Farmakokinetika oleandomicina primijenjenog samostalno i nakon peroralne primjene askorbinske kiseline trima vrstama ptica.

The influence of ascorbic acid administration via drinking water at a dose of 15 mg/l over a period of 7 days on the pharmacokinetics of oleandomycin in chickens, musk ducks and Japanese quails was investigated. After ascorbic acid oleandomycin elimination, half-life was longer. Oleandomycin bioavailability in chickens and quails after per os application was increased with ascorbic acid. Interspecies differences in oleandomycin body disposition were observed. Lower elimination rate constants were obtained in the musk ducks in comparison with two other species. The volume of distribution (Vss) was larger in quails. In conclusion, ascorbic acid did not change oleandomycin disposition significantly in the treated birds.Istražen je učinak askorbinske kiseline primijenjene u vodi za piće u dozi 15 mg/l u tijeku 7 dana na farmakokinetiku oleandomicina u kokoši, mošusnih pataka i japanskih prepelica. Poluvrijeme eliminacije oleandomicina bilo je duže u ptica tretiranih askorbinskom kiselinom, a bioraspoloživost mu je porasla u kokoši i prepelica nakon peroralne primjene. Opažene su vrsne razlike u raspodjeli oleandomicina. U usporedbi s kokošima i japanskim prepelicama, u mošusnih pataka zabilježene su niže vrijednosti konstanti opsega eliminacije. Volumen raspodjele (Vss) bio je veći u prepelica. Zaključuje se da askorbinska kiselina ne utječe značajno na raspodjelu oleandomicina u tretiranih ptica

Farmakokinetika enrofloksacina u pataka s masnom degeneracijom jetre nakon prisilnog hranjenja

The pharmacokinetics of enrofloxacin (EFC) was investigated in ducks fed with a normal diet, and in force-fed ducks, after a single intravenous (i.v.) and oral (p.o.) administration at doses of 10 mg/kg. Serum concentrations of EFC and ciprofloxacin (as metabolite of EFC) were determined by the HPLC method. The elimination half-lives of EFC after i.v. administration and compartmental pharmacokinetic analysis were 4.62 ± 0.62h and 6.39 ± 2.78 h in healthy and force-fed ducks, respectively. The values of total body clearance were 0.24 ± 0.03 L/h/kg in healthy and 0.18 ± 0.02 L/h/kg in force-fed ducks. The values of the volume of distribution (Vss) were 1.32 ± 0.18 L/kg and 1.31 ± 0.21 L/kg, respectively. After oral administration, maximum serum concentrations were 1.95 ± 0.36 µg/mL reached at 3.67 ± 4.26 h, and 4.25 ± 1.21 µg/mL at 1.25 ± 0.88 h, respectively. The serum concentrations of ciprofloxacin were significantly lower in the force-fed ducks. Longer enrofloxacin residence in force-fed ducks can be expected if compared to normally fed animals.Farmakokinetika enrofloksacina (EFC) primijenjenog intravenski i oralno u dozi od 10 mg/kg istražena je u normalno i prisilno hranjenih pataka. Serumske koncentracije EFC i ciprofloksacina (kao metabolita EFC) bile su određene visokotlačnom tekućinskom kromatografijom. Poluvrijeme izlučivanja EFC nakon i.v. primjene i farmakokinetičke analize po odjeljcima iznosilo je 4,62 ± 0,62 h u zdravih, a 6,39 ± 2,78 h u prisilno hranjenih. Vrijednosti ukupnog klirensa lijeka iz organizma bile su 0,24 ± 0,03 L/h/kg u zdravih i 0,18 ± 0,02 L/h/kg u prisilno hranjenih (šopanih). Vrijednosti volumena raspodjele (Vss) bile su 1,32 ± 0,18 L/kg i1,31 ± 0,21 L/kg. Najveće serumske koncentracije nakon oralne primjene bile su dosegnute nakon 3,67 ± 4,26 h, a iznosile su 1,95 ± 0,36 µg/mL, dok su nakon intravenske primjene bile dosegnute nakon 1,25 ± 0,88 h, a iznosile su 4,25 ± 1,21 µg/mL. Serumske koncentracije ciprofloksacina bile su značajno niže u prisilno hranjenih pataka. Duže zadržavanje enrofloksacina može se očekivati u prisilno hranjenih pataka u odnosu na one normalno hranjen

Raspodjela sulfaklorpirazina u pilića invadiranih vrstom Eimeria tenella.

The control of coccidiosis in chickens is undertaken mainly by administration of anticoccidial drugs. Sulfachloropyrazine-sodium is still used as an effective coccidiocidal compound to treat poultry with clinical signs of coccidiosis. However, its disposition after three days treatment in Eimeria tenella infected chickens has not been well studied. Pharmacokinetics of sulfachlorpyrazine-sodium was investigated in healthy chickens and chickens experimentally infected with E. tenella. Serum and tissue concentrations were determined by HPLC-PDA analysis. The values of absorption half-life (17.24 ± 3.50 h) and time for achievement of maximal serum concentrations Tmax (23.41 ± 3.78 h) of the sulfonamide were significantly higher in infected chickens. An accumulation index of 1.22 ± 0.13 was estimated and significantly higher serum concentrations were observed in E. tenella challenged animals. Significantly higher sulfachloropyrazine-sodium levels were found in the duodenum, caeca and the liver, which suggests that a longer withdrawn time could be expected in infected chickens after three days administration of the anticoccidial agent. The observed changes in sulfachloropyrazine disposition could be attributed to the alteration of the integrity of the intestines and decreased motility of the gastro-intestinal tract during the clinical coccidiosis.Kontrola kokcidioze u pilića pretežito se provodi primjenom protukokcidijskih lijekova (kokcidiostatika). Natrijev sulfaklorpirazin se još uvijek rabi kao učinkovit kokcidiocidni sastojak za liječenje peradi s kliničkim znakovima kokcidioze. Ipak, njegova raspodjela nakon tri dana liječenja nije dovoljno istražena u pilića zaraženih vrstom Eimeria tenella. Farmakokinetika natrijeva sulfaklorpirazina u ovom je radu istražena u zdravih i pokusno invadiranih pilića parazitom E. tenella. Njegove koncentracije u serumu i tkivima bile su određivane metodom HPLC-PDA. Vrijednosti poluvremena apsorpcije (17,24 ± 3,50 h) i vremena za postizanje najvećih koncentracija u serumu Tmax (23,41 ± 3,78 h) bile su značajno veće u zaraženih pilića. Procijenjeni akumulacijski indeks bio je 1,22 ± 0,13, a značajno veće serumske koncentracije bile su ustanovljene u zaraženih životinja. Značajno veće razine sulfaklorpirazina bile su dokazane u dvanaesniku, slijepim crijevima i jetri što govori da se može očekivati duže vrijeme izlučivanja u zaraženih pilića nakon trodnevne primjene antikokcidijske tvari. Ustanovljene promjene u raspodjeli sulfaklorpirazina mogu se pripisati promjeni integriteta crijeva i smanjenom motilitetu želučano-crijevnog sustava kod kliničke kokcidioze

Usporedba određenih hematoloških pokazatelja među trima vrstama porodice Columbidae.

Investigations into some haematological values in birds from three Columbidae species e.g. pigeons, (Columba livia domestica), collared doves (Streptopelia decaocto) and African collared doves, (Streptopelia roseogrisea) have been performed. In all three species, high haemoglobin concentrations, and respectively high red blood cell counts were observed. In S. decaocto the red blood cell count was extremely high, corresponding to the high haemoglobin levels. RBC values in both Streptopelia species were significantly higher than in domestic pigeons. Higher white blood cell counts were present in freely living collared doves versus both species living in captivity. The heterophils/lymphocytes ratio in African collared doves was the highest − 1.05, followed by the ratios of collared doves and domestic pigeons.Provedeno je istraživanje hematoloških vrijednosti triju vrsta ptica porodice Columbidae, i to goluba (Columba livia domestica), gugutke (Streptopelia decaocto) i sahelske gugutke (Streptopelia roseogrisea). U sve tri vrste ustanovljena je velika koncentracija hemoglobina i velik broj crvenih krvnih stanica. U gugutke je broj eritrocita bio iznimno velik, i odgovarao je velikoj razini hemoglobina. Broj eritrocita bio je u obje vrste roda Streptopelia veći nego u goluba. Veći broj bijelih krvnih stanica ustanovljen je u slobodno živućih gugutki u odnosu na one držane u zatočeništvu. Omjer heterofila i limfocita u sahelske gugutke bio je najveći (1,05), srednji u gugutke, a najmanji u goluba

Integration of Pharmacokinetic and Pharmacodynamic Indices of Marbofloxacin in Turkeys

Fluoroquinolones are extensively used in the treatment of systemic bacterial infections in poultry, including systemic Escherichia coli bacillosis, which is a common disease in turkey flocks. Marbofloxacin has been licensed for use in various mammalian species, but not as yet for turkeys, although its kinetic properties distinguish it from other fluoroquinolones. For example, the longer half-life of marbofloxacin in many animal species has been appreciated in veterinary practice. It is generally accepted that, for fluoroquinolones, the optimal dose should be estimated on the basis of the pharmacokinetic (PK) and pharmacodynamic (PD) characteristics of the drug under consideration. Knowledge of these specific data for the target animal species allows the establishment of an integrated PK-PD model that is of high predictive value. In the present study, the antibacterial efficacy (PD indices) against a field isolate of Escherichia coli O78/K80 was investigated ex vivo following oral and intravenous administration of marbofloxacin to turkeys (breed BUT 9; six animals per group) at a dose of 2 mg/kg of body weight (BW). At the same time, the serum concentrations of marbofloxacin were measured at different time intervals by a standardized high-performance liquid chromatography method, allowing the calculation of the most relevant kinetic parameters (PK parameters). The in vitro serum inhibitory activity of marbofloxacin against the selected E. coli strain, O78/K80, was 0.5 μg/ml in the blood serum of turkeys, and the ratio of the maximum concentration of the drug in serum to the serum inhibitory activity was 1.34. The lowest ratio of the measured serum concentration multiplied by the incubation period of 24 h to the serum inhibitory activity required for bacterial elimination was lower than the ratio of the area under the serum concentration-time curve (AUC) to the serum inhibitory activity. These first results suggested that the recommended dose of 2 mg/kg BW of marbofloxacin is sufficient to achieve a therapeutic effect in diseased animals. However, considering the risk of resistance induction, the applied dose should be equal to an AUC/MIC of >125, the generally recommended dose for all fluoroquinolones. According to the PK-PD results presented here, a dose of 3.0 to 12.0 mg/kg BW per day would be needed to meet this criterion. In conclusion, the results of the present study provide the rationale for an optimal dose regimen for marbofloxacin in turkeys and hence should form the basis for dose selection in forthcoming clinical trials