Post-market re-evaluation of medically important antimicrobials for veterinary use

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Approach to re-evaluation

We review veterinary drugs (including antimicrobials) before they go on the market and monitor them once they are on the market.

As science evolves, new information may become available about antimicrobials, including medically important antimicrobials (MIAs). MIAs are those important to human medicine. We will use an evidence-based approach to conduct re-evaluations on MIAs previously authorized for veterinary use.

The key objective of the re-evaluation is to determine whether the availability of MIAs or specific conditions of their use in veterinary medicine may contribute to anti-microbial resistance (AMR) in humans (that is, whether it increases the risk that MIAs become ineffective in treating infections in humans).

This approach to re-evaluation:

Our key activities include:

These initiatives are consistent with activities outlined in the Federal Action Plan on Antimicrobial Resistance and Use in Canada and Tackling Antimicrobial Resistance and Antimicrobial Use: A Pan-Canadian Framework for Action.


The evidence-based approach to the re-evaluation of antimicrobials on List A applies to:

We will consider using this approach for the post-market re-evaluation of other veterinary drugs, as appropriate, to protect the health of Canadians.

Evidence-based factors that may prompt a re-evaluation

The re-evaluation of an MIA or a class of MIAs may be initiated for a variety of reasons that relate to a change in an authorized product's risk-benefit profile. These factors may include:

Steps of the process

There are 5 key steps to our re-evaluation process. The extent and duration of a re-evaluation depends on:

We will work with impacted stakeholders on timelines and processes for particular re-evaluations.

Step 1 – Preliminary analysis

We analyze any information to determine whether the drug's established risk-benefit profile warrants a re-evaluation.
The purpose of this analysis is to:

Step 2 – Notice and preparation for re-evaluation

Before we undertake a re-evaluation, we will communicate with affected stakeholders.
We may seek additional information about the drug(s) from:

Step 3 – Science-based re-evaluation

The re-evaluation will focus on the:

We will assess the risks of AMR using various guidances, such as:

Step 4 – Re-evaluation outcomes

Our re-evaluation may result in using various risk management measures supported by authorities under the Food and Drugs Act and regulations. These measures may include:

Step 5 – Notification of re-evaluation results

When we complete the re-evaluation, we will:

Depending on the type of change(s) needed, we may share this information in different ways, such as by:

Contact us

For questions, contact us by email:

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