Are Prednisone and Prednisolone the Same Thing?
Yes, prednisone and prednisolone are clinically equivalent medications that can be used interchangeably at the same dosage. 1, 2
Pharmacological Equivalence
The KDIGO (Kidney Disease: Improving Global Outcomes) guidelines explicitly state that prednisone and prednisolone are equivalent, used in the same dosage, and have both been used interchangeably in randomized controlled trials depending on the country of origin. 1
The American College of Nephrology confirms that all references to prednisone in major nephrology guidelines apply equally to prednisolone. 2
The FDA drug labels confirm that both medications are glucocorticoids with predominantly glucocorticoid properties and similar mechanisms of action. 3, 4
Key Biochemical Relationship
Prednisone is a prodrug that must be converted to prednisolone in the liver to become active. 3, 5
This conversion happens rapidly and efficiently in nearly all patients, even those with severe liver disease. 5, 6, 7
The FDA label for prednisolone notes that "the systemic availability, metabolism and elimination of prednisolone after administration of single weight-based doses of intravenous prednisolone and oral prednisone were independent of age." 3
Clinical Implications for Prescribing
Geographic prescribing patterns:
- Prednisone is more commonly prescribed in the United States. 2
- Prednisolone is more commonly prescribed in Europe and other regions. 2
- The choice between the two typically depends on local availability rather than clinical superiority. 2
Dosing equivalence:
- 5 mg prednisone = 5 mg prednisolone 8
- Both medications use identical dosing regimens (e.g., 1 mg/kg daily for nephrotic syndrome). 2
Important Caveats
When prednisolone may be preferred:
- In the rare patient with severely impaired hepatic conversion of prednisone to prednisolone (approximately 2 out of 10 patients in one study showed markedly inefficient conversion). 5
- Prednisolone provides more predictable plasma levels in patients without hepatic dysfunction. 5
- However, even in patients with active hepatocellular necrosis, impaired activation of prednisone is compensated for by decreased elimination of prednisolone, resulting in similar clinical effects. 5, 7
Practical consideration:
- Studies demonstrate that prednisone and prednisolone reach rapid interconversion equilibrium in the body, with peak serum prednisolone concentrations being 4-5 times those of prednisone after administration of either drug. 7
- Clinical trials have used both medications successfully with no difference in outcomes. 1