Glucocorticoid Equivalent Doses
The standard conversion ratios for glucocorticoids relative to prednisone are: methylprednisolone 1.25× (4mg methylprednisolone = 5mg prednisone), dexamethasone 6.67× (0.75mg dexamethasone = 5mg prednisone), and hydrocortisone 0.25× (20mg hydrocortisone = 5mg prednisone). 1
Detailed Conversion Table
| Glucocorticoid | Equivalent Dose (mg) | Potency Ratio Relative to Prednisone |
|---|---|---|
| Prednisone | 5 | 1× |
| Prednisolone | 5 | 1× |
| Methylprednisolone | 4 | 1.25× |
| Dexamethasone | 0.75 | 6.67× |
| Hydrocortisone | 20 | 0.25× |
Clinical Applications and Dosing
Conversion Principles
- Methylprednisolone has 1.25 times the potency of prednisone, meaning that 4mg methylprednisolone equals 5mg prednisone 1
- Hydrocortisone is the least potent, with 20mg hydrocortisone equivalent to 5mg prednisone 2
- Dexamethasone is the most potent systemic corticosteroid commonly used, with approximately 25 times greater potency than short-acting products like hydrocortisone 3
Medium to High-Dose Therapy
- Medium to high-dose glucocorticoid therapy is defined as >7.5 mg but ≤100 mg prednisone equivalent daily 4
- For polymyalgia rheumatica, oral prednisone 12.5-25 mg/day can be converted to equivalent doses of intramuscular methylprednisolone 1
- For multiple sclerosis acute exacerbations, 200mg prednisolone daily (equivalent to 160mg methylprednisolone) followed by 80mg every other day is recommended 5, 2
Specific Disease Recommendations
- For idiopathic focal segmental glomerulosclerosis (FSGS) with nephrotic syndrome, prednisone is recommended at a daily single dose of 1 mg/kg (maximum 80 mg) or alternate-day dose of 2 mg/kg (maximum 120 mg) 4
- For immune-related adverse events, prednisone 0.5-1 mg/kg/day or equivalent methylprednisolone dose is recommended 1
Pharmacological Considerations
Administration Timing
- Modified-release prednisone or prednisolone taken at bedtime may lead to lower morning stiffness and IL-6 levels compared to usual morning administration 6
- For rheumatoid arthritis, some evidence suggests that 5mg prednisolone at night may be preferred to 5mg prednisone in the morning 6
Duration of Action
- Short-acting: Hydrocortisone
- Intermediate-acting: Prednisone, Prednisolone, Methylprednisolone
- Long-acting: Dexamethasone 3
Special Considerations
- Methylprednisolone has less mineralocorticoid effect at equivalent doses than prednisone, causing less hypokalemia 1
- Patients with liver disease may have impaired conversion of prednisone (an 11-keto compound) to prednisolone (the active 11-beta-hydroxyl compound) 7
- Dexamethasone has minimal mineralocorticoid activity and is inadequate as glucocorticoid stress cover in patients with primary adrenal insufficiency 4
Monitoring Recommendations
For patients on low-dose glucocorticoid therapy (≤7.5 mg prednisone equivalent daily), standard care monitoring does not need to be extended except for:
- Osteoporosis (follow national guidelines)
- Baseline assessments of ankle edema
- Fasting blood glucose
- Risk factors for glaucoma 4
For medium to high-dose therapy, more extensive monitoring is required to assess potential adverse effects on bone health, cardiovascular system, and metabolic parameters 4.
Remember that dosage requirements are variable and must be individualized based on the disease being treated and the patient's response 5, 2.