PLASMA PROTEIN-BINDING PARAMETERS OF PREDNISOLONE IN IMMUNE DISEASE PATIENTS RECEIVING LONG-TERM PREDNISONE THERAPY

  • 1 January 1981
    • journal article
    • research article
    • Vol. 97  (4) , 487-501
Abstract
Prednisone [PN] and prednisolone [PNL] bind in plasma to albumin and transcortin. In an attempt to determine whether PN side-effects and/or type of disease correlated with PNL plasma protein binding, multiple plasma samples from 17 patients (3 asthma, 8 SLE [systemic lupus erythematosus], 3 rheumatoid arthritis, 2 progressive systemic sclerosis, 1 polyarteritis nodasa) receiving long-term PN therapy were monitored during an interval between 2 PNL doses. PN plasma protein binding was nonlinear and exhibited large intrapatient and interpatient variability. For the group, mean association constants of the PNL-albumin complex and the PNL-transcortin complex were 2.3 .times. 103 M-1 and 2.9 .times. 107 M-1, with coefficients of variation of 82% and 127%, respectively. SLE patients tended to have lower mean PNL association constants for albumin and transcortin than did other patients. The presence of corticosteroid side-effects did not correlate with PNL plasma protein-binding parameters. The wide PNL-free fraction range noted in plasma from patients who achieved comparable total PNL plasma concentrations implies that uniform PN dose administration will not lead to a predictable clinical response.