What is the equivalent dose of methyleprednisolone (methylprednisolone) to hydrocortisone 100 mg intramuscularly (IM)?

From the Guidelines

The equivalent dose of methylprednisolone to hydrocortisone 100 mg IM is approximately 20 mg IM, considering the relative potencies of these corticosteroids. When converting between corticosteroids, it's crucial to account for their relative potencies. Methylprednisolone has approximately 5 times the anti-inflammatory potency of hydrocortisone, which means you need only one-fifth of the hydrocortisone dose to achieve equivalent effects. According to the British Society of Gastroenterology consensus guidelines on the management of inflammatory bowel disease in adults 1, methylprednisolone has less mineralocorticoid effect than hydrocortisone at these doses and so causes significantly less hypokalaemia.

Key points to consider when administering methylprednisolone IM include:

• The onset of action is relatively rapid, with effects typically beginning within hours
• The medication should be injected deep into the gluteal muscle to ensure proper absorption and minimize local tissue reactions
• Be mindful of potential side effects including hyperglycemia, fluid retention, and immunosuppression, particularly with repeated dosing
• The guidelines suggest that a dose of 60 mg methylprednisolone is equivalent to 400 mg hydrocortisone, which further supports the potency ratio used for the conversion 1.

Given the information provided and the need to prioritize morbidity, mortality, and quality of life, the recommended equivalent dose of methylprednisolone for hydrocortisone 100 mg IM remains approximately 20 mg IM, taking into account the established relative potency ratios and clinical guidelines 1.

From the FDA Drug Label

For the purpose of comparison, the following is the equivalent milligram dose of the various glucocorticoids: Cortisone, 25 Triamcinolone, 4 Hydrocortisone, 20 Paramethasone, 2 Prednisolone, 5 Betamethasone, 0.75 Prednisone, 5 Dexamethasone, 0. 75 Methylprednisolone, 4 These dose relationships apply only to oral or intravenous administration of these compounds.

The equivalent dose of methylprednisolone to hydrocortisone 100 mg can be calculated using the given conversion factor:

• Hydrocortisone is equivalent to 20 mg of methylprednisolone per 20 mg of hydrocortisone
• So, 100 mg of hydrocortisone is equivalent to (100 mg * 4 mg / 20 mg) = 20 mg of methylprednisolone However, the conversion factor provided is for oral or intravenous administration. Since the question is about intramuscular (IM) administration, and the label states that relative properties may be greatly altered when injected intramuscularly, we cannot accurately determine the equivalent dose of methylprednisolone for hydrocortisone 100 mg IM based on the provided information 2.

From the Research

Equivalent Dose of Methyleprednisolone to Hydrocortisone

To determine the equivalent dose of methyleprednisolone to hydrocortisone 100 mg intramuscularly (IM), we need to consider the potency and dosage of each steroid.

• The study 3 defines three broad categories of corticosteroid dose (equivalent dose of methylprednisolone in 24 hours) as low dose (< or = 80 mg), medium dose (> 80 mg and < or = 360 mg) and high dose (> 360 mg), and also mentions that low dose corticosteroids (< or = 80 mg/day of methylprednisolone or < or = 400 mg/day of hydrocortisone) appear to be adequate in the initial management of adult patients with acute severe asthma.
• Another study 4 compares the antirheumatic potencies of several compounds, including 16a-methylprednisolone (approximately one-third greater than prednisolone) and 16a-methylhydrocortisone (about 70 per cent that of prednisolone).
• However, the most relevant information for determining the equivalent dose comes from the study 5, which compares the efficacy of hydrocortisone and methylprednisolone in acute severe asthma. This study uses intravenous hydrocortisone 200 mg 4-hourly and intravenous methylprednisolone 125 mg 12-hourly, suggesting that the equivalent dose of methylprednisolone to hydrocortisone 100 mg may be around 62.5 mg (assuming a 12-hourly dose of methylprednisolone is equivalent to a 4-hourly dose of hydrocortisone).
• It's also worth noting that the study 6 examines the short-term airway response of subjects with severe asthma to equivalent low doses of intravenous hydrocortisone, methylprednisolone, and dexamethasone, but does not provide a clear equivalent dose for hydrocortisone 100 mg IM.

Key Points

• The equivalent dose of methyleprednisolone to hydrocortisone 100 mg IM is not explicitly stated in the provided studies.
• However, based on the study 5, the equivalent dose of methylprednisolone may be around 62.5 mg.
• The study 3 suggests that low dose corticosteroids (< or = 80 mg/day of methylprednisolone or < or = 400 mg/day of hydrocortisone) appear to be adequate in the initial management of adult patients with acute severe asthma.
• Further studies, such as 7, do not provide a clear equivalent dose for hydrocortisone 100 mg IM, but rather compare the effects of methylprednisolone and hydrocortisone in different contexts.