Is Medication Messing With Your Blood Sugar?

If you have diabetes, certain medicines and supplements may have surprising effects. Here’s what you need to know

sugar level monitor

Your blood sugar level is affected by far more than food, diabetes medicine, and insulin. Many prescription and over-the-counter medications, and even some supplements, can also make blood glucose rise or fall.

“It might be more common than people realize,” says Jasmine Gonzalvo, PharmD, BCPS, BC-ADM, C.D.E., L.D.E., a clinical associate professor at Purdue University and spokesperson for the American Association of Diabetes Educators. Many times, she explains, if a person notices a change in their blood sugar, they simply adjust their diet or insulin, not realizing that medicine could be throwing things off-kilter.

Gonzalvo suggests talking with a certified diabetes educator (CDE) or your health care provider about all the medication you’re taking or have been prescribed, including vitamins and mineral or herbal supplements. Ask if you can expect an increase or decrease in blood glucose—or no change at all. “They can help you think through the risks and benefits of using the medicine,” she says.

If the benefit outweighs the risk, she says that you may not need to adjust your dose of diabetes medicine. “There are other options to make sure your blood sugar stays healthy—like physical activity and healthy diet choices—that you can discuss with a diabetes educator,” she says. “There’s often not enough focus on the lifestyle part of the picture.”

Here’s a short list of common medications and supplements that are known to affect blood glucose.

Blood sugar boosters: Several types of medication can raise blood sugar, including cholesterol-lowering medicines (including niacin and statins); allergy, asthma, and inflammation medicines (specifically steroids, like those in some nasal sprays); and antipsychotic medicines (used to treat schizophrenia).

Beta-blockers: These high blood pressure medications can mask the signs of low blood sugar, such as a rapid heartbeat. Ask your C.D.E., pharmacist, or doctor if you should take special precautions when on these medications. Also be sure to check your blood sugar often when you start a beta-blocker.

Antibiotics: Certain antibiotics can impact blood sugar—and so can fighting an illness or infection. “If you’re sick, continue to take your diabetes medication, including insulin, and check your blood sugar frequently,” says Gonzalvo.

Syrups: Cough medicine and other syrups (such as liquid pain relievers) often contain sugar. Ask your pharmacist if there’s a sugar-free formula. Many syrups also contain alcohol, although there’s typically not enough alcohol to have much of an effect on blood sugar. Still, you’re smart to limit your intake of alcoholic beverages, as they can cause a dangerous drop in your blood sugar levels.

Cinnamon supplements: When taken as a supplement, this kitchen spice can lower blood sugar—but only a modest degree. Unless you’re using several tablespoons in a serving of food, cinnamon is not likely to cause a problem if you’re using it for cooking or baking.