Apart from the medicines you take to control your diabetes — insulin and/or oral hypoglycaemic tablets — you may need to take medicines to treat other conditions. Some of these medicines can affect your blood sugar levels and alter your usual blood glucose control.
In addition, some medicines may worsen the complications of diabetes, such as kidney disease.
Keep your doctor informed
It is important to always tell any doctor who is treating you that you have diabetes.
Also tell them the names and doses of all the medicines you are currently taking, including:
- your diabetes medicines;
- other prescription medicines (including ointments, eye drops and medicines you take only when needed);
- over-the-counter preparations from your pharmacist or supermarket; and
- herbs, supplements and complementary medicines.
Your doctor will then be able to prescribe medicines for you with your diabetes control in mind.
Also, if you use complementary medicines, make sure your complementary healthcare practitioner knows:
- that you have diabetes;
- whether your diabetes has affected any vital organs such as your kidneys; and
- which diabetes medicines you are taking.
Medicines that raise blood glucose levels
Some medicines may increase your blood glucose levels. For example,
- corticosteroids (usually prescribed to treat inflammation in the body as may occur in arthritis, asthma or other lung problems);
- some antipsychotic medicines;
- some diuretics (‘fluid’ tablets); and
- some over-the-counter medicines that are in syrup form and contain a high level of sugar.
Medicines that lower blood glucose levels
Some medicines may decrease your blood glucose levels by, for example, increasing your sensitivity to insulin or enhancing the glucose-lowering effect of sulphonylurea tablets prescribed to treat diabetes.
Medicines that may lower blood glucose levels include:
- certain antidepressants;
- certain antibiotics;
- quinine (an antimalarial); and
- fenugreek (a type of herbal supplement).
Tips to help keep your diabetes well-controlled
- Before you take a new medicine, including a complementary therapy, ask your doctor or pharmacist what effect it might have on your diabetes.
- When starting a new medicine that might affect control of your diabetes, check your blood glucose levels more often.
- If you notice that a new medicine is causing an unexpected change in your blood glucose levels, or a change in your blood glucose levels that is not responding to adjusting your diabetes medication, talk to your doctor.
- If you have any complications of diabetes, such as kidney problems or blood supply problems in the legs, talk to your doctor about how your new medicine might affect these conditions.
- For medicines that have the unwanted side-effect of affecting blood glucose levels, there may be another similar medicine that will still treat you effectively, but will not affect your diabetic control — always check with your doctor or pharmacist.
- If you are purchasing a medicine that is in syrup form, ask the pharmacist if a ‘sugar free’ option is available.
- Knowing how a new medicine might affect your blood glucose control allows you to prepare yourself for a possible change in your usual blood glucose levels and for a possible need to adjust your insulin dose or other diabetes medication.