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Prednisone and Diabetes: A Life-Threatening Glucose Spike

Prednisone saves lives! It restored my hearing when I went deaf. But prednisone has lots of side effects. Prednisone and diabetes is real.

We have described prednisone as a “Deal with the Devil.” That’s because this drug is the classic double-edged sword. It can save lives and make life worth living for some people. For others, though, it can cause serious side effects including edema, insomnia, irritability, hypertension, glaucoma, cataracts, ulcers, blood clots, weakened bones and osteoporosis. There is also an association between prednisone and diabetes which in some cases can be life threatening. Here is one such report.

Where Was the Warning About Prednisone and Diabetes?

Q. Three years ago, I developed a lung infection. The pulmonologist prescribed a short course of prednisone without any mention of side effects, which I promptly developed. Since I couldn’t get any answers from him or my primary care physician, I stopped taking the drug.

Last year the infection came back. The symptoms had me worried about a heart attack. The emergency room and the pulmonologist put me on an aggressive tapered course of prednisone, but didn’t talk about side effects. I experienced dry mouth, frequent urination, blurry vision, dizziness, constipation and mouth sores.

After 15 days of this, I went back to the emergency department. They apologized for not telling me that the prednisone would raise my blood sugar, which was at 605 when they checked.

They administered insulin and showed me how to use it for the rest of the prednisone course. Let others know that prednisone can definitely raise blood sugar!

Was There a Connection Between Prednisone and Diabetes?

A. Your blood sugar was critically high. A normal fasting blood glucose level is less than 100. Two hours after eating the level should be under 140. At 605 you were way into the danger zone. Thank goodness you received emergency treatment.

A Diabetes Educator Takes Physicians & Pharmacists to Task!

Q. As a nutritionist and diabetes educator, I find it frustrating that doctors and pharmacists do not inform patients of the side effects of prednisone, especially raising blood glucose. Several of my clients have successfully maintained normal blood glucose while taking prednisone by following individualized guidelines to avoid sweet beverages and juice, drinking water instead.

Limiting carbohydrates, eating adequate protein, and taking advantage of the energy boost prednisone offers by exercising (with the doctor’s okay) all help. Many may be able to get around this side effect of prednisone with good education, but they should be informed that they need to pay attention and encouraged to monitor blood glucose.

A. Thank you for reminding us that many medications can raise blood sugar. Corticosteroids like prednisone are especially problematic.

You can learn more about other medications that may do this as well as dietary strategies to help keep blood glucose under control in our eGuide to Preventing & Treating Diabetes.

Diabetic Hyperosmolar Syndrome:

Here is what the Mayo Clinic says about blood sugar that tops 600 milligrams per deciliter (mg/dL):

“Severely high blood sugar turns your blood thick and syrupy. The excess sugar passes from your blood into your urine, which triggers a filtering process that draws tremendous amounts of fluid from your body. Left untreated, this can lead to life-threatening dehydration and a diabetic coma.”

Prednisone and Diabetes:

You are correct that prednisone and other corticosteroids can raise blood sugar. Even inhaled steroids can have this effect (Diabetes, Obesity & Metabolism, online April 1, 2020).

A short course of corticosteroids may raise blood sugar levels, but once the steroid is tapered, metabolism can return to normal. Some people have to take drugs like prednisone for months or years, though. Even after the medication is stopped, they may be left with type 2 diabetes.

Anyone taking steroids should be alert for side effects such as frequent urination and a thirst that won’t quit. Then there is the dry mouth that water can’t fix. Be alert for fatigue and exhaustion. Another concern: visual disturbances and/or blurred vision.

Other Stories of Prednisone and Diabetes:

Joe also experienced a critical blood sugar level after taking prednisone:

“As a child I was diagnosed with an autoimmune condition called dermatomyositis. Growing up I had periodic treatment with prednisone.

“When I was 27 I was on a 2 week course of prednisone . Then my doctor called me himself and told me to go straight to the hospital since my blood glucose was 740. I have not been on prednisone since.

“As I got older I had minimal problems with the dermatomyositis. But in the last 5 years my diabetes has been out of control and considered very brittle. My doctor has had to change my insulin type four times in the last nine months. I feel most of my problems are the result of my long time use of prednisone.”

Cheri had her type 2 diabetes go critical after a big dose of prednisone!

“I had to go to the ER today for a severe allergic reaction. They hooked me up to the IV within 5 minutes of me walking in (yep, that bad) and they gave me a few meds into the IV including 120 mg of prednisone. The doctor sent me home with a prescription of prednisone (20 mg. tablets). I was to take 3 pills once a day for 5 days. He did say it would affect my type 2 diabetes, but WOW he never said it would go to 499 tonight!”

Miriam shares her experience with prednisone and diabetes:

“About 14 years ago, I was in the hospital with pneumonia and was not responding to their breathing treatments. I was given prednisone without being asked or told.

“When I got out of the hospital and saw my medical provider a few days later, I wound up with type 2 diabetes and a sugar count of 650. Then I was put on several pills, none of which worked to lower my numbers. Then I received two forms of insulin which I would need to take daily for the rest of my life.”

The People’s Pharmacy Perspective:

Dozens of other drugs, including statins and diuretics, can also interfere with blood glucose control. You can learn more about these in our eGuide to Preventing & Treating Diabetes.

We also discuss nondrug approaches such as cinnamon, vinegar, curcumin and coffee or supplements like selenium, bitter melon, fenugreek or nopal cactus. You will find it in the Health eGuides section.

Physicians should alert patients to the possibility that a medication could raise blood glucose when they prescribe it. There is a clear connection between prednisone and diabetes.

As mentioned above, statins can also raise blood sugar (European Journal of Pharmacology, May 15, 2023). This is an inconvenient truth for cardiologists, especially since they recommend that people with diabetes must take statins. But raising blood glucose also has cardiovascular risks. Do you begin to sense a Catch 22 here?

No one should ever discontinue prednisone suddenly! If it becomes necessary to stop this corticosteroid, it should only be done under medical supervision. A gradual tapering is essential to prevent other serious complications.

Here is an article you may find interesting:

Prednisone Side Effects: Deal With The Devil?
Prednisone is a valuable medication for many serious conditions, but prednisone side effects can be serious, including sepsis and psychological reactions.

Share your own experience with prednisone or other corticosteroids in the comment section below.

If you think this information might help someone you know, please share it via email, Facebook or Twitter by clicking on one of those icons at the top of this page. Thank you for supporting our work by spreading the word.

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About the Author
Joe Graedon is a pharmacologist who has dedicated his career to making drug information understandable to consumers. His best-selling book, The People’s Pharmacy, was published in 1976 and led to a syndicated newspaper column, syndicated public radio show and web site. In 2006, Long Island University awarded him an honorary doctorate as “one of the country's leading drug experts for the consumer.”.
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  • Alvarez-Jimenez, L., et al, "Effects of statin therapy on glycemic control and insulin resistance: A systematic review and meta-analysis," European Journal of Pharmacology, May 15, 2023, doi: 10.1016/j.ejphar.2023.175672
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