Baytril Injectable Solution (Canada)

Figure 1 - Serum Concentrations of Enrofloxacin Following a Single Oral or Intramuscular Dose at 2.5 mg/kg in Dogs and a Single Oral Dose at 2.5 mg/kg in Cats.

Breakpoint: Based on in-vitro susceptibility, pharmacokinetics and clinical response, the following breakpoints are recommended for canine isolates. These breakpoints have been approved by the National Committee for Clinical Laboratory Standards (NCCLS) and are published in NCCLS document M-31:

A report of ‘Susceptible’ indicates that the pathogen is likely to be inhibited by plasma levels generally attained with the lower end of the dose range (2.5 mg/kg BW twice daily or 5.0 mg/kg BW once daily). A report of ‘Flexible Label’ indicates that the pathogen is likely inhibited by plasma levels attained with adherence to the principles of FDA-approved Professional Flexible Labeling in dogs. With enrofloxacin, conditions due to ‘F’ bacteria can be treated successfully by administration of an intermediary dose within the lower (>5.0 mg/kg BW once daily) and upper (≤ 20 mg/kg BW once daily) limits of the approved flexible dose range.

Determination of the precise dosage is based upon a careful assessment of the interrelationships amongst host (immunocompetency, stress, site of infection, etc.), pathogen (virulence, MIC, emerging resistance, etc.) and chemotherapeutic (dose-dependent vs time-dependent efficacy, postantibiotic effects, toxicity etc.). A report of ‘Resistant’ indicates that the pathogen is unlikely to be inhibited by plasma levels attained with administration of the highest approved dose (20 mg/kg BW once daily) and alternative antimicrobial therapy should be selected.

Standardized procedures require the use of laboratory quality control organisms for both standardized disk diffusion assays and standardized dilution assays. The 5 µg enrofloxacin disk should give the following zone diameters and enrofloxacin powder should provide the following MIC values for reference strains. The indicated ranges for quality control organisms are NCCLS-approved.

Baytril Injectable Solution Indications

Dogs: Baytril (enrofloxacin) antibacterial injectable solution is indicated for the management of diseases in dogs associated with bacteria susceptible to enrofloxacin.

EFFICACY CONFIRMATION:

Dogs: Clinical efficacy was established in dermal infections (wounds and abscesses) associated with susceptible strains of Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, and Staphylococcus intermedius; respiratory infections (pneumonia, tonsillitis, rhinitis) associated with susceptible strains of Escherichia coli and Staphylococcus aureus; and urinary cystitis associated with susceptible strains of Escherichia coli, Proteus mirabilis, and Staphylococcus aureus.

Contraindications

Enrofloxacin is contraindicated in dogs known to be hypersensitive to quinolones.

Dogs: Based on the studies discussed under the section on Animal Toxicology, the use of enrofloxacin is contraindicated in small and medium breeds of dogs during the rapid growth phase (between 2 and 8 months of age). The safe use of enrofloxacin has not been established in large and giant breeds during the rapid growth phase. Large breeds may be in this phase for up to one year of age and the giant breeds for up to 18 months. In clinical field trials utilizing a daily oral dose of 5.0 mg/kg, there were no reports of lameness or joint problems in any breed. However, controlled studies with histological examination of the articular cartilage have not been conducted in the large or giant breeds.

Adverse Reactions

Post Approval Experience: The following adverse experiences, although rare, are based on voluntary post-approval adverse drug experience reporting. The categories of reactions are listed in decreasing order of frequency by body system.

Gastrointestinal: Anorexia, diarrhea, vomiting, elevated liver enzymes

Neurologic: ataxia, seizures

Behavioral: Depression, lethargy, nervousness

To report suspected adverse drug events or for technical assistance, contact Elanco Canada Limited at 1-800-265-5475.

ANIMAL TOXICOLOGY:

Adult dogs receiving enrofloxacin orally at a daily dosage rate 52 mg/kg for 13 weeks had only isolated incidences of vomition and inappetence. Adult dogs receiving the tablet formulation for 30 consecutive days at a daily treatment of 25 mg/kg did not exhibit significant clinical signs nor were there effects upon the clinical chemistry, hematological or histological parameters. Daily doses of 125 mg/kg for up to 11 days induced vomition, inappetence, depression, difficult locomotion and death while adult dogs receiving 50 mg/kg/day for 14 days had clinical signs of vomition and inappetence.

Adult dogs dosed intramuscularly for three treatments at 12.5 mg/kg followed by 57 oral treatments at 12.5 mg/kg, all at 12 hour intervals, did not exhibit either significant clinical signs or effects upon the clinical chemistry, hematological or histological parameters.

Oral treatment of 15 to 28 week old growing puppies with daily dosage rates of 25 mg/kg has induced abnormal carriage of the carpal joint and weakness in the hindquarters. Significant improvement of clinical signs is observed following drug withdrawal. Microscopic studies have identified lesions of the articular cartilage following 30 day treatments at either 5, 15 or 25 mg/kg in this age group. Clinical signs of difficult ambulation or associated cartilage lesions have not been observed in 29 to 34 week old puppies following daily treatments of 25 mg/kg for 30 consecutive days nor in 2 week old puppies with the same treatment schedule.

Tests indicated no effect on circulating microfilariae or adult heartworms (Dirofilaria immitis) when dogs were treated at a daily dosage rate of 15 mg/kg for 30 days. No effect on cholinesterase values was observed.

No adverse effects were observed on reproductive parameters when male dogs received 10 consecutive daily treatments of 15 mg/kg/day at 3 intervals (90, 45 and 14 days) prior to breeding or when female dogs received 10 consecutive daily treatments of 15 mg/kg/day at 4 intervals; between 30 and 0 days prior to breeding, early pregnancy (between 10th & 30th days), late pregnancy (between 40th & 60th days), and during lactation (the first 28 days).

DRUG INTERACTIONS:

Concomitant therapy with other drugs that are metabolized in the liver may reduce the clearance rates of the quinolone and the other drug.

Enrofloxacin has been administered to dogs at a daily dosage rate of 10 mg/kg concurrently with a wide variety of other health products including anthelmintics (praziquantel, febantel, sodium disophenol), insecticides (fenthion, pyrethrins), heartworm preventatives (diethylcarbamazine) and other antibiotics (ampicillin, gentamicin sulfate, penicillin, dihydrostreptomycin). No incompatibilities with other drugs are known at this time.

Baytril Injectable Solution Caution

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 associated with cartilage erosions in weight-bearing joints and other forms of arthropathy in immature animals of various species.

Warnings

To limit the potential development of antimicrobial resistance:

- fluoroquinolone drugs such as Baytril injectable solution 50 mg/mL should not be used indiscriminately.

- Baytril injectable solution 50 mg/mL should not be used in food producing animals.

Keep out of reach of children. Read package insert carefully for complete details.

Dosage and Administration

The optimum dose of Baytril (enrofloxacin) injectable solution has been established at 2.5 mg/kg (1.13 mg/lb) of body weight administered twice daily (every 12 hours). Baytril Injectable Solution (5%) may be used in dogs twice daily (every 12 hours) by intramuscular injection for up to three days (6 doses). Different injection sites must be used for each treatment. Twelve hours following the last injection dosing should continue with Baytril Tablets given once daily for 2-3 days beyond the cessation of clinical signs. Total treatment time with Baytril should not exceed 30 days. If no improvement is seen within five days, the diagnosis should be re-evaluated and a different course of therapy considered.

Storage

Protect from direct sunlight. Do not freeze and do not store above 40°C.

How Supplied

Baytril Injectable Solution 50 mg/mL

Vial Size

50 mL

References

¹ Hooper DC and Wolfson JS. Mechanisms of quinolone action and bacterial killing, in Quinolone Antimicrobial Agents. Washington DC, American Society for Microbiology, 2nd ed., 1993, 53-75.

² Gootz TD and Brighty KE. Fluoroquinolone antibacterials: sar. mechanism of action, resistance and clinical aspects. Medicinal Research Reviews 1996; 16(5): 433-486.

³ Drlica K and Zhoa X. DNA gyrase, topoisomerase IV and the 4-quinolones. Microbiology and Molecular Biology Reviews 1997; 61(3): 377-392.

⁴ Walker RD et al. Pharmacokinetic evaluation of enrofloxacin administered orally to healthy dogs. American Journal of Veterinary Research 1992; 53(12): 2315-2319.

Elanco Canada Limited, 1919 Minnesota Court, Suite 401, Mississauga, Ontario L5N 0C9

Baytril is sold by Elanco or its affiliates and is not a product of Bayer. The Product Name Baytril is owned by Bayer and used under license.

© 2022 Elanco or its affiliates.

11Apr2022

CPN: 1231204.1