Methylprednisolone is a synthetic glucocorticoid, an agonist of glucocorticoid and mineralocorticoid receptors, and an active metabolite of the prodrug 6α-methylprednisolone 21-hemisuccinate (MPS).¹ It transactivates glucocorticoid and mineralocorticoid receptors in a reporter assay using CV-1 cells (EC50s = 2.92 and 2.31 nM for the human receptors, respectively). Methylprednisolone (40 mg/kg) reduces endotoxin-induced complement activation in rabbits.² It induces T cell apoptosis and reduces the number of T cell spinal cord infiltrates in a rat model of experimental autoimmune encephalomyelitis (EAE) when administered at a dose of 50 mg/kg.³ It decreases the number of reactive spinal astrocytes, improves proprioceptive limb placing and coordination, and reduces spinal edema and the number of spinal necrotic cells in a rat model of spinal crush injury.⁴ Formulations containing methylprednisolone have been used in the treatment of immune and autoimmune disorders, such as rheumatoid arthritis, systemic lupus erythematosus, psoriasis, corneal ulcers, ulcerative colitis, and allergies, among others.