Is Solucortef (hydrocortisone) 100 mg intramuscularly (IM) and hydrocortisone 20 mg orally (PO) 4 times a day equivalent to methylprednisolone 100 mg intravenously (IV)?

Corticosteroid Dose Equivalency Assessment

Direct Answer

No, Solu-Cortef (hydrocortisone) 100 mg IM plus hydrocortisone 20 mg PO four times daily (total 180 mg hydrocortisone/day) is NOT equivalent to methylprednisolone 100 mg IV—it provides approximately 3.6 times MORE corticosteroid effect than methylprednisolone 100 mg. 1

Dose Equivalency Calculations

Standard Conversion Ratios

The FDA-approved equivalency table establishes that:

• Hydrocortisone 20 mg = Methylprednisolone 4 mg 1
• This means methylprednisolone is 5 times more potent than hydrocortisone 1, 2

Your Regimen Breakdown

Total daily hydrocortisone dose:

• 100 mg IM (once) = 100 mg
• 20 mg PO × 4 times = 80 mg
• Total = 180 mg hydrocortisone per day 3

Methylprednisolone equivalent:

• 180 mg hydrocortisone ÷ 5 = 36 mg methylprednisolone equivalent
• You are comparing this to 100 mg methylprednisolone IV
• The methylprednisolone dose is 2.8 times higher than what your hydrocortisone regimen provides 1

Clinical Context from Guidelines

Acute Severe Conditions

For acute severe ulcerative colitis, guidelines recommend either:

• Methylprednisolone 60 mg IV per 24 hours (given as 30 mg every 12 hours), OR 4
• Hydrocortisone 400 mg IV per 24 hours (given as 100 mg every 6 hours) 4

This 400 mg hydrocortisone = 60 mg methylprednisolone equivalency confirms the 5:1 potency ratio in clinical practice 4

Septic Shock Dosing

For septic shock, the recommended regimen is:

• Hydrocortisone 200 mg per day (50 mg every 6 hours), which equals approximately 40 mg methylprednisolone per day 4, 5, 6, 7

Route of Administration Considerations

Bioavailability Differences

• Oral hydrocortisone has approximately 96% bioavailability, so the 80 mg PO portion contributes nearly its full dose 3
• IM hydrocortisone is completely absorbed but may have delayed peak levels compared to IV 3
• The combination of IM + PO routes does not significantly alter total systemic exposure over 24 hours 3

Correct Equivalent Regimens

If Target is Methylprednisolone 100 mg IV:

To match 100 mg methylprednisolone, you would need:

• Hydrocortisone 500 mg per day (e.g., 125 mg IV every 6 hours) 1

If Using Your Hydrocortisone Regimen (180 mg/day):

Your current regimen of 180 mg hydrocortisone per day is equivalent to:

• Methylprednisolone 36 mg per day 1

Important Clinical Caveats

Mineralocorticoid Activity

• Hydrocortisone has significant mineralocorticoid activity while methylprednisolone has minimal 2
• This affects fluid retention, electrolyte balance, and blood pressure support 2
• In septic shock, hydrocortisone's mineralocorticoid effect may provide additional hemodynamic benefit 4, 5

Duration and Timing

• Hydrocortisone has a shorter half-life (8-12 hours) requiring multiple daily doses 2
• Methylprednisolone has intermediate duration (12-36 hours) allowing less frequent dosing 2
• Your regimen with IM morning dose plus QID oral dosing provides more sustained coverage than a single methylprednisolone dose 3

Clinical Outcomes Data

Recent comparative studies show:

• No significant difference in 30-day mortality between hydrocortisone and methylprednisolone in septic shock when dosed appropriately 6, 7
• Time to shock reversal is similar between equivalent doses 5, 7
• Mechanistic studies confirm dose equivalency tables are valid across multiple biomarkers including lymphocyte trafficking and adrenal suppression 8

Practical Recommendation

If you need to match methylprednisolone 100 mg IV effect, increase your hydrocortisone regimen to approximately 500 mg total daily dose (e.g., hydrocortisone 125 mg IV/IM every 6 hours), or reduce the methylprednisolone comparison dose to 36 mg to match your current 180 mg hydrocortisone regimen. 1, 3