Thus, the physiological range of GCs is monitored by the  negative feedback loop GCs exert on any portion of the HPA axis. Methylprednisolone structurally and functionally mimics endogenous corticoids and will act upon the HPA axis in a similar fashion. Pharmacokinetics
Methylprednisolone is approved for oral and parenteral administration. Methylprednisolone (Medrol) for oral administration is available in a tablet formulation in 2 mg, 4 mg, 8 mg, 16 mg or 32 mg strengths. Both methylprednisolone acetate (Depo-Medrol) and methylprednisolone succinate (Solu-Medrol) are approved for intramuscular injection. Depo-Medrol is additionally approved for intralesional, intra-articular, and soft tissue injections. Depo-Medrol is available as sterile aqueous solution in 20 mg/mL, 40 mg/mL, or 80 mg/mL strengths. Solu-Medrol is the only derivative of methylprednisolone that is approved for intravenous infusion, as the sterile powder is soluble in water and can be mixed with a diluent. Strengths vary from 40 mg to 2g.Synthetic glucocorticoids are similar to endogenous steroids in metabolism, but differ in affinity for glucocorticoid and mineralocorticoid receptors, affinity for protein-binding, rate of elimination, and metabolic products.Oral methylprednisolone is readily absorbed from the gastrointestinal tract with a bioavailability of 89.9%. In contrast to endogenous GCs, methylprednisolone does not bind to the glycoprotein transcortin (corticosteroid binding globulin, CBG) but does have moderate protein binding to albumin. Thus, pharmacokinetics of methylprednisolone is linear and show no dose dependency. Patients exhibiting low albumin concentrations are at risk for adverse effects during glucocorticoid therapy.
Methylprednisolone (Depo-Medrol, Medrol, Solu-Medrol) is a synthetic glucocorticoid, primarily prescribed for its anti-inflammatory and immunosuppressive effects. It is either used at low doses for chronic illnesses or used concomitantly at high doses during acute flares. Methylprednisolone and its derivatives can be administered orally or parenterally.Regardless of route of administration, methylprednisolone integrates systemically as exhibited by its effectiveness to quickly reduce inflammation during acute flares. It is associated with many adverse reactions that require tapering off the drug as soon as the disease is under control. Serious side effects include iatrogenic Cushings Syndrome, hypertension, osteoporosis, diabetes, infection, and skin atrophy.Chemically, methylprednisolone is a synthetic pregnane steroid hormone derived from hydrocortisone and prednisolone. It belongs to a class of synthetic glucocorticoids and more generally, corticosteroids. It acts as a mineralocorticoid and glucocorticoid receptor agonist. In comparison to other exogenous glucocorticoids, methylprednisolone has a higher affinity to glucocorticoid receptors than to mineralocorticoid receptors. Glucocorticoids name was derived after the discovery of their involvement in regulating carbohydrate metabolism. The cellular functions of glucocorticoids, such as methylprednisolone, are now understood to regulate homeostasis, metabolism, development, cognition, and inflammation. They play a critical role in adapting and responding to environmental, physical and emotional stress.Methylprednisolone was first synthesized and manufactured by The Upjohn Company (now Pfizer) and FDA approved in the United States in October 1957. In 2019, it was the 161st most commonly prescribed medication in the United States, with more than 3 million prescriptions.