Abstract

The apparent absence of established dosage regime for medicating tilapia with fluoroquinolones in the country necessitated investigating the absorption and tissue distribution of Ciprofloxacin, since dosage regimes conform to accepted standards of pharmacokinetic studies.Ciprofloxacin pharmacokinetic studies were conducted on 76 hybrid tilapia weighing between 100 and 200 grams divided into two groups with each subjected to bath administration of ciprofloxacin at two different concentrations.  The fishes in groups 1 and 2 were exposed by bath to 50 mg and 25 mg respectively of ciprofloxacin per litre of water. Tissue and blood samples were collected at 0.5h, 1h, 2h, 4h, and 8h during medication and drug withdrawal at 24h, 48h, and 72h, to quantify their ciprofloxacins by Enzyme Linked Immunosorbent Assay (ELISA).Peak serum concentration of ciprofloxacin in group 1 was 2,251±877 µg/L at 8 h while for group 2; it was 2,226±174 µg/L at 4 h exposure time.  The t- test comparing the means of the groups 1 and 2 showed that there was no significant statistical difference (p > 0.05) on group sera, liver and kidney, except skeletal muscle ciprofloxacin concentration.  The elimination half-lives in groups 1 and 2 were determined on serum ciprofloxacin values, after withdrawal of drug and were 27.75 h and 31.8 h, with rate constant of elimination being 0.025 h^-1 and 0.022 h^-1 respectively. Sera Area under Curve, {AUC _(0.5-8h)} values were 12,159.3 and 13,194 µg/L respectively with 92.2% correlation. Prolonged high ciprofloxacin concentration was observed in tilapia skeletal muscle.High correlation in sera AUC values is suggestive of similar therapeutic action hence; it is cheaper to use the lower dose. While a prolonged high ciprofloxacin concentration in skeletal muscle has therapeutic advantage for fish, it remains a public health concern because the muscle is an edible tissue.

Keywords: Bath, Ciprofloxacin, ELISA, Pharmacokinetics, Tilapia