Disposition of Enrofloxacin (Baytril®) into the Udder after Intravenous and Intra‐Arterial Injections into Dairy Cows

Abstract

Enrofloxacin (Bayad@) was injected into arteries supplying the udder of dairy cows. The idea was to avoid primary dismbution, metabolism and elimination and thus to deliver the drug to the target organ at hgha concentration. Enrofloxacin injected into the abdominal aorta or the external iliac artery resulted in high initial enrofloxacin retention by the udder and high milk concentrations.Injection of enrofloxacin into the abdominal aorta resulted in 2.2 times higher milk peak concentration of the drug than intravenous injection into the jugular vein. Injection of the drug into one of the two external iliac arteries dowed dmg concentrations of milk from the udder halves to be compared: when enrofloxacin w a s injected into the right external iliac artery, the peak milk enrofloxacin concentration from the right udder half was 4.8 times that of the left udder half. The bulk of enrofloxacin was absorbed from the milk compartment of the udder before the next regular milking 6.5 h later. By this time, the metabolite cipmfloxacin had accumulated in milk. Pharmacokinetic values for enrofloxacin and its metabolite ciprofloxacin are given separately for serum and milk whey following thrcc intravascular dosing mutes SANDHOLM, 1995). Drug concentrations in milk are low for many oral and parented antibacterial preparations. The drug can be targeted into a selected organ by injecting the dose into the artery supplying blood to that organ. Intra-arterial injections into cows have been a common practice in the former east block countries: Estonia, East Germany and Russia. The intra-arterial route of administration is rarely used in Western type veterinary practice. Although there have been a few reports on the clinical efficacy of antibacterials administered by the intra-arterial route in mastitis and metritis (LIPOV~SEV, 1964; COLOMBO land GUALLINI, 1967; MA= et al., 1987, sound pharmacokinetic studies are laclung. The us. CoplmBht acents S~D~~C 0931-184X/96/4306-0377$11.50/0

Population pharmacokinetics of enrofloxacin and its metabolite ciprofloxacin in chicken based on retrospective data, incorporating first-pass metabolism

“…, 1989). The metabolite (ciprofloxacin) formation in goats was 28.8%, which is similar to the results collected in cows (29.9%, Malbe et al. , 1996).…”

“…Enrofloxacin is partly biotransformed to ciprofloxacin by N-de-ethylation in the liver (Tyczkowska et al, 1989). The metabolite (ciprofloxacin) formation in goats was 28.8%, which is similar to the results collected in cows (29.9%, Malbe et al, 1996). Metabolism of enrofloxacin is variable in other animal species, and the extent of ciprofloxacin formation was 43% in dogs (Kung et al, 1993), 36% in Llams (Christensen et al, 1996), 20-25% in horses (Kaartinen et al, 1997) and <10% in ducks (Intorre et al, 1997).…”

Pharmacokinetic‐pharmacodynamic integration of enrofloxacin and its metabolite ciprofloxacin in buffalo calves

“…The pharmacokinetic behaviour of enrofloxacin after intravascular administration has been determined in cattle (Kaartinen et al 1995(Kaartinen et al , 1997Malbe et al 1996), goats (Elmas et al 2001;Elsheikh et al 2002;Rao et al 2002) and other ruminants (Gavrielli et al 1995;Christensen et al 1996) at the dose rate of 2.5-5 mg kg À1 body weight. Some studies on pharmacokinetics of enrofloxacin and ciprofloxacin have been performed in buffalo calves through intravenous (i.v.)…”

Effect of intramuscular diclofenac sodium on pharmacokinetics of intravenous enrofloxacin in calves

“…The total body clearance (Cl B ) obtained in the present study (467.51±41.36 ml/h/kg) was much lower than the lactating cows. [2] This difference might be due to both age and sex difference between the two studies. The Cl B value in case of combined administration (428.51±47.00 ml/h/kg) was decreased.…”

“…The elimination half-life (t ½ ) of enrofloxacin was found to be 1.38±0.05 h as compared to 1.01 h in dairy cows. [2] However, a slightly longer t ½ of 1.7 h in lactating cows of Ayrshire breed was reported. [3] The elimination half-life (t ½ ) in diclofenac sodium pretreated calves was 1.67±0.13 h, which Effect of intramuscular diclofenac sodium on pharmacokinetics Effect of intramuscular diclofenac sodium on pharmacokinetics Effect of intramuscular diclofenac sodium on pharmacokinetics Effect of intramuscular diclofenac sodium on pharmacokinetics Effect of intramuscular diclofenac sodium on pharmacokinetics of intravenous enrofloxacin in calves of intravenous enrofloxacin in calves of intravenous enrofloxacin in calves of intravenous enrofloxacin in calves of intravenous enrofloxacin in calves showed no significant difference with the t ½ value of single dose enrofloxacin.…”