Medications That Raise Blood Sugar

Type 2 diabetes isn't usually a party of one. People with diabetes have a higher risk of developing other health conditions, such as high blood pressure, gout, and high cholesterol, which often require additional medication.

“These meds — such as beta-blockers, corticosteroids, and statins — can be lifesaving, but they can also come with side effects, such as raising blood sugar,” says Raj Singh MD, a board-certified primary care doctor in Las Vegas, Nevada.

"It really depends on the half-life of that medication, meaning how long it stays in your system once it is stopped," says Deena Adimoolam, MD, a specialist in endocrinology, diabetes, and metabolism in New York City. "Some medications have a long duration of action, so their impact on blood sugar will be longer."

But that doesn’t necessarily mean you shouldn’t take a medication that can raise your blood sugar. "When used correctly and in close consultation with a physician, the side effects of these medications can be significantly reduced," Dr. Singh says.

Here, we’ll look at some of the most common meds affecting blood sugar control and give guidance on the best ways to manage your blood sugar.

Corticosteroids like prednisone and dexamethasone act like the hormones your adrenal glands make. Corticosteroids treat many inflammatory conditions.

"We often prescribe these drugs to tone down swelling and calm the immune system when dealing with stuff like gout flares, asthma, arthritis, or autoimmune problems," Singh says. “But a big downside to corticosteroids is they can bump up your blood sugar. The spike in blood sugar is dose related, and a higher dose equates to increased blood sugar levels.”

This spike in blood sugar from corticosteroids happens for two reasons. First, corticosteroids kick-start the liver into making extra glucose using a pathway called gluconeogenesis. "This pathway is the method by which the liver turns proteins and amino acids into glucose, and this bump in glucose production leads to increased sugar in the blood," Singh says. The second reason, he adds, is that "corticosteroids can make your body less sensitive to insulin, resulting in higher blood sugar levels."

Steroids begin to raise your blood sugar within six to eight hours of taking them, Singh explains. “Eating fewer calories and being more physically active can help balance out the blood sugar spike. But if you take insulin, you may need to work with your doctor to increase your insulin dosage while you're on corticosteroids,” he says. Some people who did not previously require insulin may need it for the first time while on corticosteroids.

Beta-blockers are a large class of drugs that lower blood pressure and treat a variety of other conditions, including irregular heartbeat and anxiety. But they can also raise your blood sugar levels.

"Beta-blockers can block the effects of insulin and, in some cases, prevent the release of insulin from the pancreas," Singh says. "This can cause elevated blood sugar levels in people with preexisting diabetes, but the effect on blood sugar is minimal to nonexistent in people without preexisting diabetes."

Some types of beta-blockers have less of an effect on blood glucose than others. "Older beta-blockers such as atenolol and metoprolol are much more likely to cause elevated blood sugar levels, whereas new generation beta-blockers such as carvedilol tend to have a protective effect and may not cause hyperglycemia," Singh says.

It’s important to note that beta-blockers can mask tachycardia (fast heartbeat) associated with hypoglycemia (low blood sugar).

"The exact mechanism is not clear, but it appears that statins may render insulin less effective and also block insulin release from the pancreas in sensitive individuals," Singh says. “Certain statins, such as simvastatin (Zocor), seem to cause more hyperglycemia when compared with pravastatin and atorvastatin.”

If you have prediabetes or a high risk of developing diabetes, Singh doesn't recommend taking simvastatin. Ask your doctor to switch to pravastatin or atorvastatin instead. These statins have a lower risk of hyperglycemia.

Certain antipsychotic drugs, which treat schizophrenia and other mental illnesses, can increase your blood sugar levels. "Atypical antipsychotics may have a direct impact on glucose and fat metabolism, leading to higher levels of sugar," Dr. Adimoolam says.

If you're on an antipsychotic, monitor your blood sugar closely. "If there is a change to your blood sugar levels, you can work with your doctor to switch to a different antipsychotic or change your diabetes medications, " Adimoolam says.

Diuretics, also called water pills, cause you to urinate more frequently because they're meant to make you flush out fluid. Doctors usually prescribe them to people with high blood pressure or people with too much fluid in their body. “Specifically, the class of diuretics called thiazides is associated with high blood sugar levels,” Adimoolam says.

"The mechanism for why this happens is uncertain, but it may be related to potassium shifts, leading to a decrease in insulin production from the pancreas," she says, adding that this increase in blood sugar is very rare.

If you're on diuretics, you'll want to closely monitor your blood sugar levels. “If there's a change in your blood sugar levels, talk to your doctor about stopping thiazide and replacing it with alternative blood pressure medication, or continue the thiazide and adjust your insulin dosage,” Adimoolam says.