SINGLE-DOSE PHARMACOKINETIC STUDY OF CIPROFLOXACIN AND FLEROXACIN IN HEALTHY ADULT NIGERIAN VOLUNTEERS

The kinetics of absorption, distribution and elimination of ciprofloxa cin and fleroxacin (following an intravenous dose of 200 mg), were eva luated in 24 adult healthy male Nigerian volunteers. Appropriate mathe matical models were applied with the aid of a microcomputer software p rogram for the estimation of the basic pharmacokinetic parameters. App ropriate statistical tests and profiles formed the basis for accepting or rejecting a proposed model. For parametric comparisons between the profile of the two drugs, the null hypothesis of no difference in the ir pharmacokinetic profile was proposed. All statistical tests were pe rformed at a significance level of 95% (alpha = 0.05) and the 95% conf idence level was determined where appropriate. Additionally, the model -independent or stochastic method of analysis was also employed in the pharmacokinetic evaluation of the blood level data. The parametric es timates obtained from both methods were compared. The plasma eliminati on half-life (t(1/2)) was estimated as 13.8 +/- 5.5 h for fleroxacin a nd 7.5 +/- 4.0 h for ciprofloxacin; the maximal plasma concentration ( C-max) was 0.8 +/- 0.3 and 2.3 +/- 1.0 mg/l for fleroxacin and ciprofl oxacin, respectively, whilst the volume of distribution (V-d) was 2.5 +/- 1.6 and 0.4 +/- 0.3 liters/kg for fleroxacin and ciprofloxacin, re spectively. 71 and 70% of unchanged drug were excreted in urine for fl eroxacin and ciprofloxacin, respectively. With respect to comparative values, the results confirmed trends already observed in the literatur e, particularly as regards the t(1/2). However, for fleroxacin there w as a significant deviation from the literature trends with respect to V-d, C-max and AUG. The results also confirmed earlier findings, advoc ating a once-daily dosage schedule for fleroxacin also in the Negroid population.