Clinical Pharmacology: Prednisone is inactive until metabolized to prednisolone. Hepatic conversion is rapid and complete. Plasma half-life of prednisone/prednisolone is 3–4 hours, but the biologic effect lasts 18–36 hours. Rayos is a delayed release brand of prednisone whose pharmacokinetic profile is delayed about 4 hours compared to immediate release prednisone. It is more expensive than immediate release prednisone. Dexamethasone has almost no mineralocorticoid effect. It is more potent than prednisone/prednisolone but more difficult to titrate clinically. Depot injection preparations, either intraarticularly or intramuscularly, provide low plasma concentrations of steroid for 2–4 weeks.
Although side effects to steroids can be serious, your child should not stop taking steroids if side effects first appear. You doctor has many ways to manage the side effects, including lowering the amount of steroids your child takes and changing the way your child takes the steroids. Make sure your doctor makes changes to try to decrease side effects. Try out these changes before you and your child decide to stop taking steroids—though the side effects may be difficult, remember that steroids are the only medicines known to improve strength in people with Duchenne.