What are Adverse Events?

Adverse Events (AEs) are defined as ‘any untoward medical occurrence that may present during treatment with a pharmaceutical product regardless of perceived causation’. AEs may include effects on the patient, humans handling the products or patient, or the environment. Lack of efficacy events are also AEs.

Who manages Adverse Event reports and who can report them?

The Veterinary Medicines Directorate (VMD) and Marketing Authorization Holders (MAHs) work together to collate information about, identify and mitigate risks associated with veterinary pharmaceuticals. These processes rely on spontaneous reporting of AEs. Anyone can report an AE, including veterinary professionals, owners and other interested parties. Under the RCVS Code of Professional Conduct veterinary surgeons and veterinary nurses are required to report adverse events.

Why is reporting Adverse Events important?

Prior to receiving a marketing authorization (licence), veterinary medicines undergo a significant amount of testing and evaluation. During this phase many of the more common AEs associated with a medicine will be identified. However, pre-marketing testing cannot hope to identify all possible AEs that will occur once a product is in widespread clinical use in a diverse population of animals or for ‘off-label’ use. In addition, products without an authorization do not undergo such testing.

Not all AEs are true adverse drug reactions (ADRs). AE reports are collated and analysed to identify statistically associated drug–event combinations. Reported cases are also reviewed to determine whether a causal relationship is likely. As the identification of true ADRs relies on statistical analysis, higher reporting rates allow the VMD to identify and mitigate any potential harm caused by a particular drug more quickly. A further benefit is that reporting both known and unknown events makes ADRs more prevalent in particular species, breeds, diseases and combinations of drugs more likely to be identified.

How to report an Adverse Event?

Adverse events can be reported to the VMD or the MAH (for authorized products); these organizations share AE information so there is no need to report to both. Reports to the VMD can be made via a dedicated webpage (https://www.gov.uk/report-veterinary-medicine-problem). A paper form can be downloaded if required. Most practices participating in the Small Animal Veterinary Surveillance Network (SAVSNET) can also report via their practice management systems.

The VMD pharmacovigilance team can be contacted on email at [email protected] or by telephone on 01932 336911.