ADVERSE EFFECTS OF MEDICATIONS
KEY POINTS
· Adverse effects may occur in human and veterinary medicine.
· Products commercially available have passed extensive testing and safety regulations.
· The Veterinary Medicines Directorate (VMD) monitors adverse effects with their designated pharmacovigilance team.
· Anyone can report an adverse event including vets, doctors, pharmacists, farmers and members of the public.
· The VMD encourage anyone involved in prescribing and using animal medicines to report suspected adverse events to the VMD or the animal medicine company.
PHARMACOVIGILANCE
Veterinary adverse events are monitored and evaluated in order to improve the safety of veterinary medicines. If a medicine is suspected to have failed to work (lack of efficacy) it is reported and monitored. This is called pharmacovigilance. Pharmacovigilance also covers residues of medicines that may reach the food chain, where withdrawal times are established. This is outside of the scope of this article.
An Adverse Event (AE) is any observation in animals, humans or the environment, whether or not considered to be product-related, that is unfavourable and unintended and that occurs after any use of a veterinary medicine.
All authorised veterinary medicines that are commercially available have gone through extensive safety, efficacy and quality assessments. Adverse events may occur, as with any medication, but the benefits to use a given medication for a specific process outweighs any known potential risks. This is a risk assessment that has to be taken in to account for some parasites (or diseases) where the symptoms may be so mild or not even present, and therefore a decision may be made not to treat the disease given that the risk outweighs the benefits.
In some cases of pinworm detection in reptiles, medical treatment may not be advised once the risk assessment has be established. This is very different from the presence of parasites in cats or dogs, where most of the species found can cause disease in humans, including tapeworms, roundworms and protozoans. Most of the parasites we detect in captive reptiles are not zoonotic (will not cause disease in humans).
When medications are commercially available they will reach a much higher number of individuals within a much more diverse population and therefore the continued monitoring of adverse events is extremely important.
Animal health companies that market veterinary products have the legal obligation to record and report any adverse events. Vets, doctors, pharmacists, farmers and the general public have the opportunity to report adverse events so that we can all work together on the safety of animals and humans.
A Suspected Adverse Reaction (SAR) is an adverse event that involves the development of side effects in animals or humans after any use of a veterinary medicine.
The Veterinary Medicines Directorate (VMD) is the veterinary medicines regulator in the United Kingdom (UK) and they have quoted ‘the chance of an adverse event happening in any particular animal or person is very low’.
The regulatory framework in the UK governs veterinary pharmacovigilance activities through the UK Veterinary Medicines Regulations 2013 and Volume 9B guidelines. The Market Authorisation Holders (MAHs) have the obligation to present Periodic Safety Update reports (PSURs) every 6 months for the first 2 years, then yearly for 2 years, then every 3 years. The report lists all the suspected adverse reactions reported to the company since the last PSUR. The report places suspected adverse events in context by looking at the incidence of reactions, taking account of the number of doses sold. PSURs provide a concise assessment and evaluation of the current safety profile of the product.
Although the VMD has the authority to withdraw products or specific batches of medicines from the market if required, this is a very rare occurrence. Nevertheless, the possibility to do so provides further assurance of the safety and efficacy of animal medicines on the UK market.
A Suspected Lack of Expected Efficacy (SLEE) is when a veterinary medicinal product is not thought to have worked as well as expected. There are ongoing studies, even in exotic animal medicine with regarding efficacy and resistance of parasites and other pathogens.
References and Further Reading
Veterinary Medicines Directorate (VMD) - Owners Handout
Veterinary Medicines Directorate (VMD) - Reporting Form for Veterinarians
Download/Print (Vets): https://www.aht.org.uk/wp-content/uploads/2018/11/Vaccine_Adverse_Event_Reporting_Form_.pdf
Online (Vets and Owners): https://www.vmd.defra.gov.uk/adversereactionreporting/Product.aspx?SARType=Animal
Veterinary Medicines Directorate (VMD) - The Law
https://www.gov.uk/guidance/veterinary-pharmacovigilance-your-responsibilities
European Medicines Agency (EMA) veterinary pharmacovigilance information
World Health Organisation (WHO) pharmacovigilance definition and information
who.int/medicines/areas/quality_safety/safety_efficacy/pharmvigi/en/
Veterinary Pharmacovigilance in the United Kingdom, VMD Annual Review 2018
The Veterinary Medicines Regulations, 2013 (Schedule 1, Part 8)
legislation.gov.uk/uksi/2013/2033/contents/made
Vol 9b of The Rules Governing Medicinal Products in the European Union – Guidelines on Pharmacovigilance for Medicinal Products for Veterinary Use
http://ec.europa.eu/health/files/eudralex/vol-9/vol_9b_2011-10.pdf
Directive 2001/82/EC on the Community code related to veterinary medicinal products
http://ec.europa.eu/health/files/eudralex/vol-5/dir_2001_82/dir_2001_82_en.pdf
Regulation (EC) No 726/2004 laying down Community procedures for the authorisation and supervision of medicinal products for human and veterinary use and establishing a European Medicines Agency
http://eurlex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2004:136:0001:0033:en:PDF