High-dose systemic corticosteroids for idiopathic inflammatory myopathies (excluding inclusion body myositis)

Managing idiopathic inflammatory myopathies requires specialist supervision and people usually need lifelong treatment and monitoring. First-line therapy for these conditions (except inclusion body myositis [IBM]) involves high-dose oral corticosteroids or pulse intravenous methylprednisolone, if symptoms are severe. Pulse intravenous methylprednisolone may be preceded by intravenous immunoglobulin (IVIg) therapy in severe cases (eg necrotising autoimmune myopathy [NAM]); see IVIg therapy for severe idiopathic inflammatory myopathies. Oral corticosteroids are usually used in combination with a corticosteroid-sparing conventional synthetic disease-modifying antirheumatic drug (csDMARD).

If pulse intravenous methylprednisolone is indicated for treatment of severe idiopathic inflammatory myopathy, use:

methylprednisolone sodium succinate 0.5 to 1 g intravenously, over 1 hour, daily for 3 days, then switch to oral prednisolone (or prednisone) as below. methylprednisolone sodium succinate methylprednisolone methylprednisolone

If high-dose oral corticosteroids are indicated for treatment of idiopathic inflammatory myopathy, use:

prednisolone (or prednisone) 1 mg/kg up to 75 mg orally, daily in the morning for 6 weeks, then reduce daily dose by 5 mg every 2 weeks to 25 mg daily, then reduce further according to response and tolerability. prednis ol one prednis(ol)one prednis(ol)one

If the patient responds rapidly or has adverse effects, high-dose oral corticosteroids can be tapered faster under expert supervision. Significant adverse effects limit the use of long-term, high-dose oral corticosteroids; see Specific considerations for use of systemic corticosteroids for specific considerations for systemic corticosteroids, and advice on how to identify and minimise complications (eg bone density loss).