Factors Influencing Cyclosporine Trough and Two-Hour Post-dose Concentrations in Children with Idiopathic Nephrotic Syndrome.

OBJECTIVE

To determine the cyclosporine trough (C) and two-hour post-dose concentrations (C) in children with nephrotic syndrome (NS) and study the factors influencing them.

METHODS

In this ambispective cohort study, children with NS (including frequently relapsing, steroid-dependent and steroid-resistant nephrotic syndrome) on cyclosporine therapy were enrolled. Clinical and laboratory data were recorded. C and C were estimated using liquid chromatography mass spectrometry.

RESULTS

Among 27 patients with a mean (SD) age of 6.4 (4.1) years, the median (Q1, Q3) of C and C were 114.8 (86.1, 186.3) ng/mL and 661.6 (442.1, 884.6) ng/mL, respectively. At a mean (SD) cyclosporine dose of 4.1 (0.8) mg/kg/day, 12 (44%) patients had C above and 4 (15%) below the therapeutic range (80-120 ng/mL). C levels were outside the recommended ranges in 17 (63%) children, within range in 7 (26%), and below in 3 (11%). Capsule users had higher C than syrup users. Amlodipine therapy was associated with higher C levels.

CONCLUSION

Nearly half the children had C and C levels outside the therapeutic range. Dosage form and amlodipine influenced C, not C concentrations.