A comparison of plasma methylprednisolone concentrations following intra-articular injection in patients with rheumatoid arthritis and osteoarthritis.

Plasma concentrations of methylprednisolone following intra-articular injection were measured in rheumatoid arthritis and osteoarthritis patients. While substantial plasma concentrations were seen in both groups of patients there was no significant difference in the rate or extent of absorption of methylprednisolone from osteoarthritic or rheumatoid knees. This study suggests that it is the dissolution rate of the steroid formulation rather than the characteristics of the synovial membrane which determine rate and extent of systemic absorption of methylprednisolone after intra-articular injection.