Steroid Dose Equivalence
The standard dose equivalence for commonly used corticosteroids is: 5 mg prednisone = 20 mg hydrocortisone = 0.75 mg dexamethasone. 1, 2
Detailed Corticosteroid Equivalence Table
| Corticosteroid | Equivalent Dose (mg) | Relative Potency | Duration of Action |
|---|---|---|---|
| Hydrocortisone | 20 | 1 | Short (8-12h) |
| Prednisone | 5 | 4 | Intermediate (12-36h) |
| Methylprednisolone | 4 | 5 | Intermediate (12-36h) |
| Dexamethasone | 0.75 | 25-30 | Long (36-72h) |
| Betamethasone | 0.6 | 30 | Long (36-72h) |
Clinical Applications of Steroid Equivalence
Perioperative Management
- For patients on chronic steroids (≥5 mg prednisone equivalent for ≥4 weeks):
Switching Between Steroids
When transitioning between different corticosteroids:
- Calculate the total daily dose equivalent
- Consider the duration of action when determining dosing frequency
- Example: Converting from prednisone 20 mg daily to hydrocortisone would require 80 mg hydrocortisone, typically divided as 2/3 in morning, 1/3 in afternoon 1
Special Considerations
Mineralocorticoid Activity
- Hydrocortisone has significant mineralocorticoid activity
- Prednisone has moderate mineralocorticoid activity
- Dexamethasone has minimal mineralocorticoid activity 1, 2
- Important: Dexamethasone is inadequate as sole glucocorticoid coverage in primary adrenal insufficiency due to lack of mineralocorticoid activity 1, 2
Dosing Frequency
- Hydrocortisone: Typically divided (2/3 morning, 1/3 afternoon) to mimic diurnal rhythm 1
- Prednisone: Once or twice daily dosing
- Dexamethasone: Once daily dosing due to long half-life 2
Clinical Pearls
- For IBD patients requiring surgery: Prednisolone 5 mg is equivalent to hydrocortisone 20 mg 1
- For adrenal insufficiency: Hydrocortisone 15-20 mg daily in divided doses is standard replacement 1
- For COVID-19 ARDS: Dexamethasone 6 mg daily = methylprednisolone 32 mg daily = hydrocortisone 150 mg daily 3
Common Pitfalls to Avoid
- Underdosing in stress situations: Patients on chronic steroids require stress-dose steroids during surgery or acute illness
- Abrupt discontinuation: Taper steroids gradually after prolonged use (>3 weeks) to prevent adrenal insufficiency 2
- Overlooking mineralocorticoid needs: Patients with primary adrenal insufficiency require mineralocorticoid replacement in addition to glucocorticoids 1
- Incorrect conversion: Using inaccurate conversion factors can lead to under or over-replacement
By understanding these equivalences and considerations, clinicians can appropriately dose corticosteroids across different clinical scenarios, ensuring optimal outcomes while minimizing adverse effects.