Diabetes Forecast

Over-the-Counter Meds that Raise Blood Glucose

From cough syrup to decongestants, here are the over-the-counter drugs that may affect your blood glucose

By Allison Tsai , , ,
cough syrup being poured into dosing cup


When you feel a tickle in your throat or the telltale malaise of an impending cold, it may be time to take a trip to the pharmacy. But what, if any, products should you avoid?

When you are fighting a cold, your blood glucose may already be elevated, says Izabela Collier, BS Pharm, PharmD, CDE, clinical assistant professor of pharmacy practice at Western New England University. Treating with medications that have added sugar may be a double whammy.

If you’re unsure about the effect of a specific medication you’ve taken, monitor your blood glucose. “Whenever in doubt when taking a new medication, check your sugar,” says Alan Garber, MD, PhD, professor of medicine in the Division of Diabetes, Endocrinology, and Metabolism at Baylor College of Medicine.

  • Pseudoephedrine—This decongestant found in some cold and flu medications can raise both blood glucose and blood pressure.
  • Cough Syrup—The big question is: regular or sugar free? While Collier suggests always using the sugar-free variety, Garber says it may not make a big difference unless your numbers are already high. If your illness is causing your blood glucose to rise, treating with sugary syrup will just make matters worse. But if your glucose is within your target range despite your sickness, taking regular cough syrup is probably not going to have major consequences, he says.
  • Caffeine—Products with adrenergic (caffeine-like) effects are best avoided, says Garber. They can cause an accelerated heart rate, increased blood pressure, and heightened anxiety or nervousness. These products include everything from pseudoephedrine to coffee, tea, and soda.

DON'T FORGET: Never change your diabetes medications when you’re sick without checking with your care provider. You may need to reduce sulfonylureas (such as glimepiride), meglitinides (such as repaglinide), and rapid-acting insulin if you can’t eat. But you still need basal insulin. “Even though your body is fighting and you may not be eating, you still need the maintenance medications,” Collier says. To correct high blood glucose that results from the bodily stress of illness, you may need to use rapid-acting insulin up to several times per day.

Find out how some over-the-counter medications affect blood glucose.



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