Most people with type 2 diabetes will at some stage have to take oral hypoglycaemia agents (OHAs) to lower their blood glucose level. These tablets are usually the first type of medication that your medical team will prescribe so that you can keep your glucose levels under control and maintain good health.
Controlling your blood glucose levels is difficult. If they get too high your risk developing heart disease or kidney problems further down the line; and if they are too low you have the more immediate risk of a hypo.
Taking the tablets that your doctor prescribes is vital to ensure that your diabetes doesn’t progress. Oral medications will:
• Help control blood glucose levels
• Help you to keep a healthy A1c
• Prevent complications
• Delay the need for insulin injections
To control your glucose levels at first, doctors will often prescribe one OHA tablet and a healthy diet with plenty of exercise. If this doesn’t work, your doctor may prescribe a combination of OHA pills and may later add insulin injections.
There are many different types of OHA tablets and they all act in different ways. They are usually first given at a lower dose and the dose is then increased in increments to get maximum benefit from the drug.
All OHAs can interact with other drugs. These interactions may reduce the effectiveness of either drug or may be harmful, so it is important to let your doctor know about any other medications, on prescription or otherwise, that you are taking.
It is common for the doctor to prescribe two or three different OHAs to be taken in combination as time progresses or diabetes worsens. They can be given with or without insulin injections.
Sulphonylureas
These were the original OHA drugs used to treat high blood glucose levels, but they are now used less often.There are a number of different sulphonylureas used in Ireland. These sulphonylureas include:
- Glibenclamide (Daonil)
- Gliclazide (Diamicron MR)
- Glimepiride (Amaryl)
- Glipizide (Minodiab and Glibenese)
Sulphonylureas act on the pancreas, increasing the amount of insulin that is secreted into the bloodstream. They are usually given with metaformin or insulin, because they do not offer great protection for the heart and they may also cause some people to gain weight.
It is important that you take these medications at the right time before meals, usually about 30 minutes, otherwise you are in danger of a hypo. You must make yourself aware of the warning symptoms when you take any medication.
Biguanide
Metaformin (Glucophage) is the only biguanide prescribed in Ireland. It is not clear exactly how metaformin works but is makes the body more sensitive to insulin and it also protects the heart. This makes it the first choice OHA for many patients.
The disadvantage of metformin is that a minority of patients get tummy upsets or nausea when they start taking it or increase the amount taken. For this reason it is best to take metaformin during a meal or just after a meal when it is less likely to cause tummy problems. A longer acting type of metaformin is taken only once a day.
Alpha-glucosidase Inhibitors
Acarbose (Glucobay) is the only alpha-glucosidase inhibitor available in Ireland. It blocks the breakdown of large sugars into glucose and delays its absorption from food. It is pretty good at reducing glucose levels after a meal but not very good at reducing overall diabetes control. Glucobay is either taken just before a meal or with the first few mouthfuls.
TZDs
TZDs are also called glitazones and there are two drugs in this class used in Ireland: rosiglitazone (Avandia) and pioglitazone (Actos). They are usually taken once a day.
TZDs make the liver and the muscles more sensitive to insulin and then they take up more glucose. This lowers blood glucose levels.
TZDs are also available in a single tablet form combined with metformin e.g. Avandamet.
DPP4 Inhibitors
DPP4 inhibitors or gliptins are a new class of OHA. They act in the intestine and limit the amount of glucose from food that goes into the bloodstream, thus lowering blood glucose levels.
Sitagliptin (Januvia) is the only oral DPP4 inhibitor available in Ireland and it is only given in a combination treatment option with either metformin or one of the TZDs. It is given once a day.
Prandial Glucose Regulators
Prandial Glucose Regulators are also a new class of oral drug. They are rapid acting and temporarily restore the post-meal insulin response that is impaired in type 2 diabetes. You take them before meals. The Prandial glucose regulators currently available in Ireland are rapiglinide (Novo norm) and nateglinide (Starlix).
Published in Diabetes Ireland Volume 6 Issue 4
APP/KOL/AC 12/02/2009