Prednisolone 30mg Converts to Hydrocortisone 120mg
For a patient taking prednisolone 30mg daily, the equivalent hydrocortisone dose is 120mg daily. This conversion is based on the standard glucocorticoid equivalency ratio where prednisolone is approximately 4 times more potent than hydrocortisone 1, 2.
Conversion Calculation
The FDA drug labels provide the definitive conversion ratio:
- 20mg hydrocortisone = 5mg prednisolone 1
- This establishes a 4:1 ratio (hydrocortisone:prednisolone)
- Therefore: 30mg prednisolone × 4 = 120mg hydrocortisone
Dosing Schedule Considerations
When converting to hydrocortisone, the total daily dose should be divided appropriately:
Standard hydrocortisone dosing pattern 3, 4:
- Split into 2-3 divided doses per day
- Highest dose in the morning upon awakening
- For 120mg total daily: Consider 60mg morning, 40mg midday, 20mg afternoon
- Alternatively: 60mg morning, 60mg early afternoon (two-dose regimen)
Key difference from prednisolone:
- Prednisolone 30mg can be given once daily due to longer half-life 4
- Hydrocortisone requires multiple daily doses to mimic physiologic cortisol patterns
Clinical Context Matters
Important caveats:
This is a supraphysiologic dose: Normal physiologic replacement is only 15-25mg hydrocortisone daily 4. A dose of 120mg hydrocortisone (equivalent to prednisolone 30mg) represents treatment for active inflammatory disease, not adrenal replacement.
For stress dosing: If converting for stress coverage in someone with adrenal insufficiency, the 2024 ESE/Endocrine Society guidelines recommend hydrocortisone 40mg daily (split dosing) as the standard stress dose 3, which would be roughly equivalent to prednisolone 10mg.
Bone and metabolic effects: Higher doses like 120mg hydrocortisone daily carry significant risks for bone loss and metabolic complications. Recent evidence suggests prednisolone may actually have slower bone turnover than equivalent hydrocortisone doses 5, though this was studied at replacement doses, not supraphysiologic doses.
Practical Application
If converting for therapeutic purposes (inflammatory disease):
- Use the 4:1 ratio: 30mg prednisolone = 120mg hydrocortisone daily
- Divide hydrocortisone into 2-3 doses
- Monitor for glucocorticoid excess clinically (weight gain, hyperglycemia, hypertension) 4
If converting for adrenal insufficiency replacement:
- Question whether 30mg prednisolone is appropriate—this far exceeds physiologic needs
- Standard replacement is 3-5mg prednisolone daily or 15-25mg hydrocortisone daily 4
The 4:1 conversion ratio is well-established and validated across multiple sources 1, 2, 6, making 120mg hydrocortisone the mathematically correct equivalent to 30mg prednisolone.