Sometimes, despite your best efforts, your blood sugars may seem to get out of control. It happens to everyone living with diabetes, and there could be a number of reasons why it occurs.

You may be getting sick, your body chemistry may be changing, your exercise habits may be different, but maybe it’s that new medication you’re taking. The truth is that certain medications have the potential to cause some unexpected effects and possibly influence your diabetes control. And as we age, medications often become necessary as high blood pressure, high cholesterol, and other medical issues begin to affect our health.

Here is a brief description of the different interactions that certain drugs can have and how they may influence your blood glucose levels:

  • Statins are a fairly common group of medications used for treating high cholesterol. They are quite effective at bringing down cholesterol, but can also have some side effects, especially if they are not taken correctly. When you got your first prescription of a statin medication, your pharmacist may have cautioned you to let your doctor know if you experienced muscle aches. This is because muscle damage, although rare, can happen in certain patients on statins. It is especially true if statin drugs reach a higher than normal level in your bloodstream. Other medications, including certain antibiotics such as clarithromycin, can cause statin drugs to not be metabolized properly, causing blood levels of statins to be higher than normal. This can also happen with grapefruit juice in some cases because grapefruit juice contains an enzyme that can prevent the breakdown of certain medications.
  • Certain high blood pressure medications can also be affected by other medications or by food. Captopril and valsartan, common drugs used for hypertension, need to be taken on an empty stomach, ideally one hour before a meal or two hours after eating. This is because food can decrease the blood levels of these drugs, rendering them less effective. In fact, as much as a 50 percent decrease in blood levels of valsartan can be seen if it is taken with food.[1]
  • Other medications can cause blood sugars to increase as a side effect which is not usually a significant problem for people without diabetes, but if you have diabetes, this can be dangerous. Two of the main drug categories that affect blood sugar control are oral steroids such as prednisone and some anti-psychotic medications such as risperidone. If you have diabetes and need to take medications in one of these two categories, your healthcare team will help you address any unforeseen blood sugar spikes with possible medication changes. You will also most likely need to check your blood sugars more frequently than normal if you’re taking these drugs.
  • Another thing to be careful of is taking dietary supplements without letting your healthcare team know in case there are any precautions you may need to take. For example, St. John’s Wort can interact with prescription antidepressants, making them more potent and potentially more toxic. Ginseng, which many people take for energy can interact with warfarin, a blood thinner, and can potentially interfere with warfarin’s ability to prevent clotting.[2]

The key takeaway here is to make sure your healthcare team is aware of all the medications you take, even over the counter medications. Don’t overlook anything; even acetaminophen, such as Tylenol, can be a problem for some people. If you use a CGM, for example, acetaminophen can cause blood sugar readings to be less accurate.

If you have any questions regarding safe medication usage, never hesitate to ask your pharmacist, doctor, or medical team for help!

About Susan Sloane
Susan B. Sloane, BS, RPh, CDE, has been a registered pharmacist for more than 29 years and a Certified Diabetes Educator for most of her career. Her two sons were diagnosed with diabetes, and since then, she has been dedicated to promoting wellness and optimal outcomes as a patient advocate, information expert, educator, and corporate partner.

[1] Unger T, Kaschina E: Drug interactions with angiotensin-receptor blockers: comparison with other antihypertensives. Drug Saf 26: 707 –720, 200

[2] https://www.webmd.com/ heart-disease/news/20040706 /ginseng-no-no-for-patients-on-coumadin

DAR -0069 RevA 06/2019