For Your Information:
Approval of Baytril 100 for Treatment of Bovine Respiratory Disease

The Issue

Health Canada has recently approved for sale, the veterinary drug enrofloxacin, brand name Baytril 100, of the antibiotic class of fluoroquinolones. This drug has been approved for sale for therapeutic use only to treat bovine respiratory disease in beef cattle. Public health concerns have been raised internationally regarding the emergence of fluoroquinolone resistance in a large number of important human bacterial pathogens, which could lead to fewer effective antibiotics available to treat infections. That is why Health Canada undertook a thorough scientific evaluation of this product and its proposed use. The product was approved based on this evaluation.

Background

Baytril 100 is a veterinary drug (a specific dose of Baytril - 100 mg/mL injectable solution) that will provide veterinarians with an alternative course of treatment for bovine respiratory disease when other antibiotics are not effective. Before the approval of Baytril 100, no fluoroquinolones were approved in Canada for use in food-producing animals. However, Baytril has been approved for sale in Canada for use in dogs and cats for many years.

Before Baytril 100 was approved for use in beef cattle, a comprehensive scientific evaluation was performed of its chemistry and manufacturing, efficacy and safety in the intended species, human safety including toxicity, residues and microbiological safety. Antimicrobial resistance considerations were a key element of the microbiological safety review.

Baytril 100 is intended to be used for treating bovine respiratory disease and, due to concerns for antimicrobial resistance, its approved uses have been restricted for relapse cases after initial treatments have failed. As such, it is anticipated that the use of Baytril 100 in beef cattle will be limited.

Context

1/ Antimicrobial Resistance and Human Health

Over a period of two years, an exhaustive assessment was conducted by Health Canada's scientists. International studies on antimicrobial resistance issues related to this drug product were considered as part of this assessment. Analysis of available scientific studies, including research and surveillance data, indicates that there is no apparent risk of antimicrobial resistance when Baytril 100 is used prudently in beef cattle for therapeutic purposes. Health Canada's evaluation concluded that the use of Baytril 100 in beef cattle in Canada, as directed on the label, will not pose undue human health risk associated with antimicrobial resistance in foodborne bacterial pathogens such as Escherichia coli, Campylobacter spp. and Salmonella spp.

An environmental impact assessment of this application was completed, and the data demonstrated that there is very low risk of adverse environmental contamination when this drug is used according to the directions on the label.

2/ International Trade

Baytril is approved for use in beef cattle in 25 countries, including the United States (US) and member states of the European Union (EU). It is also approved for use in beef cattle in New Zealand and Finland under stringent conditions similar to Canada. Over the last few years, the US Food and Drug Administration (FDA) Center for Veterinary Medicine (CVM) has held public hearings on the safety of Baytril (enrofloxacin) 3.23 percent concentrate antimicrobial solution for use in poultry following the CVM's proposal to withdraw approval for the use of this product in drinking water for poultry. Public health concerns raised in the US have focused on the use of Baytril in poultry production and not on its use in beef cattle.

In March 2004, an initial decision to withdraw Baytril 3.23 percent for use in poultry was issued by an FDA Administrative Law Judge. In the absence of the timely filing of exceptions; this initial decision will become the final decision of the Commissioner. In the meantime, Baytril 3.23 percent remains on the US market pending resolution of this case.

Baytril 3.23 percent is not approved for use in food-producing animals in Canada and the importation of this drug product into Canada for such use contravenes the Food and Drugs Act and Regulations.

Responsibilities

1/ Government of Canada

The federal government ensures that all approved drugs have been reviewed and determined to be safe and efficacious for the proposed use(s). Since post-market surveillance is important in monitoring the safety of any drug once in use, especially in the case of antimicrobial drugs with regards to antimicrobial resistance, Health Canada, through the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS), will monitor and track any increases in antimicrobial resistance levels in E. Coli and Salmonella spp. in beef cattle. CIPARS will collect representative bacterial samples from the abattoir-level, retail beef-level and from human tissue isolates. VDD will also track and assess any Adverse Drug Reaction (ADR) reports submitted by veterinarians and the manufacturer.

The Canadian Food Inspection Agency (CFIA) has a program in place to monitor Canada's food supply and has analytical methods in place for detecting violative residues of this class of drugs in edible tissues derived from animals.

Should there be an apparent risk of increasing resistance to this drug as a result of usage in beef cattle, Health Canada will ensure that appropriate interventions are taken which could, if necessary, lead to withdrawal of the product from the market.

2/ Producers and Veterinarians

Health Canada has required the manufacturer to include explicit directions including WARNING statements on the label. The product must not be used in an extra-label manner in any species, including other bovines (veal calves and dairy cattle) and the mandatory withdrawal period must be strictly observed. Baytril 100 is available by prescription only, through a veterinarian, and should be used only for treating relapse cases of bovine respiratory disease after initial treatments have failed. When used in accordance with the directions on the label, food derived from treated animals is considered safe for human consumption.

How can I keep up-to-date on this issue?

You can get up-to-date information on Baytril and other veterinary drug health issues by visiting our Web site:
http://www.hc-sc.gc.ca/dhp-mps/index_e.html

Health Canada contact information:

Veterinary Drugs Directorate
Health Products and Food Branch
Health Canada
Holland Cross Complex, Ground Floor
14 - 11 Holland Avenue
Ottawa, Ontario. K1A 0K9
Address Locator - 3000A

General Information Number: (613) 954-5687
Fax: (613) 957-3861
E-mail: vetdrugs-medsvet@hc-sc.gc.ca