Depo-Medrol is the Correct Answer
Depo-Medrol (methylprednisolone acetate) is a suspension formulation specifically designed for intramuscular injection and is contraindicated for intravenous use. 1
Formulation Characteristics
Depo-Medrol contains methylprednisolone acetate as a suspension with excipients including polyethylene glycol 3350 (28 mg/mL) and myristyl-gamma-picolinium chloride (0.189 mg/mL), which make it unsuitable for IV administration 1
The suspension formulation is available in 80 mg/mL strength and is approved for intramuscular, intra-articular, soft tissue, or intralesional injection routes only 1
Why Not Intravenous
The particulate nature of methylprednisolone acetate and its excipients pose serious risks if administered intravenously, including potential embolization and vascular complications 2, 3
Polyethylene glycol, a major component of Depo-Medrol, has been associated with cardiovascular, hepatic, respiratory, and CNS toxicity when inappropriately administered 2
The myristyl-gamma-picolinium chloride (miripirium) preservative can be neurotoxic and is not appropriate for IV administration 2, 3
Clinical Applications
Depo-Medrol has been used successfully in rheumatologic conditions, with studies showing 120 mg intramuscular injections every 3 weeks for polymyalgia rheumatica achieving disease control with lower cumulative steroid exposure compared to oral formulations 4, 5
The intramuscular route provides sustained release, allowing for less frequent dosing compared to oral or IV formulations 5
Other Formulations for Comparison
- Medrol is the oral tablet formulation of methylprednisolone (not a suspension)
- Solu-Medrol is methylprednisolone sodium succinate, a water-soluble formulation specifically designed for IV or IM injection (not a suspension)
- Depakote is not a corticosteroid—it is valproic acid, an anticonvulsant medication