Medicines that affect blood glucose levels in type 1 diabetes

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 your diabetes medicine (injected insulin) and affect your blood glucose levels. This may mean that your health professional will need to adjust your dose of insulin, or make changes to your other medicines.

Medicines that increase blood glucose levels

The table below lists some of the medicines that are known to increase blood glucose levels.

Medicine
What is it used for?
Adrenaline* Can be used as an emergency treatment for severe allergic reactions; as part of its actions on the body, it increases blood glucose levels
Asthma medicines (e.g. injected salbutamol*)
Prevent asthma attacks and relieve asthma and chronic obstructive pulmonary disease symptoms; an increase in blood glucose is not common with inhaled asthma medicines but may occur with high doses or if injected
Antipsychotic and antidepressant medicines (some) Used to treat depression, mental illness or psychotic disorders; some antipsychotic and antidepressant medicines may increase blood glucose levels
Baclofen* Used to relax muscles in people with multiple sclerosis or spinal injuries; baclofen increases blood glucose levels
Cyclosporin,* sirolimus* and tacrolimus* Used to prevent rejection of kidney transplants; these medicines commonly increase blood glucose levels
Nicotinic acid* Used to lower cholesterol and fats (triglycerides) in the blood; this can sometimes cause blood glucose levels to increase
Isotretinoin* Used to treat severe acne, but can increase blood glucose levels
Phenytoin* Used to prevent seizures in people with epilepsy; increased blood glucose is a rare side effect of this medicine
Corticosteroids with glucocorticoid effects (not fludrocortisones*) Glucocorticoids are used for people with severe asthma, organ transplants and cystic fibrosis; they increase glucose production by the liver
Thiazide diuretics Used to treat high blood pressure and fluid build-up (oedema); these may increase blood glucose levels but their effect on blood glucose is very small at low doses

Note: The medicines labelled with an asterisk (*) are all active ingredients. The active ingredient is the chemical in the medicine that makes it work. Most medicines have two names: the active ingredient and the brand name. The brand name is the name given to the medicine by its manufacturer. As there are often many different brands of one medicine, we have only listed the active ingredients of the medicines here. To find out more, read our information about active ingredients and brand names.

Medicines that decrease blood glucose levels

The table below lists some of the medicines that are known to decrease blood glucose levels to some extent as a side effect. They are not prescribed for this purpose.

Medicine What is it used for?
Alcohol Excessive alcohol use stops the liver from producing and releasing glucose into the blood
Aspirin* (analgesic doses) Used to relieve pain or inflammation; aspirin decreases blood glucose levels
Beta blockers Used to decrease heart rate, high blood pressure (hypertension), heart failure, angina (chest pain), and migraines; beta blockers can mask the symptoms of hypoglycaemia
Non-selective monoamine oxidase inhibitors Used to treat depression when other treatments have not worked; these medicines decrease blood glucose levels
Quinine* Used to prevent and treat malaria infections; quinine decreases blood glucose levels
Trimethoprim with sulfamethoxazole* This combination of antibiotics is used to treat various bacterial infections, and a type of pneumonia caused by a yeast-like fungus (Pneumocystis pneumonia); hypoglycaemia is rare but can be caused by this combination

Note: The medicines labelled with an asterisk (*) are all active ingredients. The active ingredient is the chemical in the medicine that makes it work. Most medicines have two names: the active ingredient and the brand name. The brand name is the name given to the medicine by its manufacturer. As there are often many different brands of one medicine, we have only listed the active ingredients of the medicines here. To find out more, read our information about active ingredients and brand names.

Phone for medicines information

Call NPS Medicines Line on 1300 MEDICINE (1300 633 424) to get information about your prescription, over-the-counter and complementary medicines from a pharmacist.

References
  • Craig ME, Twigg SM, Donaghue KC, et al for the Australian Type 1 Diabetes Guidelines Expert Advisory Group. National evidence-based clinical care guidelines for type 1 diabetes in children, adolescents and adults. Canberra: Australian Government Department of Health and Ageing, 2011. www.diabetessociety.com.au/downloads/Type1guidelines14Nov2011.pdf (accessed 15 November 2011).
  • Rossi S, ed. eAMH [online]. Adelaide: Australian Medicines Handbook, July 2012.
  • Sweetman S, ed. Martindale: The complete drug reference [online]. London: Pharmaceutical Press. www.medicinescomplete.com/mc/martindale/current/ (accessed 18 October 2011).
  • Baxter K, ed. Stockley's drug interactions: A source book of interactions, their mechanisms, clinical importance and management. 9th edn. London: Pharmaceutical Press, May 2010. www.medicinescomplete.com/mc/stockley/current/ (accessed 18 October 2011).
  • The relevant consumer medicine information and product information have been consulted for every medicine discussed.