The Influence of Multiple Oral Doses of Zileuton on the Steady-State Pharmacokinetics of Sulfasalazine and its Metabolites, Sulfapyridine and N-Acetylsulfapyridine

Abstract

The effects of zileuton (Abbott-64077) on the pharmacokinetics of sulfasalazine (SASP) and its metabolites, sulfapyridine (SP) and N-acetylsulfapyridine (ASP), were studied in a randomised double-blind placebocontrolled study enrolling 14 healthy male volunteers. All subjects received SASP 1g every 12 hours for 8 days and zileuton 800mg or placebo administered twice daily from day 4 to day 8 inclusive. Coadministration of zileuton did not significantly affect the area under the plasma concentration-time curve, the maximum (C_max) or minimum (C_min) plasma concentration and the time to Cmax of SASP, SP or ASP. Likewise, zileuton did not modify the terminal elimination half-life of SASP. It is concluded that coadministration of zileuton 1.6 g/day has no significant effects on the pharmacokinetics of SASP 2 g/day or its metabolites, SP and ASP.