Lumiracoxib: Pharmacokinetic and pharmacodynamic profile when coadministered with fluconazole in healthy subjects

This two-way crossover study evaluated the effect of fluconazole on the pharmacokinetics and selective COX-2 inhibition of lumiracoxib. Thirteen healthy subjects were randomized to fluconazole (day 1: 400 mg, days 2-4: 200 mg) or no drug. On day 4, all subjects received a single dose of lumiracoxib (400 mg). Lumiracoxib pharmacokinetics were assessed during the following 48 hours. Thromboxane B, (TxB(2)) inhibition was measured prior to lumiracoxib dosing and 2 hours afterwards. Fluconazole caused a small (18%) but not clinically relevant increase in lumiracoxib mean AUC(0-infinity) but had no effect on lumiracoxib mean C-max. The geometric mean ratio (lumiracoxib plus fluconazole/lumiracoxib alone) for AUC(0-infinity) was 1.19 (90% confidence interval [CI] = 1.12, 1.27) and for C-max was 1.11 (90% CI = 0.98, 1.27). The decrease in TxB(2) from predose was not significantly different for lumiracoxib (11.8%) or lumiracoxib plus fluconazole (7.1%); no correlation between lumiracoxib concentration and TxB(2) decrease was seen. As fluconazole is a strong inhibitor of cytochrome P450 (CYP) 2C9, other CYP2C9 inhibitors are unlikely to affect lumiracoxib pharmacokinetics with clinical relevance, making dosage adjustment unnecessary.