In February 2016 the Netherlands and France submitted a class referral to the European Medicines Agency (EMA) for all veterinary medicines containing zinc oxide administered orally to food producing animals. The grounds for the referral were concerns regarding the potential risk that zinc oxide presents to the environment and the risk for co-selection of antimicrobial resistance. In order to evaluate the overall benefit:risk balance for the products, consideration was also to be given to the authorised treatment benefits.
The EMA’s Committee for Medicinal Products for Veterinary Use (CVMP) has now re-evaluated the benefit:risk for this class of products. The CVMP can only address the specific questions posed as part of the referral.
Taking account of the data available in the referral procedure, it was concluded that the treatment benefits of zinc oxide for the prevention of diarrhoea in pigs did not outweigh the environmental risk associated with their use. Effective measures to manage and reduce the accumulation of zinc in the environment could not be identified.
The CVMP also acknowledged that there is a risk of co-selection for resistance associated with the use of zinc oxide, but at the present time, that risk is not quantifiable. Based on its scientific conclusions, the committee recommended withdrawal of the marketing authorisations for the products. All EU Member States (MS) are represented on the CVMP; members from the UK supported the CVMP Opinion.
The full grounds for the CVMP conclusion will be set out in their Opinion, which should be published within the next few months; the press release summary can be found on the EMA website.
Following adoption, the CVMP’s opinion is forwarded to marketing authorisation holders who may, within 15 days of receipt, make a request for re-examination.
The opinion is also forwarded to the MS and the European Commission. Prior to adopting a final decision, the European Commission, in consultation with MS, will consider the impacts on the EU pig farming industry (changes in pig farming practices to avoid increases in the occurrence of diarrhoea at weaning, to ensure animal welfare and prevent increases in the use of antibiotics) at a meeting of the Standing Committee on Medicinal Products for Veterinary Use.
Further information on the referral and Commission Decision-making procedures is available on the EMA website.
Gutal 1000 g/kg premix for medicated feeding stuff for piglets
During a product referral for ‘Gutal 1000 g/kg premix for medicated feeding stuff for piglets’ the environmental risk associated with zinc oxide was examined by the CVMP. This referral related to a specific generic product, and pertained to the environmental risk relating to Gutal only. Data relating to the authorised treatment benefit for the class of zinc oxide products were not re-examined.
The Committee noted in their report for that procedure that; ‘Due to the intrinsic nature of zinc (non-volatile and non-degradable) the potential for Predicted No Effect Concentrations (PNECs) to be eventually surpassed as a result of continual application of manure from treated animals to land over an extended period is a significant environmental concern, particularly with regard to the most vulnerable soil types (acidic, freely draining, sandy soils) and organisms of the aquatic compartments.
It is important to note that CVMP Opinions are based on the scientific evidence available; wider relevant issues such as availability of alternative treatments etc. can be raised during MS engagement with the Commission.
Stakeholders with concerns relating to possible withdrawal of these products can present these, together with supporting evidence, to the VMD (as UK representative on the Standing Committee on Veterinary Medicinal Products) by mid-January 2017.
Authorised products containing zinc oxide
There are three veterinary medicines authorised for oral administration to food producing animals in the UK that contain zinc oxide as their active substance; these are all authorised for use in piglets for the prevention, or treatment and control, of diarrhoea.
Refer to the Product Information Database for details of authorised products.
There are a limited number of vaccines authorised within the EU for the prevention of diarrhoea in piglets, these are indicated for specific pathogens. There are also a number of antibiotics that are authorised either for treatment, or for prevention and treatment, of specific causes of diarrhoea in piglets.