High-dose methylprednisolone sodium succinate (pulse therapy) in the treatment of renal disease: plasma and urine concentrations.

Methylprednisolone hemisuccinate (MPS) and methylprednisolone (MP) concentrations in plasma and urine were monitored in renal transplant and glomerulonephritis patients who were given i.v. infusions of 0.5 g or 1 g of MPS. A marked individual variation of peak plasma levels of both MPS and MP was observed after the same dose and MPS disappeared from plasma more rapidly than MP. Their clearances from the circulation, however, did not appear to be significantly influenced by the peak plasma levels of the drug, creatinine clearance, administration of previous pulses of MPS or the urinary excretion of unconjugated MPS and MP. Even in patients with profoundly reduced renal function, no accumulation of the drug was apparent when repeated doses of MPS were administered at 48-h intervals.