title: Double-blind evaluation of the safety and pharmacokinetics of multiple oral once-daily 750-milligram and 1-gram doses of levofloxacin in healthy volunteers.
abstract: The safety and pharmacokinetics of once-daily oral levofloxacin in 16 healthy male volunteers were investigated in a randomized, double-blind, placebo-controlled study. Subjects were randomly assigned to the treatment (n = 10) or placebo group (n = 6). In study period 1, 750 mg of levofloxacin or a placebo was administered orally as a single dose on day 1, followed by a washout period on days 2 and 3; dosing resumed for days 4 to 10. Following a 3-day washout period, 1 g of levofloxacin or a placebo was administered in a similar fashion in period 2. Plasma and urine levofloxacin concentrations were measured by high-pressure liquid chromatography. Pharmacokinetic parameters were estimated by model-independent methods. Levofloxacin was rapidly absorbed after single and multiple once-daily 750-mg and 1-g doses with an apparently large volume of distribution. Peak plasma levofloxacin concentration (Cmax) values were generally attained within 2 h postdose. The mean values of Cmax and area under the concentration-time curve from 0 to 24 h (AUC0-24) following a single 750-mg dose were 7.1 microg/ml and 71.3 microg x h/ml, respectively, compared to 8.6 microg/ml and 90.7 microg x h/ml, respectively, at steady state. Following the single 1-g dose, mean Cmax and AUC0-24 values were 8.9 microg/ml and 95.4 microg x h/ml, respectively; corresponding values at steady state were 11.8 microg/ml and 118 microg x h/ml. These Cmax and AUC0-24 values indicate modest and similar degrees of accumulation upon multiple dosing at the two dose levels. Values of apparent total body clearance (CL/F), apparent volume of distribution (Vss/F), half-life (t1/2), and renal clearance (CL[R]) were similar for the two dose levels and did not vary from single to multiple dosing. Mean steady-state values for CL/F, Vss/F, t1/2, and CL(R) following 750 mg of levofloxacin were 143 ml/min, 100 liters, 8.8 h, and 116 ml/min, respectively; corresponding values for the 1-g dose were 146 ml/min, 105 liters, 8.9 h, and 105 ml/min. In general, the pharmacokinetics of levofloxacin in healthy subjects following 750-mg and 1-g single and multiple once-daily oral doses appear to be consistent with those found in previous studies of healthy volunteers given 500-mg doses. Levofloxacin was well tolerated at either high dose level. The most frequently reported drug-related adverse events were nausea and headache.
authors.affiliation: The R. W. Johnson Pharmaceutical Research Institute, Raritan, New Jersey 08869, USA.
authors.forename: S C
authors.initials: SC
authors.lastname: Chien
authors.forename: F A
authors.initials: FA
authors.lastname: Wong
authors.forename: C L
authors.initials: CL
authors.lastname: Fowler
authors.forename: S V
authors.initials: SV
authors.lastname: Callery-D'Amico
authors.forename: R R
authors.initials: RR
authors.lastname: Williams
authors.forename: R
authors.initials: R
authors.lastname: Nayak
authors.forename: A T
authors.initials: AT
authors.lastname: Chow
mesh_terms: D000293:Adolescent; D000328:Adult; D000890:Anti-Infective Agents / Q000008:administration & dosage / Q000009:adverse effects* / Q000493:pharmacokinetics*; D019540:Area Under Curve; D004311:Double-Blind Method; D006207:Half-Life; D006801:Humans; D064704:Levofloxacin; D008297:Male; D008875:Middle Aged; D015242:Ofloxacin / Q000008:administration & dosage / Q000009:adverse effects* / Q000493:pharmacokinetics*
chemical_list: D000890:Anti-Infective Agents; D064704:Levofloxacin; D015242:Ofloxacin