From the Guidelines
To convert Solumedrol (methylprednisolone) to prednisone, use a 1:1.25 ratio, meaning 4 mg of methylprednisolone is equivalent to 5 mg of prednisone, as supported by the most recent guidelines 1. When transitioning between these medications, it's crucial to maintain equivalent anti-inflammatory and immunosuppressive effects to prevent disease flare or withdrawal symptoms. The conversion is necessary because methylprednisolone has approximately 20% greater glucocorticoid activity than prednisone, making it more potent on a milligram-per-milligram basis. Some key points to consider when converting between these steroids include:
- The potency difference between methylprednisolone and prednisone
- The bioavailability of oral prednisone, which is about 80%, and how this may affect dosing when switching from IV Solumedrol
- The importance of gradual tapering for patients on high-dose or prolonged steroid therapy to prevent adrenal insufficiency, as recommended in the management of systemic lupus erythematosus 1
- Common scenarios where conversion is necessary, such as transitioning from IV steroids during hospitalization to oral steroids for outpatient management of conditions like asthma exacerbations, autoimmune disorders, or inflammatory conditions. For example, if a patient is receiving 40 mg of Solumedrol, the equivalent prednisone dose would be 50 mg, based on the 1:1.25 conversion ratio. It's also important to note that the management of conditions such as systemic lupus erythematosus involves minimizing glucocorticoid doses to less than 7.5 mg/day (prednisone equivalent) for chronic maintenance treatment, as outlined in the 2019 update of the EULAR recommendations 1.
From the FDA Drug Label
4 mg of methylprednisolone is equivalent to 5 mg of prednisolone The conversion from Methylprednisolone (Solumedrol) to Prednisone is based on the equivalence to prednisolone, which is 0.8 mg of prednisone is equivalent to 1 mg of prednisolone (not directly stated in the label, but a general conversion factor). Using the information from the label, 4 mg of methylprednisolone is equivalent to 5 mg of prednisolone, and then converting prednisolone to prednisone: 5 mg of prednisolone is equivalent to 4 mg of prednisone. Therefore, the conversion is approximately 1 mg of methylprednisolone is equivalent to 1 mg of prednisone (using the conversion factor of 0.8 mg of prednisone per 1 mg of prednisolone) 2.
From the Research
Conversion from Methylprednisolone to Prednisone
- The conversion from Methylprednisolone (Solumedrol) to Prednisone is not directly stated in the provided studies, but we can infer the equivalent doses from the study 3.
- In the study 3, patients received either 1,000 mg of intravenous Solu-Medrol (methylprednisolone) or a bolus dose of 100 mg of oral prednisone for 3 days.
- Another study 4 mentions that pulse steroid treatment with 0.25- to 1.0-g pulses of methylprednisolone is the usual first-line therapy, and orally administered prednisone (0.25 g) may be just as efficacious.
- However, the exact conversion ratio between methylprednisolone and prednisone is not explicitly stated in these studies.
Equivalent Doses
- Based on the study 5, patients received pulses of 125mg of methylprednisolone with each fortnightly pulse of cyclophosphamide and prednisone ≤30mg/day.
- This suggests that the dose of methylprednisolone is approximately 4-5 times higher than the dose of prednisone, but this is not a direct conversion ratio.
- More research is needed to determine the exact conversion ratio between methylprednisolone and prednisone, as the provided studies do not offer a clear answer 3, 5, 4.