Effect Of Gatifloxacin On The Pharmacokinetics Of Aminophylline In Patients With Chronic Obstructive Pulmonary Disease

Objective To study quantitively the effect of gatifloxacin capsule on the pharmacokinetics of aminophylline(Ami) in patients with COPD and to offer clinic pharmacological inference of the concomitant of Ami with gatifloxacin.Methods All 10 patients were given Ami orally 200mg, q8h for 3d, then added gatifloxacin 400mg, q24h from d4-d8. lml of blood was phlebotomized after 0h, 0.5h, 1h, 2h, 4h, 6h, 8h, 10h and 12h when the drugs were adminstered. The serum concentration of theophylline was determined by fluorescence polarization immunoassag. The compartmentmodel and pharmacokinetic parmeters were calculated by DAS software.Results The concentration-time curve of theophylline was fit to one-compartment model. The concentrations of theophylline on every point in concentration-time curve were lower after coadminstering aminophylline with gatifloxacin than those values of administering aminophylline alone. The value of Cmax was decreased from 10.37μg/ml to 10.20 μg/ml, the rate was 1.64%.The value of Tmax was decreased from 1.55h to 1.15h, the rate was 25.80%.The value of T_1/2 was proloned from 9.35hl to 11.09h , 18.61% was increased.The value of AUC was increased from 148.34 μg/ml.h to 157.90 μg/ml. h, the rate was 6.44%.The value was decreased from 0.07 L/h to 0.06 L/h, the rate was 14.29%. The value of V_d was increased from 0.46L/kg to 0.47L/kg, the rate was 2.17%. The value of CL was not been effected.