Baytril 100 (Canada)
This page contains information on Baytril 100 for veterinary use.The information provided typically includes the following:
- Baytril 100 Indications
- Warnings and cautions for Baytril 100
- Direction and dosage information for Baytril 100
Baytril 100
This treatment applies to the following species:
Manufacturer: Bayer
(enrofloxacin)
100 Mg/ml Sterile
Antimicrobial Injectable Solution
1405984
DIN 02249243
VETERINARY USE ONLY
Baytril 100 Indications
For the treatment of bovine respiratory disease (BRD) associated with Mannheimia (Pasteurella) haemolytica and Pasteurella multocida.Product Description
Baytril 100 is a sterile, ready-to-use injectable antimicrobial solution that contains enrofloxacin, a fluoroquinolone antimicrobial agent.Therapeutic treatment with Baytril 100 injectable solution may be administered as a single-dose or as a multiple-day therapy.
Each milliliter of Baytril 100 injectable solution contains 100 mg of enrofloxacin. Excipients are L-arginine base 200 mg, n-butyl alcohol 30 mg, benzyl alcohol (as a preservative) 20 mg, and water for injection, q.s.
Chemical Nomenclature And Structure
1-cyclopropyl-7-(4-ethyl-1-piperazinyl)-6-fluoro-1, 4-dihydro-4-oxo-3-quinolinecarboxylic acid.Microbiology
Enrofloxacin is bactericidal and exerts its antibacterial effect by inhibiting bacterial DNA gyrase (a type II topoisomerase) thereby preventing DNA supercoiling and replication, which leads to cell death1. Enrofloxacin has demonstrated in vivo activity against Mannheimia (Pasteurella) haemolytica and Pasteurella multocida, the major pathogenic bacteria associated with bovine respiratory disease. Enrofloxacin is active in vitro against gram-negative and gram-positive bacteria. In vitro activity against Mycoplasma spp. has also been detected.The Minimum Inhibitory Concentrations (MIC's) of enrofloxacin were determined2 for isolates obtained from natural infections in cattle during 1994 and 1995 (See Table 1).
Table 1 - Mic Values (µg/ml) Of Enrofloxacin Against Bacteria And Mycoplasma Isolated From Natural Infections.
Isolate |
No. Isolates |
Mic50 ** |
Mic90** |
|
Actinomyces pyogenes* |
105 |
1 |
1 |
|
Escherichia coli* |
100 |
0.03 |
0.06 |
|
Haemophilus somnus* |
104 |
0.015 |
0.03 |
|
Mycoplasma spp* |
124 |
0.25 |
0.5 |
|
Mannheimia (Pasteurella) haemolytica |
121 |
0.06 |
0.06 |
|
Pasteurella multocida |
108 |
0.015 |
0.03 |
* The clinical significance of these in vitro data has not been demonstrated.
** The MIC for 50% and 90% of the isolates.
Interpretive criteria (zone diameters and MIC breakpoints) have been established as an in vitro aid to estimate in vivo efficacy of Baytril 100 against pathogens listed on the label.
(NCCLS document M31-A2 (ISBN 1-56238-461-9) 2002)
The approved interpretive criteria are listed below:
Interpretation |
Zone Diameters (mm) |
Mic Breakpoints (µg/ml) |
|
Susceptible |
≥ 21 |
≤ 0.25 |
|
Intermediate |
17 - 20 |
0.5 - 1.0 |
|
Resistant |
≤ 16 |
≥ 2.0 |
Pharmacokinetics
Pharmacokinetic studies were conducted in healthy beef calves. A HPLC assay was used to determine the concentrations of enrofloxacin and its metabolites. Baytril 100 is rapidly and completely absorbed following subcutaneous administration. Plasma concentrations increase proportionally with dose indicating linear pharmacokinetics. Enrofloxacin is primarily metabolized by the liver. It is de-ethylated to the main metabolite ciprofloxacin whose antimicrobial activity is additive with enrofloxacin. Also, glucuronidation occurs facilitating biliary secretion. In the gastrointestinal tract, parent compounds may be hydrolyzed from glucuronide metabolites and reabsorbed. About 60% and 40% of an enrofloxacin dose is excreted via feces and urine, respectively.Plasma pharmacokinetic parameters estimated after single subcutaneous injection of Baytril 100 are given in Table 2.
Table 2. Pharmacokinetic Parameters (means) Estimated After Single Subcutaneous Administration Of Baytril 100 To Beef Calves.
|
Dose |
n |
Analyte |
Cmax |
tmax |
t1/2 |
AUC0-48 |
|
2.5 |
8 |
Enrofloxacin |
0.37 |
3.4 |
5.4 |
3.06 |
|
5.0 |
7 |
Enrofloxacin |
0.69 |
3.3 |
5.9 |
6.95 |
|
7.5 |
8 |
Enrofloxacin |
0.83 |
5.8 |
6.4 |
8.66 |
|
Ciprofloxacin |
0.32 |
6.5 |
-a |
- |
anot estimated; n, number of calves; Cmax, maximum serum concentration; tmax, time to achieve Cmax; t1/2, terminal elimination half-life; AUC0-48, area under serum concentration-time curve from 0 to 48 h after application.
A concentration-time curve showing mean enrofloxacin and ciprofloxacin levels after single subcutaneous administration of enrofloxacin at 7.5 mg/kg is presented in Figure 1.
Figure 1. Mean Enrofloxacin And Ciprofloxacin Plasma Concentrations Following A Single Subcutaneous Dose Of Baytril 100 At 7.5 Mg/kg In Beef Calves (n=8).
The calculated volume of distribution at steady state (Vss) of 1.46 L/kg after a single intravenous injection of 7.5 mg/kg indicates extensive tissue penetration. This is confirmed by the finding that concentrations in lung tissues are about 2 times higher than corresponding plasma levels (Table 3).
Table 3. Mean Enrofloxacin And Ciprofloxacin Concentrations In Lung Tissue And Plasma At Various Time Points Following A Single Subcutaneous Dose Of Baytril 100 At 2.5 Mg/kg In Beef Calves (n=6).
Sample |
Analyte |
Concentration (µg/ml) Or (µg/g) At Sampling Time (h) |
|||
2 |
4 |
8 |
24 |
||
|
Lung |
Enrofloxacin |
0.39 |
0.47 |
0.44 |
0.04 |
|
Ciprofloxacin |
0.13 |
0.25 |
0.31 |
0.05 |
|
|
Plasma |
Enrofloxacin |
0.21 |
0.30 |
0.29 |
0.01 |
|
Ciprofloxacin |
0.05 |
0.12 |
0.13 |
0.02 |
|
Efficacy
A total of 845 feedlot calves with naturally-occurring bovine respiratory disease (BRD) were treated with Baytril 100 in eight field trials located in five cattle-feeding states of the U.S.A. Response to treatment was compared to non-treated controls. Single-dose and multiple-day therapy regimens were evaluated. BRD and mortality were significantly reduced in enrofloxacin-treated calves. No systemic adverse reactions were reported in treated animals.Toxicology
The oral LD50 for laboratory rats was greater than 5000 mg/kg of body weight. Ninety-day feeding studies in dogs and rats revealed no observable effects at treatment rates of 3 and 40 mg/kg respectively. Chronic studies in rats and mice revealed no observable adverse effects at 5.3 mg/kg and 323 mg/kg respectively. There was no evidence of carcinogenic effect in laboratory animal models. A two-generation rat reproduction study revealed no effect with 9.9 mg/kg treatments. No teratogenic effects were observed in rabbits at doses of 25 mg/kg or in rats at 50 mg/kg.Animal Safety
Safety studies were conducted in feeder calves using single doses of 5, 15, and 25 mg/kg for 15 consecutive days and 50 mg/kg for 5 consecutive days. No clinical signs of toxicology were observed when a dose of 5 mg/kg was administered for 15 days. Clinical signs of depression, incoordination and muscle fasciculation were observed in calves when doses of 15 or 25 mg/kg were administered for 10 to 15 days. Clinical signs of depression, inappetance and incoordination were observed when a dose of 50 mg/kg had been administered for 3 days. No drug-related abnormalities in clinical pathology parameters were identified. No articular cartilage lesions were observed after examination of stifle joints from animals administered 25 mg/kg for 15 days.A safety study was conducted in 23 day-old calves using doses of 5, 15 and 25 mg/kg for 15 consecutive days. No clinical signs of toxicity or changes in clinical pathology parameters were observed. No articular cartilage lesions were observed in the stifle joints at any dose level at 2 days and 9 days following 15 days of drug administration.
An injection site study conducted in feeder calves demonstrated that the formulation may induce reaction in the subcutaneous tissue and underlying muscle. No painful responses to administration were observed.
Baytril 100 Caution
The safety of enrofloxacin in breeding cattle and pregnant or lactating cows has not been established.Subcutaneous injection can cause local tissue reaction that may result in trim loss at slaughter. Administered dose volume should not exceed 10 mL per injection site.
Quinolone-class drugs should be used with caution in animals with known or suspected Central Nervous System (CNS) disorders. In such animals, quinolones have, in rare instances, been associated with CNS stimulation which may lead to convulsive seizures.
Quinolone-class drugs have been shown to produce erosions of cartilage of weight-bearing joints and other signs of arthropathy in immature animals of various species. No articular cartilage lesions were observed in the stifle joints of 23-day-old calves at 2 days and 9 days following treatment with enrofloxacin at doses up to 25 mg/kg for 15 consecutive days.
Baytril 100 Dosage And Administration
Baytril 100 injectable solution provides flexible dosages and durations of therapy. Baytril 100 may be administered as a single dose for one day or for multiple days of therapy. Selection of the appropriate dose and duration of therapy should be based on an assessment of the severity of disease, pathogen susceptibility and clinical response. Administered dose volume should not exceed 10 mL per injection site.Single Dose Therapy
Administer once, a subcutaneous dose of 7.5 - 12.5 mg/kg of body weight (7.5 - 12.5 mL/100 kg).Multiple Dose Therapy
Administer daily (every 24 hours) for 3 days, a subcutaneous dose of 2.5 - 5.0 mg/kg of body weight (2.5 - 5.0 mL/100 kg). For animals that are clinically improved but still exhibit some signs of disease, additional treatments may be given on days four and five.Table 4 - Baytril 100 Dose And Treatment Schedule
Cattle Weight(kg) |
Single Dose Therapy7.5 - 12.5 Mg/kg Dose Size (ml) |
Multiple-day Therapy2.5 - 5.0 Mg/kg Dose Size (ml) |
|
50 |
3.75 - 6.25 |
1.25 - 2.5 |
|
100 |
7.5 - 12.5 |
2.5 - 5.0 |
|
150 |
11.25 - 18.75 |
3.75 - 7.5 |
|
200 |
15.0 - 25.0 |
5.0 - 10.0 |
|
250 |
18.75 - 31.25 |
6.25 - 12.5 |
|
300 |
22.5 - 37.5 |
7.5 - 15.0 |
|
350 |
26.25 - 43.75 |
8.75 - 17.5 |
|
400 |
30.00 - 50.00 |
10.0 - 20.0 |
|
450 |
33.75 - 56.25 |
11.25 - 22.5 |
|
500 |
37.5 - 62.5 |
12.5 - 25.0 |
Note: Subcutaneous injection can cause a transient local tissue reaction that may result in trim loss of edible tissue at slaughter.
Warning
Treated cattle must not be slaughtered for use in food for at least 36 days after the latest treatment with this drug. Do not use in dairy cattle. Do not use in veal calves. The withdrawal period has not been established in preruminating calves. Do not use in an extra-label manner in cattle or in any other species.To limit the potential development of antimicrobial resistance: fluoroquinolone drugs such as Baytril 100, should not be used indiscriminately.
Baytril 100 should not be used as an arrival treatment for feedlot cattle.
Baytril 100 should only be used for treating individual relapse cases of bovine respiratory disease after initial treatments have failed.
the choice of Baytril 100 as the most appropriate treatment should be confirmed by clinical experience supported, where possible, by pathogen culture and susceptibility testing.
Keep Out Of Reach Of Children
Storage
Do not store below 4°C or above 30°C. Protect from direct sunlight.References
1. Hooper, D.C., Wolfson, J.S., Quinolone Antimicrobial Agents, 2nd ed., 59-75, 1993.
2. National Committee for Clinical Laboratory Standards, Performance Standards for Antimicrobial Disk and Dilution Susceptibility Tests for Bacteria Isolated from Animals; Proposed Standard, Document M31-P, 1994.
U.S. Patent No. 4,670,444
® Baytril, Bayer and Bayer Cross are registered trademarks of Bayer AG, used under license.
Bayer HealthCare, Animal Health Division, Bayer Inc., Toronto, Ontario M6W 1G6
|
250 mL |
AHLB100D604 |
Nac No.
12230332Animal Health Division, Bayer Inc.
77 BELFIELD ROAD, TORONTO, ON, M9W 1G6
| Telephone: | 416-248-0771 or 800-268-1331 | |
| Toll-Free: | 800-62-BAYER | |
| Order Desk: | 800-387-9179 | |
| Order Desk Fax: | 800-361-3306 | |
| Fax: | 416-240-4918 | |
| Website: | www.animalhealth.bayer.ca |
 |
Every effort has been made to ensure the accuracy of the Baytril 100 information published above. However, it remains the responsibility of the readers to familiarize themselves with the product information contained on the Canadian product label or package insert. |
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