⚠️ Not interchangeable. Depo-Medrol (acetate) is a suspension and must never be given IV. Solu-Medrol (sodium succinate) is water-soluble and intended for IV/IM; it does not provide a depot effect.
Dimension Methylprednisolone Acetate (Depo-Medrol) Methylprednisolone Sodium Succinate (Solu-Medrol)
Formulation & Solubility Suspension; poorly water-soluble “depot.” Solution after reconstitution; highly water-soluble.
Primary Routes IM depot; intra-articular; intralesional; soft-tissue.
Not for IV.		 IV (preferred for rapid effect) or IM.
Onset Intra-articular onset ≈ 1 week; prolonged local effect. Systemic effect within ≈ 1 hour after IV.
Duration Depot effect days–weeks (often 1–5 wks). HPA axis suppression 4–8 days after a single 40–80 mg IM dose reported. Rapid elimination; near-complete excretion ≈ 12 h. Redose q4–6 h if constant high levels needed.
PK Notes Slow absorption; IM absorption half-time ≈ 69 h; bioavailability ≈ 42.7%. Succinate ester hydrolysis half-life ≈ 4.1 min → fast release of active drug; IV bioavailability cited ≈ 43.6% after conversion.
Typical Use Cases
  • Intra-articular: OA synovitis, RA, gout.
  • Intralesional: keloids, alopecia areata, DLE, lichen planus.
  • Soft tissue: bursitis, tendonitis, epicondylitis.
  • Systemic depot when infrequent dosing desired.
  • Acute asthma, severe allergy/anaphylaxis.
  • Shock/CNS trauma; MS exacerbations.
  • High-dose IV “pulse” therapy (e.g., 30 mg/kg over ≥30 min).
Preparation Ready-to-use suspension; shake well. Available 20, 40, 80 mg/mL. Powder for reconstitution; Act-O-Vial sizes (40 mg to 2 g). Some vials contain benzyl alcohol (avoid in neonates). Administer slow IV push/infusion.
Representative Dosing Intra-articular:
  • Large joints: 20–80 mg
  • Medium: 10–40 mg
  • Small: 4–10 mg
Repeat every 1–5 weeks per response. 		Emergency IV:
  • Adults: 125 mg IV
  • Peds: ~2 mg/kg IV
  • Pulse: 30 mg/kg IV over ≥30 min
Safety Keys Never IV. Suspension particles risk embolic events if given IV. Rapid systemic exposure; monitor BP, glucose, electrolytes. Not suitable for depot therapy.