Modifications in cyclosporine (CsA) microemulsion blood concentrations by olestra.
OBJECTIVE: Determine whether olestra alters the absorption of cyclosporine microemulsion in pediatric renal transplant recipients. DESIGN: Prospective, open-label, crossover pharmacokinetic study. SETTING: General clinical research center in a university medical setting providing tertiary care. PARTICIPANTS: Seven pediatric-adolescent renal transplant recipients, ages 9 to 18, 5 to 24 months post-transplant with mean serum creatinine of 0.9 mg/dL (range, 0.7-1.6 mg/dL). METHODOLOGY: Patients participated in 2 study periods: 1. Patients were given their usual dose of Neoral (Novartis Pharmaceuticals Corporation, East Hanover, NJ) without olestra, 2. patients were given their usual dose of Neoral combined with 0.35 g/kg (maximum of 16 g of olestra or approximately 2 ounces of Lays WOW [Frito Lay, Plano, TX] potato chips). The 2 study periods were separated by a minimum 7-day washout period. CsA blood concentrations were obtained at 1, 2, 3, 4, 6, 8, and 12 hours after drug administration. RESULTS: Each patient in the study had a consistent decrease in area under the curve (AUC) when given olestra along with their usual dose of Neoral, compared with giving Neoral alone (5,018 ng*hr/mL versus 4,086 ng*hr/mL; P <.001). There also was a decrease in maximum concentration (Cmax) when Neoral was given with olestra compared with giving Neoral alone (1,202 ng/mL versus 876 ng/mL; P =.015). There was no statistical difference in the mean elimination rate or the trough values for both regimens (half-life 4.767 hours versus 4.771 hours and trough levels of 143 ng/mL versus 124 ng/mL). CONCLUSION: Olestra decreases total CsA exposure in pediatric renal transplant recipients. The noted decrease in AUC was not adequately predicted by CsA trough values which could lead to rejection episodes in the clinical setting.