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Influence of ruminal distribution on norfloxacin pharmacokinetics in adult sheep
Author(s) -
González F.,
Andrés M. I. San,
Nieto J.,
Andrés M. D. San,
Waxman S.,
Vicente M. L.,
Lucas J. J.,
Rodríguez C.
Publication year - 2001
Publication title -
journal of veterinary pharmacology and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.527
H-Index - 60
eISSN - 1365-2885
pISSN - 0140-7783
DOI - 10.1046/j.1365-2885.2001.00334.x
Subject(s) - rumen , bioavailability , pharmacokinetics , zoology , chemistry , norfloxacin , plasma concentration , oral administration , distribution (mathematics) , pharmacology , biology , biochemistry , antibiotics , mathematics , mathematical analysis , ciprofloxacin , fermentation
González, F., San Andrés, M. I., Nieto, J., San Andrés, M. D., Waxman, S., Vicente, M. L., Lucas, J. J., Rodríguez, C. Influence of ruminal distribution on norfloxacin pharmacokinetics in adult sheep J. vet. Pharmacol. Therap. 24, 241–245. Norfloxacin (NF) ruminal distribution after intravenous (i.v.), intramuscular (i.m.) and oral (p.o.) administration was determined in order to assess the influence of the rumen on the pharmacokinetic behaviour of NF in sheep. Norfloxacin concentrations in rumen were detected after i.v. and i.m. administrations between 4 and 48 h in all animals studied. The experimental distribution ratios after i.v. and i.m. administration expressed as area under the concentration–time curve ratios AUC rumen / AUC plasma were 0.24 and 0.39, respectively, and thus lower than corresponding predicted value of 5.06. Apparently, drug persisted in the rumen content longer than in plasma. The experimental mean residence time ratios MRT rumen / MRT plasma after i.v. and i.m. administrations were 2.33 and 1.66, respectively. After p.o. administration, NF concentrations in the rumen content were extremely high compared with the respective plasma concentrations, resulting in mean peak concentrations ratio C max‐rumen / C max‐plasma of 383.66 and AUC rumen / AUC plasma experimental ratio of 402.32. This value was considerably higher (≈79 fold) than the predicted distribution ratio of 5.06. Our results suggest that the limited p.o. bioavailability of NF in ruminants could not be attributed to ruminal degradation.