Influence of Ibuprofen on the pharmacokinetics of isoniazid

The influence of ibuprofcn (400 mg urally) on the pharmacokinetics of isoniazid (500 mg orally) was evaluated in healthy human subjects (n = 30). Subjects participated in a two way crossover trial, the first dosing condition was isoniazid alone (control), and the second dosing condition was ibuprofen with isoniazid. The concentrations of isoniazid from the serum samples were determined by HPLC. The pharmacokinetic parameters show a significant (P.<0.05) increase in the area under the serum concentration/time curve (AUC) in both fast and slow acetylators of isoniazid, with a significant increase in the maximum serum concentration (C(max)) of isoniazid (only in slow acetylators with no effect on fast acetylators), a significant increase in the elimination half-life (t (1/2)), and the time for the maximum drug concentration (T(max)) (only in fast acetylators with no effect on slow acetylators).