Drugs That Can Raise Blood Glucose Levels

Abnormally high blood glucose (hyperglycemia), defined as at least 126 milligrams per deciliter on two separate tests while fasting, is a key indicator of diabetes mellitus,[1] which can lead to serious health complications if not managed properly. Many drugs can cause hyperglycemia by various mechanisms, including reducing insulin synthesis or tissue sensitivity to insulin, a condition that is called drug-induced hyperglycemia.

Drug-induced hyperglycemia can occur in individuals with previously normal blood glucose levels (a state that is usually reversible). It also can exacerbate hyperglycemia in individuals with pre-existing diabetes.[2]

Below are some of the main drugs that can cause drug-induced hyperglycemia. Learn about these drugs so you can protect yourself and your loved ones from this adverse effect.

Antibiotics

Fluoroquinolones, a group of broad-spectrum antibiotics that includes ciprofloxacin (CIPRO and generics), levofloxacin (generics only) and ofloxacin (generics only), are the only class of antibiotics that is consistently linked to drug-induced hyperglycemia in some patients.[3] Usually, it is recommended to discontinue these drugs if signs or symptoms of glucose disturbances develop during their use.

In 2006 Public Citizen’s Health Research Group petitioned the Food and Drug Administration (FDA) to ban the fluoroquinolone drug gatifloxacin (TEQUIN) because it causes both hyperglycemia and hypoglycemia (low blood glucose levels) more than any other fluoroquinolone. In 2008 the FDA determined that gatifloxacin was withdrawn from the U.S. market for reasons of safety or effectiveness.[4]

Antiepileptics

The commonly used epilepsy drug phenytoin (DILANTIN, PHENYTEK and generics) can cause hyperglycemia because it inhibits the release of insulin.[5] In addition, the antiepileptic and mood stabilizer drug valproic acid (generics only) is linked to hyperglycemia in both adults and children.[6] For example, one study showed that 45% of children with epilepsy who received valproic acid monotherapy had evidence of increased fasting glucose or impaired glucose tolerance within two years of starting the drug.[7]

Antipsychotics

Hyperglycemia may occur occasionally with the use of first-generation (typical) antipsychotics, such as chlorpromazine (generics only).[8]

However, the risk of hyperglycemia is significantly higher with second-generation (atypical) antipsychotics, especially clozapine (CLOZARIL, VERSACLOZ and generics) and olanzapine (ZYPREXA and generics). These drugs also generally increase the risk of metabolic abnormalities such as weight gain.

Beta-blockers

Beta-blockers — such as propranolol (HEMANGEOL, INDERAL LA, INNOPRAN XL and generics), metoprolol (KAPSPARGO SPRINKLE, LOPRESSOR, TOPROL-XL and generics) and atenolol (TENORMIN and generics) — are used to treat certain life-threatening heart-rhythm disorders, including ventricular tachycardia. In diabetic patients, these drugs can increase fasting blood glucose levels.[9]

There is evidence that certain beta blockers, such as atenolol, also contribute to new-onset diabetes and worsening hyperglycemia in obese individuals within nine weeks of therapy.

Certain antiretroviral drugs

Protease inhibitors, such as nelfinavir (VIRACEPT) and ritonavir (NORVIR and generics), are important therapies for the treatment of HIV infection.[10] These drugs are commonly associated with transient hyperglycemia.

There is evidence that protease inhibitors also can cause sustained elevation in blood glucose levels.

Glucocorticoids

All glucocorticoids are associated with hyperglycemia at doses greater than the equivalent of 7.5 milligrams per day of prednisolone (ORAPRED ODT, PEDIAPRED, PRELONE and generics).

Most hyperglycemia problems have been reported with oral glucocorticoids, such as dexamethasone (HEMADY and generics) and prednisone (generics only).

However, topical glucocorticoids also can induce severe hyperglycemia, particularly if applied at high dosage over large areas of damaged skin and under occlusive dressings.

Lipid-lowering drugs

Hyperglycemia and new-onset diabetes are well-recognized adverse effects of statins, including pravastatin (generics only) and rosuvastatin (CRESTOR and generics).[11] Notably, the hyperglycemia risk associated with these drugs seems to be slightly higher with intensive rather than moderate therapy.[12]

Likewise, worsening hyperglycemia and new-onset diabetes have been reported with the use of niacin (NIACOR and generics), which is indicated for reducing cholesterol levels and the risk of recurrent, nonfatal heart attacks in patients with a history of a previous heart attack and elevated cholesterol levels.[13]

Thiazide and thiazide-like diuretics

Thiazides (such as hydrochlorothiazide [INZIRQO, MICROZIDE and generics]) and thiazide-like drugs (such as metolazone [generics only]), which are often used to control high blood pressure, can cause hyperglycemia and, in some cases, contribute to the development of new-onset diabetes.[14] Such risks, however, may be lowered by the use of lower doses of these drugs and by correcting any drop in potassium blood levels (hypokalemia) associated with the use of these drugs.[15]

Other drugs

Hormonal birth control pills that contain estrogen or progestin tend to cause hyperglycemia, making it harder for diabetic patients to manage their blood glucose levels.[16] These drugs may cause weight gain, which also increases the risk of hyperglycemia because it causes insulin resistance.

Additionally, the risk of hyperglycemia is well established with the use of organ transplant immunosuppressants, such as cyclosporine (GENGRAF, NEORAL, SANDIMMUNE and generic), sirolimus (RAPAMUNE and generics) and tacrolimus (ASTAGRAF XL, ENVARSUS XR, PROGRAF and generics).[17]

Synthetic human growth hormone drugs, such as somatropin (ACCRETROPIN, GENOTROPIN, HUMATROPE, others and biosimilars), have also been linked to hyperglycemia. Likewise, somatostatin analogues (most of which are given by injection, mainly to treat acromegaly [a condition caused by abnormally high levels of growth hormone in adults]) also can cause hyperglycemia. Examples of these drugs include lanreotide (SOMATULINE DEPOT and generics) and octreotide (BYNFEZIA PEN, MYCAPSSA, SANDOSTATIN and generics).

What You Can Do

Always ask your clinician about potential adverse effects associated with your medications, and consider the possibility of drug-induced hyperglycemia if you suddenly have hyperglycemia or uncontrolled diabetes. If you believe one of your medications is contributing to your hyperglycemia, ask your clinician for an alternative medication. If no alternatives are available, it may be possible to reduce the risk of developing drug-induced hyperglycemia by taking the smallest effective dose of the implicated medication for the shortest time, as recommended by your clinician. Regular screening for diabetes is needed in such cases.

Inform your clinician promptly if you develop any of the symptoms associated with high blood sugar levels, including the following:

• feeling more tired than usual
• feeling thirsty
• frequent urination, especially at night
• unintended weight loss

Keep in mind that other drugs that are not discussed in this article also may trigger drug-induced hyperglycemia. Therefore, it is important to review all your medications regularly with your clinician to minimize this risk.

Exercise regularly and maintain a healthy, balanced diet to help in maintaining normal blood glucose levels.
 

References

[1] American Diabetes Associations. Blood glucose & A1C. Understanding diabetes diagnosis. https://diabetes.org/about-diabetes/diagnosis. Accessed April 9, 2025.

[2] Robertson RP, Udler MS. Pathogenesis of type 2 diabetes mellitus. UpToDate. March 18, 2024.

[3] Rehman A, Setter SM, Vue MH. Drug-induced glucose alterations part 2: Drug-induced hyperglycemia. Diabetes Spectr. 2011;24(4):234-238.

[4] Lamb T. Drug injury watch. FDA: Tequin was withdrawn from U.S. market "for reasons of safety or effectiveness. September 10, 2008. https://www.drug-injury.com/druginjurycom/2008/09/tequin-gatifloxacin-was-withdrawn-from-sale-for-reasons-of-safety-or-effectiveness--federal-register-september-9-2008-v.html. Accessed April 9, 2025.

[5] Gittoes NJL, Ayuk J, Ferner RE. Drug-induced diabetes. In: Holt RIG, Cockram CS, Flyvbjerg A, et al, eds. Textbook of Diabetes. Blackwell Publishing Ltd; 2010:265-278.

[6] Fathallah N, Slim R, Larif S, et al. Drug-induced hyperglycaemia and diabetes. Drug Saf. 2015;38(12):1153-1168.

[7] Verrotti A, Manco R, Agostinelli S, et al. The metabolic syndrome in overweight epileptic patients treated with valproic acid. Epilepsia. 2010;51(2):268-273.

[8] Gittoes NJL, Ayuk J, Ferner RE. Drug-induced diabetes. In: Holt RIG, Cockram CS, Flyvbjerg A, et al, eds. Textbook of Diabetes. Blackwell Publishing Ltd; 2010:265-278.

[9] Rehman A, Setter SM, Vue MH. Drug-induced glucose alterations part 2: Drug-induced hyperglycemia. Diabetes Spectr. 2011;24(4):234-238.

[10] Gittoes NJL, Ayuk J, Ferner RE. Drug-induced diabetes. In: Holt RIG, Cockram CS, Flyvbjerg A, et al, eds. Textbook of Diabetes. Blackwell Publishing Ltd; 2010:265-278.

[11] Fathallah N, Slim R, Larif S, et al. Drug-induced hyperglycaemia and diabetes. Drug Saf. 2015;38(12):1153-1168.

[12] Rosenson RS. Statins: Actions, side effects, and administration. UpToDate. April 23, 2024.

[13] Drug profile: Niacin (NIASPAN). October 31, 2024. https://www.worstpills.org/monographs/view/194. Accessed April 9, 2025.

[14] Rehman A, Setter SM, Vue MH. Drug-induced glucose alterations part 2: Drug-induced hyperglycemia. Diabetes Spectr. 2011;24(4):234-238.

[15] Gittoes NJL, Ayuk J, Ferner RE. Drug-induced diabetes. In: Holt RIG, Cockram CS, Flyvbjerg A, et al, eds. Textbook of Diabetes. Blackwell Publishing Ltd; 2010:265-278.

[16] Centers for Disease Control and Prevention. Diabetes and hormonal birth control. August 8, 2024. https://www.cdc.gov/diabetes/articles/diabetes-and-hormonal-birth-control.html. Accessed April 9, 2025.

[17] Fathallah N, Slim R, Larif S, et al. Drug-induced hyperglycaemia and diabetes. Drug Saf. 2015;38(12):1153-1168.