Pharmacokinetics of flufenamic acid in man

Flufenamic acid (200 mg) was administered in the form of a soft capsule to 8 young healthy volunteers after an overnight fast. The drug was absorbed irregularly and plasma curves showed large variation. Peak plasma concentrations varied strongly (6-20 micrograms/ml) but were usually reached within 1.5 h. The terminal elimination half-life is long (5-22 h) and the total body clearance is low (80-150 ml/min) causing long mean residence time (4-28 h). The total apparent volume of distribution is much larger than the total body water volume. The large intersubject variations led to the conclusion that mean values of the pharmacokinetic parameters of flufenamic acid after oral administration are not useful for practical purposes.