Extra-Label Drug Use (ELDU) is often referred to as "off-label use" in human medicine. In animals, ELDU refers to the actual use or intended use of any drug, whether it is a prescription drug or over-the-counter drug, in an animal in a manner that is not in accordance with the approved label or the package insert of the drug licensed by Health Canada. This definition includes the use of all unlicensed drugs, including unapproved bulk active pharmaceutical ingredients (APIs) and compounded drugs.
The labels for drug products include package labels such as package inserts, prescribing information, fact sheets, or other materials containing drug product- specific information, whether included in packaging or supplied to the end user at the time of purchase or after purchase.
On each drug product approved by Health Canada, whether human or veterinary, there is a Drug Identification Number (DIN) specific to that drug product.
The Drug Identification Number (DIN) is the number located on the label of prescription and over-the-counter drug products that have been evaluated by Health Canada and approved for sale in Canada. Once a drug has been approved, Health Canada issues a DIN, which permits the manufacturer to market the drug in Canada. A DIN lets the user know that the product has undergone and passed a review of its safety, efficacy and quality. It also shows that Health Canada has verified and approved the formulation, labelling and instructions for use of the approved drug product. Any drug product sold in Canada without a DIN is not in compliance with the Canadian law. The DIN provides a tool to help in the follow-up of products on the market, recall of products, inspections, and quality monitoring.
The DIN is an eight-digit numerical code assigned to each drug product and it is preceded by three capital letters, DIN. An approved drug product should have a DIN clearly displayed on the drug label.
The drug review process at Health Canada ensures that new drug products undergo rigorous scientific scrutiny and fully satisfy all requirements and criteria that are prescribed by the Food and Drug Regulations. Drug sponsors must meet these criteria in order to have their drug products approved for sale in Canada. Health Canada's authorization is granted upon satisfactory review of the safety, efficacy and quality of the drug products. Throughout the process, the safety and well-being of Canadians, their animals and the environment are of paramount concern.
When an individual makes a decision to administer a drug product on animal(s) in an extra-label manner, there are potential public health and food safety risks involved. Some of the implications of ELDU practice are as follows:
The Food and Drug Regulations specify a "Maximum Residue Limit (MRL)" or the amount of residue that could remain in the tissue or food product derived from a food producing animal that has been treated with a veterinary drug. The presence of trace amount of administered drug product, in animal-derived food products, that is beyond the established MRL (expressed in p.p.m) for the specific veterinary drug constitutes violative drug residues. MRLs are established only after the Health Canada's Veterinary Drugs Directorate has conducted extensive reviews of data submitted by manufacturers and determined that foods containing these veterinary drug residues up to the recommended levels are safe for human consumption. In cases where MRLs have not been established for the specific veterinary drugs, no detectable residues are permitted in animal-derived food products. Health Canada is actively working to have MRLs established for drug products that could be used in food-producing animals.
Evidence has shown that the practice of ELDU in Canada is not restricted to veterinarians. It is being practiced by a variety of people, including laypersons, feed mill operators, feedlot managers, wildlife officers, animal breeders, pet owners, pet shop owners and employees, and by intermediate professionals such as pharmacists and animal health technicians.
In Canada, the federal legislative authority for regulating the approval, sale and labelling of veterinary drugs is the responsibility of Health Canada. The Canadian Food Inspection Agency (CFIA) is responsible for enforcing the health and safety standards set by Health Canada. In the case of veterinary drugs, this is done through the residue monitoring program and, specifically, sampling and testing of food products of animal origin. The authority and accountability for the prescribing and use of veterinary drugs falls under provincial and territorial jurisdiction.
In recent years, increased attention has been focussed on ELDU in Canada partly as a result of concerns about the potential for ELDU abuse and/or misuse and the potential public health risks relating to the uncontrolled practice of ELDU in Canada. These concerns were also highlighted in the European Commission's (EC) 2007 audit report on the evaluation of the Canadian control of residues and contaminants in live animals and animal products, including the control of veterinary medicinal products. In order to address these concerns, a comprehensive action plan aimed at ensuring a national approach for the effective control of extra label use of veterinary drugs was deemed imperative. Health Canada's policy on ELDU will is construed to set a national standard for the effective control of ELDU in food-producing animals in Canada. Health Canada's primary goal is to maintain the safety of our food system.
In Canada, the use of drugs is a complex multi-jurisdictional issue involving the federal government and the various provinces and territories. Health Canada regulates the sale but not the use of drugs. The use of veterinary drugs per se comes under the "practice of veterinary medicine", a provincial jurisdiction. Currently, there are no federal Canadian regulations defining the requirements for the practice of ELDU, with the exception of medicated feeds, whose requirements are described in the ELDU policy and could also be found in the Food and Drug regulations C.08.012.
The use of drugs in food-producing animals can lead to potentially harmful residues in the edible products harvested from these animals. Since human food safety is an important aspect that is considered in the review of veterinary drugs that would be administered to food-producing animals, Health Canada considers it a priority to focus only on food-producing animals.
As defined in the Meat Regulations of Canada, "food animal" includes animals in the class of mammals or birds that are slaughtered and processed as meat products for human consumption and for which inspection systems have been established. In the context of the ELDU policy, food-producing animals refer to animals that could be slaughtered and processed as meat products for human consumption in Canada.
Consistent with international direction, Health Canada takes the following view on the practice of ELDU:
ELDU in food producing animals by persons other than licensed veterinarians is not recommended except when such use is conducted under the supervision of a veterinarian within the context of a "valid Veterinarian-Client-Patient Relationship "(VCPR).
This approach is universal and should be applied for the benefit of public health and animal safety.
Health Canada considers a "valid VCPR" to exist when the following conditions apply:
These four elements need to be present in order to establish a "valid VCPR".
The entire responsibility is assumed by the individual who is practicing ELDU.
The antimicrobials in Category I are considered of "very high importance" or "critically important" in human medicine as they are essential for the treatment of serious bacterial infections and there are limited or no availability of alternative antimicrobials in case of resistance to these antimicrobials. Health Canada is recommending against their use in an ELDU manner because it is essential that we protect the efficacy of these drugs by using them prudently and judiciously, as indicated on the approved label.
The current list of Category I antimicrobials includes the following examples:
Banned substances should never be used in food-producing animals because residues of these substances in food could cause fatal diseases in humans, if ingested.
The list of substances prohibited for sale for administration to food-producing animals in Canada is as follows:
C.01.610.1 (Banned Substances):
There are multiple requirements by the Food and Drug Regulations (C.08.012). However here are the most important that you should always consider and respect when you are preparing a medicated feeds different than what is prescribed in the MIB.
Extra label use of a drug may take many forms. Below is a list of examples of ELDU which all require a valid VCPR.