The effect of diosmin on the pharmacokinetics of fexofenadine in healthy human volunteers.

1. Diosmin (DSN) has been found to possess P-glycoprotein (P-gp) inhibition activity in vitro and in vivo in rats, which may have potential to cause P-gp-mediated interactions in humans. The purpose of the present study was to investigate the effect of DSN on pharmacokinetics of fexofenadine (FEX) in healthy human volunteers. 2. An open-label, two-period, sequential study was conducted in 12 healthy male volunteers. A single dose of FEX 120 mg was administered to volunteers during control and treatment phases. A single dose of DSN 500 mg was administered to volunteers daily for period of 10 days. The blood and urine samples were collected at predetermined time intervals after FEX dosing and analyzed by LC-MS/MS. 3. Treatment with DSN significantly increased the peak maximum plasma concentration (C