The Dangers of Diabetes Medication on the Heart and Blood Sugar

Varuna Srinivasan, MBBS MPH, Jared Hirschfield, National Center for Health Research

Sulfonylureas are a popular medication for the treatment of type 2 diabetes. These drugs increase the levels of insulin produced and stored by the pancreas. Older sulfonylureas, such as Tol-Tab and Diabinese, are no longer in use due to serious and potentially deadly side effects, but newer sulfonylureas (Diamicron, Glucotrol, Diabeta and Amaryl) are frequently prescribed, usually in combination with other common diabetes drugs, such as Glucophage (metformin), thiazolidinediones (TZDs) and injectable insulin.[1]

blood sugar meter

Nevertheless, sulfonylureas can cause many harmful side effects, such as low blood sugar and heart problems. After years of uncertainty, there is growing evidence that patients taking sulfonylureas are more likely to have a heart attack or die from heart issues than other diabetes patients on metformin alone.[2,3]

Some types of sulfonylureas have more side effects than others, however.[3] For example, patients taking Diabeta are more likely to die than patients taking other sulfonylureas.[4]  

Insulin works to reduce your blood sugar level. If your insulin levels are too high, your blood sugar could drop below a healthy level, causing a dangerous condition called hypoglycemia. Another study published in Diabetes Care, the research journal of the American Diabetes Association, found that Diabeta is 83% more likely to cause hypoglycemia than other sulfonylureas or other diabetes medications.[5]

The high risk of death caused by sulfonylureas was first explained in a report in the 1970’s. Since then, the FDA has required manufacturers to include a black-box warning on all sulfonylurea drugs.[6] Black-box warnings are the strictest warnings put on drug labeling by the FDA and are designed to call patients’ attention to serious or life-threatening risks.[7]

Bottom line

Research is needed to evaluate which combinations of drugs are safest for the management of type 2 diabetes. However, with many safer drugs on the market, why take sulfonylureas as standalone treatment? Be sure to speak with your doctor if he or she recommends sulfonylureas for you.

Remember that all diabetes medications have some level of risk. Read your medication’s warning labels or research the risks on and contact if you have any further questions.


[1] Sola, D., Rossi, L., Schianca, G. P. C., Maffioli, P., Bigliocca, M., Mella, R., … Derosa, G. (2015). Sulfonylureas and their use in clinical practice. Archives of Medical Science : AMS, 11(4), 840–848.

[2] Douros, A., Dell’Aniello, S., Yu, O. H. Y., Filion, K. B., Azoulay, L., & Suissa, S. (2018). Sulfonylureas as second line drugs in type 2 diabetes and the risk of cardiovascular and hypoglycaemic events: Population based cohort study. Bmj, 362, k2693. doi:10.1136/bmj.k2693

[3] C. Ll. Morgan J. Mukherjee S. JenkinsJones S. E. Holden C. J. Currie. (2014). Association between firstline monotherapy with sulphonylurea versus metformin and risk of allcause mortality and cardiovascular events: A retrospective, observational study*. Journal of Pharmacology and Therapeutics, 16(10), 957-962. doi://

[4] Evans, J., Ogston, S., Emslie-Smith, A., & Morris, A. (2006). Risk of mortality and adverse cardiovascular outcomes in type 2 diabetes: A comparison of patients treated with sulfonylureas and metformin. Diabetologia, 49(5), 930-936. doi:10.1007/s00125-006-0176-9

[5] Azim S Gangji, Tali Cukierman, Hertzel C Gerstein, Charles H Goldsmith, & Catherine M Clase. (2007). A systematic review and meta-analysis of hypoglycemia and cardiovascular events: A comparison of glyburide with other secretagogues and with insulin. Diabetes Care, 30(2), 389-394. doi:10.2337/dc06-1789

[6] Genuth, S. (2015). Should sulfonylureas remain an acceptable first-line add-on to metformin therapy in patients with type 2 diabetes? no, it’s time to move on. Diabetes Care, 38(1), 170-175. doi:10.2337/dc14-0565.

[7] U.S. Food and Drug Administration. “A Guide to Drug Safety Terms at FDA.” November 2012.