Pharmacokinetic study of mizoribine in child-onset glomerulonephritis.

BACKGROUND

Mizoribine (MZR) has been successfully used without serious adverse effects in patients with various types of glomerulonephritis, but there are only a few pharmacokinetic studies of MZR. The purpose of the present paper was to report the results of a pharmacokinetic study of MZR in child-onset glomerulonephritis.

METHODS

Nine patients were enrolled. MZR was administered orally at 60-300 mg/day (3.0-8.4 mg/kg bodyweight/day) divided in one or two daily doses. Blood samples were collected 7-10 times before and after drug administration. Urine samples were also collected during the blood sampling periods. Twenty-three concentration curves of MZR were analyzed in the present study. Pharmacokinetic parameters for mizoribine were estimated using concentration-time profiles. The non-parametric Spearman correlation coefficient was calculated to determine significant associations between variables. P < 0.05 was considered significant.

RESULTS

The obtained pharmacokinetic values at a dose of 3.36 +/- 1.91 mg/kg bodyweight were as follows: time to peak serum MZR concentration, 2.94 +/- 0.82 h; peak serum MZR concentration, 1.59 +/- 1.16 microg/mL; half-life, 1.96 +/- 0.92 h; area under the serum MZR concentration-time curve from time zero to infinity, 9.36 +/- 6.58 microg h/mL; volume of the distribution of MZR at a steady state, 2.03 +/- 0.80 L/kg; and rate of urinary excretion of MZR, 49.1 +/- 18.7%.

CONCLUSIONS

The parameters estimated in the present study may be useful for the MZR treatment of patients with child-onset glomerulonephritis.