What is the equivalent dose of methylprednisolone (corticosteroid) to hydrocortisone (corticosteroid) for an adult patient with suspected leprosy?

Methylprednisolone to Hydrocortisone Dose Equivalence

Methylprednisolone 60 mg daily is equivalent to hydrocortisone 300-400 mg daily, based on a 5:1 potency ratio (methylprednisolone is 5 times more potent than hydrocortisone). 1

Standard Conversion Ratios

The established potency relationships between these corticosteroids are:

• Methylprednisolone is 5 times more potent than hydrocortisone 1
• Therefore, 1 mg methylprednisolone = 5 mg hydrocortisone
• Conversely, 20 mg hydrocortisone = 4 mg methylprednisolone 2

Practical Conversion Examples

Common Clinical Scenarios

For septic shock management:

• Hydrocortisone <400 mg/day (typically 100 mg every 6 hours = 400 mg/day) is the recommended dose 3
• This equates to methylprednisolone 60-80 mg daily 3
• The British Society of Gastroenterology specifically states that methylprednisolone 60 mg daily equals hydrocortisone 100 mg every 6 hours (400 mg/day total) 3

For acute severe conditions:

• Hydrocortisone 300 mg/day = methylprednisolone 60 mg/day 3
• Prednisolone 75 mg/day = hydrocortisone 300 mg/day 3

FDA-Approved Equivalence Table

According to the FDA prednisolone label, the following conversions apply 4:

• Hydrocortisone 60 mg = Methylprednisolone 12 mg = Prednisolone 15 mg
• This confirms the 5:1 ratio (60÷12 = 5)

Important Clinical Considerations

Mineralocorticoid effects differ significantly:

• Methylprednisolone has minimal mineralocorticoid activity at therapeutic doses 3
• Hydrocortisone has substantial mineralocorticoid effects, causing more hypokalaemia and sodium retention 3
• When converting from hydrocortisone to methylprednisolone, monitor potassium levels as supplementation needs may decrease 3

Route of administration matters:

• These conversion ratios apply to oral and intravenous routes 4
• When injected intramuscularly or into joint spaces, relative potencies may be altered 4

Duration and dosing strategy:

• For septic shock, use hydrocortisone <400 mg/day for ≥3 days at full dose rather than high-dose short courses 3
• Methylprednisolone 60 mg daily can be given as a single daily dose, while hydrocortisone is typically divided (e.g., 100 mg every 6 hours) 3

Context-Specific Guidance for Leprosy

While the question mentions leprosy, the conversion ratios remain the same regardless of indication. For leprosy type 1 reactions:

• Standard treatment uses oral prednisolone starting at 40 mg/day, tapered over 16 weeks 5
• High-dose intravenous methylprednisolone (1 gram daily for 3 days) has been studied but showed limited additional benefit over oral prednisolone alone 6
• The same 5:1 conversion ratio applies when switching between methylprednisolone and hydrocortisone in this population 1