Pharmacovigilance:

Monitoring Suspected Adverse Reactions to Animal Medicines

Briefing Document No. 17

Introduction

Thankfully, harmful, unexpected side-effects to animal medicines are extremely uncommon. Before any animal medicine is allowed onto the UK market it has, by law, to satisfy very strict criteria on its quality, its effectiveness and its safety. However, once an animal medicine is in use, it is vital to know if any animals or people suffer unexpected problems following use or exposure to the product under field conditions.

Very occasionally animals may show some small mild reaction to a medicine – just as you may feel drowsy after certain common medications. But, if your animal is unwell after treatment with an animal medicine or if you are at all worried, contact your vet. This is just common-sense, whether or not your animal has received medication, and it is more than likely that the illness is totally unrelated to the medicine.

Suspected Adverse Reaction Surveillance Scheme

The Veterinary Medicines Directorate (VMD), which administers the licensing system, runs a scheme to monitor reports of any reactions in animals and people following the use of animal medicines, called the Suspected Adverse Reaction Surveillance Scheme.

The purpose of the scheme is to monitor trends in reported suspected reactions. Reports received by the VMD are prioritised in terms of severity and likely causality (i.e. to see whether the problem is likely to be linked to the medicine). The scheme also analyses whether there have been any other reports about the same product or others like it, whether any further information is required and whether any follow-up is required.

The legal background

Chapter VIa of Veterinary Medicinal Products Directive 81/851/EEC, headed Pharmacovigilance, imposes certain duties on holders of marketing authorisations. The European Committee for Veterinary Medicinal Products adopted a Note for Guidance entitled Pharmacovigilance of Veterinary Medicinal Products which came into operation on 1 January 1998.

This European guideline sets out the recommended framework for pharmacovigilance which places specific duties on conditions attached to individual product authorisations. Duties are also placed on member states’ competent authorities (the VMD in the UK).

Company responsibilities

Article 42c of Directive 81/851/EEC requires the holder of each marketing authorisation to “have permanently and continuously at his disposal an appropriately qualified person responsible for pharmacovigilance”.

The appropriately qualified person is responsible for setting up and operating a system which ensures that all information about any suspected adverse reactions reported to the company is collected and collated at a single point. Records of suspected adverse reactions must by law be kept for at least 5 years.

Periodic Safety Update reports should be sent in on the request of the Suspected Adverse Reaction Surveillance Scheme or as required by the VMD. Generally, however, they are submitted six-monthly for the first 2 years after product authorisation, annually for the subsequent 3 years, and thereafter every 5 years.

This report lists all the suspected adverse reactions reported to the company since the last Periodic Safety Update report. This is set into context by looking at the incidence of reactions, taking account of the number of doses sold. Each Periodic Safety Update report should contain a concise assessment of the evaluation of the current safety of the product.

Reporting suspected adverse reactions

If an adverse reaction to an animal medicine is suspected, it should be reported to the scheme and/or the company involved. Your vet or doctor will normally do this: they are actively encouraged to do so by both the VMD and NOAH, but the VMD welcomes anyone reporting such adverse reactions they have experienced or observed. Yellow forms for doing this are available from the VMD.

Often, vets will contact the manufacturer directly to report a suspected adverse reaction. Companies are then under a legal obligation to report these to the VMD – half of all reports come directly from companies.

Only by professionals and owners taking the trouble to report any problems can the VMD and companies get an idea of any action that may need to be taken. This could ultimately mean withdrawing the product or a specific batch from the market, but more usually it will result in more advice being given to users of the medicine as to how to use it safely, or on possible side-effects.

NOAH encourages active reporting of suspected adverse reactions, but is pleased that there are so few. This shows that the authorisation system for animal medicines is doing its job and protecting animals and the public from potential danger.

Definitions

Adverse reaction: a reaction in an animal which is harmful and unintended and which occurs at doses normally used in animals for the prophylaxis, diagnosis or treatment of disease or the modification of physiological function (Article 42b of Directive 81/851).

Human Adverse Reaction: an incident where a person reports adverse effects following exposure to a veterinary medicinal product.

Periodic Safety Update Report: see above, under 'Company responsibilities'.

Suspected adverse reaction (SAR): any report indicating that there has or may have been an adverse reaction to a product. The Suspected Adverse Reaction Surveillance Scheme treats all reports of adverse reactions as suspected until shown to be otherwise.

FURTHER INFORMATION

· Further information on the Suspected Adverse Reaction Surveillance Scheme and forms for reporting suspected adverse reactions are available from the VMD, telephone 01932 336911.

· See also NOAH Briefing Document 19 on the licensing system for animal medicines.

September 1999