure and cardiovascular disease.

This does not mean that someone taking one of these drugs will certainly experience these things. It simply means that in the past it has been noted, so we should be aware of the possibility.

For this reason, these drugs are still used, but metformin is the preferred first option.

Increase insulin production

These drugs work by encouraging the pancreas to work harder and produce more insulin.

They are often used in addition to metformin (but can be used alone) so that one produces more insulin AND has less resistance to the insulin available. A double whammy effect.

There is one side effect that is prominent across the board, for all drugs that increase insulin production:

If the dose is too high and too much insulin is produced, the blood sugar will become too low, known as hypoglycaemia.

Glipizide and Glimepiride

These two are the most common of drugs used to increase production of insulin.

Similar to metformin, some gastrointestinal upset (such as nausea, vomiting and/or diarrhoea) might occur when taking these. Another worry is possible weight gain, particularly as obesity is strongly associated with Type 2 Diabetes.

For these things, it is best to keep an eye on how it effects you as an individual. Try taking doses with food if stomach upset occurs, and if weight gain is an issue you could consider changing therapy if you are already paying attention to your diet.


This works similarly to glipizide and glimepiride, but works for a shorter time.

What this means in a practical sense is we need to take doses more often. Usually they work better to control mealtime glucose increases, rather than continual maintenance.

In reality, this is used as a second option, when someone can’t tolerate other drugs to increase insulin production well (e.g. allergies).

Decrease glucose absorption

There is only one drug that is in this category: acarbose.

This is taken with meals to delay carbohydrate digestion and hence glucose absorption.

Unfortunately, this doesn’t come without other effects. It is common to experience bloating, diarrhoea and to have more gas than usual as a result of the change in digestion.

Usually acarbose is used with other drugs when therapy isn’t meeting the requirements it needs to.

Last resort

Finally, we can look to therapy with insulin when our blood glucose levels are still not at the right mark.

The reason insulin is looked after the other oral options is because insulin is so much less convenient to take. Giving injections regularly throughout the day, although isn’t too bad once you get used to it, is a hassle in comparison to the ease of an oral tablet.

Whilst it is fantastic that we have these medications to help people with Type 2 diabetes protect themselves from conditions they are prone to it is absolutely essential that attention to good lifestyle is never forgotten.

Healthy food and exercise choices should always be first and foremost in the management of Type 2 diabetes – medication is there to fill in the gaps we cannot fill ourselves.

This is the eighth post in the All About Diabetes series. You can read the last part and initial treatment options here. 

Therapeutic Guidelines Endocrinology
Australian Medicines Handbook 2012
About the author


Yolanda is a passionate medical writer who loves to help people understand how health and different treatments work. After graduating in Pharmacy in Australia, she moved to Italy to study the Mediterranean way of life and continue learning about health and medicine.

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