Have High Blood Sugar? It Could Be a Side Effect of These Medications

Hyperglycemia, or a high level of blood glucose (blood sugar), is common in people with diabetes. Having high blood sugar can be harmful, and it’s why people with diabetes need to pay attention to how they eat and exercise. It’s also why they may need to take regular medication when diet and exercise aren’t enough. 

Usually the body is really good at keeping blood glucose levels within safe limits. It’s very unusual for otherwise healthy people to have blood glucose levels that are too high or too low. 

But certain drugs can raise blood sugar levels, including some very common ones. Sometimes, the increase in blood sugar is temporary and goes away when you stop taking the medication. But medications can also increase the risk of developing Type 2 diabetes in people who don’t have diabetes yet. 

1. Corticosteroids

Steroids, like prednisone, are used to treat inflammation in lots of conditions, including rheumatoid arthritis, asthma, chronic obstructive pulmonary disease (COPD), and inflammatory bowel disease. 

Steroids — taken either as pills or injection — can raise blood sugar levels while you’re taking them. (This is much less likely with inhaled steroids.) This can be a problem in people who already have diabetes and those who don’t have diabetes. 

Increased blood sugar is more likely if you take higher doses of steroids over the long term. It’s also more common in people with risk factors for diabetes. This includes: 

• People with a family history of diabetes

• Older adults

• People with prediabetes or previous diabetes in pregnancy

Glucose levels typically go back to baseline when you stop taking steroids or when you take a lower dose. 

2. Beta blockers

Beta blockers are medications that treat heart problems, like irregular heart rate and high blood pressure. 

Examples of beta blockers include: 

• Atenolol

• Metoprolol

• Propranolol

These beta blockers can increase blood glucose in people with diabetes and cause new Type 2 diabetes in people who didn’t have it before. This seems to happen because the beta blockers reduce how much insulin the pancreas makes. 

But not all beta blockers do this. Carvedilol (Coreg) and nebivolol (Bystolic) don’t affect blood sugar levels or cause diabetes. 

3. Hydrochlorothiazide and metolazone

Some other blood pressure medications, such as thiazide diuretics and thiazide-like diuretics, can have a similar effect. Like beta blockers, hydrochlorothiazide (HCTZ) and metolazone can increase blood sugar levels. They can also cause new Type 2 diabetes in as little as 9 to 18 weeks. 

This seems to be more common the longer someone takes the medication. This also happens more often in people who have a higher risk of Type 2 diabetes. It’s not clear exactly how it happens. But it’s likely to be related to insulin production and how well the body responds to that insulin. 

4. Statins

There may be a link between regular use of statins — medications that treat high cholesterol — and a small increase in glucose levels in certain people. Other studies have suggested a slight increase in hemoglobin A1C (HbA1C or A1C) levels, which are your average blood sugar levels over about 3 months. 

Statins seem to cause cells in the body to become resistant to insulin, the hormone that helps move glucose out of the blood and into cells. 

But there are mixed results. So, more research is needed to better understand how statins affect glucose management.

The risk is higher in people who take larger doses of statins, like 40 mg to 80 mg of atorvastatin (Lipitor) or 20 mg to 40 mg of rosuvastatin (Crestor) and simvastatin. 

The risk is also higher for: 

• Older adults

• People with risk factors for diabetes

• People who already have prediabetes

For most people, especially those who already have diabetes, the benefit of taking statins far outweighs the small increased risk of Type 2 diabetes. 

5. Quinolone antibiotics

One class of antibiotics — quinolones — has been linked to both high and low blood sugar levels in people with Type 2 diabetes. This is most common with the quinolone antibiotic gatifloxacin. 

It’s probably best to avoid quinolone antibiotics if you’re older than 65 and have other risk factors for Type 2 diabetes. Other quinolones, like ciprofloxacin and moxifloxacin, don’t seem to have this effect. 

6. Leuprolide and goserelin

Many men with prostate cancer get androgen deprivation therapy with medications like: 

• Lupron (leuprolide)

• Zoladex (goserelin)

• Trelstar (triptorelin)

• Firmagon (degarelix)

But the use of these medications has been linked to a significantly increased risk of developing Type 2 diabetes. The risk comes from an increase in body fat along with: 

• A decrease in muscle mass

• A change in blood fat and cholesterol levels

• Insulin resistance 

7. Newer antipsychotics

Newer antipsychotics, like clozapine and olanzapine, cause an increase in blood sugar levels in people with diabetes, and they increase the risk of developing Type 2 diabetes. This is most likely because these medications cause weight gain. But this link hasn’t been seen with all antipsychotics. 

Risperidone (Risperdal) and quetiapine (Seroquel) cause an increase in body weight. But studies are mixed on whether these medications are linked to an increase in diabetes. 

8. Protease inhibitors to treat HIV

Protease inhibitors are one of six major classes of antiretroviral therapies for people living with HIV. And they have a long history of being linked to: 

• Weight gain

• Metabolic syndrome

• Raised blood sugar levels

• New diabetes diagnosis

In people with other risk factors for diabetes, it’s probably a good idea to avoid protease inhibitor medications like:

• Atazanavir

• Darunavir

• Ritonavir

The good news is that there are now many alternatives to protease inhibitors. Other classes of medications don’t cause diabetes and high blood sugar levels, including:

• Integrase strand transfer inhibitors (INSTIs): raltegravir, elvitegravir, dolutegravir, bictegravir

• Non-nucleoside reverse transcriptase inhibitors (NNRTI): efavirenz, nevirapine

9. Immunosuppressants

Calcineurin inhibitor medications are commonly used after organ transplants. Examples of these are:

• Cyclosporine

• Sirolimus

• Tacrolimus

These medications have been linked to an increased risk of diabetes, especially in older adults and those who also take steroids. As many as 1 in 4 people develop diabetes for the first time during the 3 years after a kidney transplant. 

Should you avoid these medications if you have diabetes?

If you have diabetes, taking medications that affect blood sugar levels can make it harder to stay within your target range. Your healthcare team can help you manage this. But, before starting new medications, it’s always worth reminding your prescriber and pharmacist that you have diabetes. 

If the treatment is necessary, you may need to take more of your diabetes medication during treatment. 

When to talk to a healthcare professional

It’s never too early to talk to your healthcare team about high blood sugar if you’re taking any of these medications. By being aware of the risk, you’ll be able to take steps early to reverse high blood sugar caused by medications.

If you’re at risk for Type 2 diabetes, a healthcare professional can order regular blood glucose testing to make sure that the treatment stays safe for you. 

If your blood sugar levels rise, you may need to make adjustments to your medications. This may mean taking a lower dose or switching to a different medication. In some cases, you may need treatment for high blood glucose. 

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Written by:

Jewels Doskicz, RN, BA

Jewels Doskicz, RN, is an Arizona-based registered nurse with more than 20 years of hospital-wide clinical nursing experience. She has spent over a decade in medical writing and editing, with a focus on diabetes and autoimmune disease.

Edited by:

Alex Eastman, PhD, RN

Alex Eastman, PhD, RN, is a California-based registered nurse and staff medical editor at GoodRx, where he focuses on clinical updates and Latino health.

Reviewed by:

Farzon A. Nahvi, MD

Farzon Nahvi, MD, is an emergency medicine physician and author of “Code Gray: Death, Life, and Uncertainty in the ER.” He works at Concord Hospital in Concord, New Hampshire, and teaches at the Geisel School of Medicine at Dartmouth.

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