Patients receiving antidiabetic agents should consult their physicians before taking any additional prescriptions (including oral contraceptives), over-the-counter medications, nutritional supplements or herbal medications. A wide range of drugs and supplements ranging from corticosteroids to glucosamine and antidepressants to cinnamon capsules may affect glucose (blood sugar) in various ways.

Antidiabetic agents often interact well with other drugs, but there are many potential exceptions. For example, aspirin may interact with diabetes drugs including sulfonylureas, and the maker of the thiazolidinedione rosiglitazone does not recommend taking it with insulin or nitrates (a group of heart drugs) because this may increase the risk of heart problems. Patients are advised to ask their physician or pharmacist about interactions for their particular medication.

Patients should discuss alcohol consumption with their physician as alcohol can have a significant influence on medications, as well as on overall diet and health, including increased risk of hypoglycemia. Some diabetic patients are instructed by their physician not to drink any alcohol.