What is the difference between prednisone and prednisolone?

Difference Between Prednisone and Prednisolone

Prednisolone is the active form of prednisone and is preferred in patients with liver disease, as prednisone requires hepatic conversion to become active. 1

Pharmacological Differences

Chemical Structure and Activation

• Prednisone: A synthetic corticosteroid that is a prodrug

  • Must be converted to prednisolone in the liver through first-pass metabolism to become active
  • Requires adequate liver function for proper activation 1

• Prednisolone: The active metabolite of prednisone

  • Directly active without requiring hepatic conversion
  • More predictable plasma levels in patients with normal liver function 1

Bioavailability

• In patients with normal liver function:

  • Both medications have similar overall bioavailability
  • Prednisolone produces approximately 14% higher peak plasma levels
  • Prednisolone reaches peak concentration about 20% faster than prednisone tablets 2

• In patients with liver disease:

  • Prednisone shows impaired activation to prednisolone
  • Plasma prednisolone levels are more predictable when prednisolone is administered directly 1

Clinical Implications

Patient Selection

Prednisolone is preferred over prednisone in:

• Patients with liver disease or hepatic dysfunction
• Situations where more predictable plasma levels are needed
• Cases where rapid onset of action is desired

Dosing Equivalence

• Prednisone and prednisolone are used in equivalent doses
• Both are typically administered at:
  • 1 mg/kg/day (maximum 80 mg) as a single daily dose, or
  • 2 mg/kg/day (maximum 120 mg) as an alternate-day dose 3

Therapeutic Applications

Both medications are used similarly in various conditions:

• Inflammatory bowel disease: Initial dose of 40-60 mg daily with tapering 3
• Autoimmune hepatitis: Starting at 60 mg/day or 30 mg/day with azathioprine 3
• Glomerulonephritis: 1 mg/kg/day (maximum 80 mg) or alternate-day dosing 3
• Atopic dermatitis: 0.5-1.0 mg/kg when systemic therapy is needed 3

Common Pitfalls and Considerations

Liver Disease

• Critical consideration: In patients with significant liver disease, prednisolone is strongly preferred as prednisone conversion may be impaired 1
• Research shows that patients with active hepatocellular necrosis have impaired activation of prednisone to prednisolone 1

Side Effect Profile

• Both medications have identical side effect profiles when equivalent doses are used
• Common side effects include:
  • Hypertension
  • Glucose intolerance
  • Weight gain
  • Decreased bone density
  • Adrenal suppression
  • Emotional lability 3

Tapering Recommendations

• For both medications, slow tapering is essential to avoid adrenal insufficiency
• Typical tapering schedule:
  • Reduce by 5 mg weekly until reaching 10 mg/day
  • Then reduce by 2.5 mg weekly until reaching 5 mg/day 3
  • Total tapering period of 6 months after achieving remission in many conditions 3

Practical Considerations

Cost and Availability

• Both medications are widely available in oral formulations
• Prednisolone is available as an oral solution which may be preferred for patients who have difficulty swallowing tablets

Monitoring

• Both medications require the same monitoring:
  • Blood pressure
  • Blood glucose
  • Bone mineral density (baseline and annual)
  • Signs of adrenal insufficiency during tapering

In summary, while prednisone and prednisolone are pharmacologically similar and used interchangeably in most patients with normal liver function, prednisolone is the preferred option in patients with liver disease or when more predictable plasma levels are required.