How do I convert prednisone (corticosteroid) 10mg orally once daily to an intravenous (IV) regimen?

Converting Oral Prednisone 10mg Daily to IV Equivalent

The equivalent intravenous (IV) dose for oral prednisone 10mg once daily is 8mg of IV methylprednisolone once daily.

Corticosteroid Conversion Principles

When converting from oral prednisone to IV methylprednisolone, several key factors must be considered:

1. Relative Potency: Methylprednisolone is approximately 1.25 times more potent than prednisone 1
2. Bioavailability: Oral prednisone has approximately 80% bioavailability compared to IV administration
3. Conversion Factor: The standard conversion ratio is 4:5 (IV methylprednisolone:oral prednisone)

Conversion Calculation

The conversion can be calculated as follows:

• Oral prednisone 10mg daily
• Conversion factor: 10mg oral prednisone × 0.8 = 8mg IV methylprednisolone

Administration Guidelines

IV Methylprednisolone Administration

• Administer 8mg IV methylprednisolone once daily
• May be given as a slow IV push over several minutes 1
• Can be diluted in appropriate solutions (5% dextrose in water, isotonic saline) for infusion if needed

Important Considerations

• Monitoring: Monitor for potential adverse effects including:

  • Hyperglycemia
  • Hypertension
  • Electrolyte abnormalities
  • Mood disturbances

• Duration: If transitioning from oral to IV temporarily, maintain the same dosing schedule (once daily) unless clinically indicated otherwise

• Return to Oral: When converting back to oral prednisone, use the same conversion factor in reverse (8mg IV methylprednisolone = 10mg oral prednisone)

Special Situations

• High-Dose Pulse Therapy: For acute exacerbations of certain conditions, higher doses (250-1000mg) may be used 1, but this is not equivalent to the maintenance dose of 10mg oral prednisone

• Pediatric Patients: In children, dosing should be based on weight (0.5-1.6 mg/kg/day) rather than using adult equivalents 1

Cautions

• Rapid IV administration of large doses (>500mg) over less than 10 minutes has been associated with cardiac arrhythmias 1
• IV corticosteroids should be used with caution in patients with heart failure, hypertension, or electrolyte abnormalities

Remember that this conversion is based on standard pharmacological principles, but individual patient factors may necessitate dose adjustments based on clinical response and tolerability.