From the Guidelines
Dexamethasone significantly increases blood glucose levels in both diabetic and non-diabetic patients, requiring careful monitoring and potential insulin dose adjustments to prevent hyperglycemia-related morbidity and mortality. The effect of dexamethasone on glucose levels is dose-dependent, with higher doses causing more pronounced elevations than lower doses 1. This occurs because dexamethasone promotes gluconeogenesis in the liver, increases insulin resistance in peripheral tissues, and reduces glucose uptake by cells.
Key Considerations
- For diabetic patients, glucose levels may rise by 20-40% or more, often requiring temporary insulin dose adjustments of 20-30% when on dexamethasone 1.
- Non-diabetic patients may experience blood glucose readings of 140-200 mg/dL or higher.
- The hyperglycemic effect typically resolves within 1-2 days after discontinuing the medication, though this varies based on treatment duration and individual factors.
- Patients taking dexamethasone should monitor blood glucose levels regularly, especially those with diabetes or prediabetes.
Management Strategies
- For long-acting glucocorticoids such as dexamethasone, long-acting basal insulin may be required to manage fasting blood glucose levels 1.
- For higher doses of glucocorticoids, increasing doses of prandial and correctional insulin, sometimes as much as 40-60% or more, are often needed in addition to basal insulin 1.
- Administering intermediate-acting (NPH) insulin is a standard approach for subjects on once- or twice-daily steroids, and it is recommended to administer it concomitantly with intermediate-acting steroids 1.
Monitoring and Adjustments
- Regular monitoring of blood glucose levels is crucial, especially in patients with diabetes or prediabetes.
- Adjustments to insulin doses should be based on anticipated changes in glucocorticoid dosing and point-of-care glucose test results 1.
From the FDA Drug Label
Glucocorticoids cause profound and varied metabolic effects The effect of dexamethasone on glucose levels is that it can cause hyperglycemia due to its metabolic effects as a glucocorticoid.
- Key points:
- Glucocorticoids have profound metabolic effects
- Dexamethasone is a synthetic glucocorticoid
- It can be expected to increase glucose levels 2
From the Research
Effect of Dexamethasone on Glucose Levels
- Dexamethasone has been shown to increase blood glucose levels in various studies 3, 4, 5, 6, 7.
- A study published in 2013 found that dexamethasone therapy resulted in an average blood glucose level of 301 ± 57 mg/dL in the sliding scale regular insulin group and 219 ± 51 mg/dL in the basal bolus insulin group 3.
- Another study published in 2021 used continuous glucose monitoring to describe the glycemic profile following a single dose of intravenous dexamethasone in a patient with diabetes, revealing a triphasic glycemic pattern 4.
- A systematic review published in 2022 found that diabetic patients who receive dexamethasone perioperatively are more likely to develop postoperative hyperglycemia, with a maximum blood glucose increase of 30 to 45 mg/dL in the first 24 hours following a single dose 5.
- A study published in 2024 found no significant difference in the impact of oral and intravenous dexamethasone on blood glucose levels in adult inpatients 6.
- A study published in 2010 found that a single oral dose of 8-mg dexamethasone increases blood glucose, insulin, and C-peptide levels maximally at 24 hours, 1 hour following a 75-g oral glucose tolerance test 7.
Key Findings
- Dexamethasone can cause hyperglycemia in patients with diabetes 3, 4, 5.
- The effect of dexamethasone on glucose levels can be managed with basal bolus insulin regimens 3, 4.
- The route of administration (oral or intravenous) does not significantly impact the effect of dexamethasone on blood glucose levels 6.
- A single dose of dexamethasone can increase blood glucose levels for up to 48 hours 7.