Comparative Pharmacokinetics of Levofloxacin in Healthy Volunteers and in Patients Suffering from Typhoid Fever

The aim of this study was to characterize the effect of typhoid fever on pharmacokinetic parameters of levofloxacin (LF) and compare the pharmacokinetic parameters of the said antibiotic in healthy human volunteers and patients with typhoid fever. Total of 12 subjects were divided into two groups “A” (healthy volunteers) and “B” (typhoid patients). Single oral dose of LF 500 mg was given and 5 mL of blood was collected from each subject at 0, 0.25, 0.5, 1, 2, 3, 6, 12, 24, 36 and 72 h. Plasma concentrations of LF were measured by HPLC. Pharmacokinetic parameters were calculated from plasma concentration-time data by using MW/PHARM pharmacological analysis. In healthy volunteers, the average pharmacokinetic parameters were as Cmax (6.79 μg/mL), Tmax (1.84 h), T½ (10.03 h), Ka (2.23 h-1), AUC (110.09 μgh/mL), Vd (85.84 L), Cl (4.57 L/h) and in typhoid patients were Cmax (6.90 μg/mL), Tmax (1.82 h), T½ (9.42 h), Ka (2.21 h-1), AUC (105.55 μgh/mL), Vd (64.31 L), Cl (4.75 L/h). The difference between pharmacokinetic parameters of LF in healthy human volunteers and typhoid patients was calculated by using unpaired t-test. As the p-value in case of all pharmacokinetic parameters was more than 0.05, the difference between pharmacokinetic parameters in both healthy human volunteers and typhoid patients was insignificant. It is concluded that there is no need to adjust the dose of LF in typhoid patients.