What is the equivalent dose of prednisolone for a patient requiring 100 mg of hydrocortisone?

Hydrocortisone to Prednisolone Dose Equivalency

100 mg of hydrocortisone is equivalent to 25 mg of prednisolone, based on the established 4:1 conversion ratio. 1, 2, 3

Standard Conversion Ratio

• The fundamental conversion is 20 mg hydrocortisone = 5 mg prednisolone, which establishes a 4:1 ratio consistently cited across multiple authoritative guidelines 1, 2, 3
• Using this ratio: 100 mg hydrocortisone ÷ 4 = 25 mg prednisolone 2
• The FDA drug label for hydrocortisone explicitly states that "20 mg of hydrocortisone is equivalent to 5 mg of prednisolone" 3

Clinical Validation

• This conversion ratio is validated across multiple clinical contexts including perioperative steroid management, where guidelines consistently reference the 4:1 hydrocortisone-to-prednisolone equivalency 1, 4, 2
• The Association of Anaesthetists guidelines confirm that 10 mg hydrocortisone is roughly equivalent to 2.0 mg prednisolone, which maintains the same 5:1 ratio (or 4:1 when comparing 20 mg to 5 mg) 1
• Multiple perioperative management protocols use this conversion when transitioning patients between IV hydrocortisone and oral prednisolone 4, 2

Important Clinical Caveats

• This conversion reflects anti-inflammatory potency only—prednisolone has approximately 25 times less mineralocorticoid activity than hydrocortisone, which becomes clinically relevant in primary adrenal insufficiency 2
• For patients with primary adrenal insufficiency requiring mineralocorticoid replacement, prednisolone alone is inadequate and fludrocortisone supplementation is necessary 5
• The conversion assumes equivalent bioavailability; both agents have excellent oral absorption, though individual patient factors (hepatic enzyme inducers, critical illness) may alter pharmacokinetics 1