The Veterinary Drugs Directorate (VDD) at Health Canada will use the CVMA annual convention in Halifax as a forum to discuss an important national-based survey on the practice of extra-label use for animals in Canada. It is intended that this survey of a broad cross-section of end users of drugs for use in animals be conducted this fall. Four broad categories will be surveyed: food-producing-animal veterinary practitioners, farmers and animal producers, feedmill operators, non-food- producing-animal veterinary practitioners.
What is extra-label use?
Extra-label use (ELU) is defined as the use of a drug product in a manner that is not consistent with what is indicated on the label, package insert, or product monograph of any drug product approved by Health Canada. Reference is also often made to off-label use, where an unapproved drug is used in a manner that has never been approved by a regulatory authority. For purposes of this contract, ELU will be defined as applying to both situations.
Extra-label use can take many forms. Both prescription and nonprescription drug products, for example, over-the-counter products may be used in an extra-label manner. The drug may be used in a different manner from that indicated on the label, such as at an increased dosage, a greater or lesser frequency, different indications, longer or shorter duration of treatment, or administration in different ways (oral versus injectable). It may also be used for different animal species or age groups, in a different form (a tablet may be crushed into powder and mixed into a gel), or in combination with other drugs. It may be a humn drug administered to an animal.
Extra-label use can be practised by a variety of people, ranging from veterinarians to laypersons; intermediate health professionals such as pharmacists and health technicians; feedmill operators; feedlot managers; wildlife officers; animal breeders; pet owners; pet shops, etc.
Why is extra-label use of concern?
Extra-label use is a public health and food safety issue of interest to different stakeholders on the Canadian scene, as well as Canadian international trade partners. Some of the issues are as follows:
Drug residues may be present in food products derived from ELU-treated animals consumed by humans or in feed by-products fed to other animals;
Adverse reactions may arise in treated animals, since these products have not been tested appropriately for these new conditions of use;
Drugs used in this manner may have a reduced or uncertain efficacy for the conditions being treated;
There may be ethical and liability considerations for veterinarians prescribing extra-label drugs that do not have proven safety or efficacy characteristics;
ELU has the potential to initiate trade restrictions;
Canadian provincial/territorial regulatory authorities do not apply consistent or equivalent rules from province to province to control or monitor ELU and its associated food safety and public health outcomes; and
ELU may be a potential contributing factor in the development of antimicrobial resistance (AMR).
What is the objective of the study?
The objective is to gather up-to-date and comprehensive information and understanding of the nature and scope, as well as the impacts, of the ELU of drugs in animals in Canada. As well, the drugs most commonly prescribed by veterinarians or used by producers or farmers in an extra-label manner will be identified. The issue of AMR will also be examined. Trends, practices, and interventions that might be used eventually to mitigate risks associated with ELU, as well as provide the basis for educational and awareness initiatives, will be addressed.
The results will be used to benchmark this practice especially for food-producing animals (cattle, poultry, swine, sheep). This will assist the VDD to better define the context, contributing factors, and implications on public health, food safety, and animal health. The results of this survey will be also be used as a tool for policy development in this area.
When will the results be made public?
It is expected that results of the survey will be communicated by way of a report to stakeholders in the winter of 2003.
(by Diane Kirkpatrick, Director General, Veterinary Drugs Directorate, Health Canada)
