Current status:
European Commission final decision


On 11 July 2007, France presented to the EMEA a referral under Article 35 of Directive 2001/82/EC, as amended, concerning Tribrissen Oral Paste for Horses (including associated names) and authorised products for which this product served as a reference product, containing trimethoprim and sulfadiazine as active ingredient.

France considered that the dosing regime of the product is not correct. It considered that this may lead to lack of efficacy and furthering resistance development in target pathogens, which could possibly lead to risks to human health where zoonotic bacteria are concerned.

The CVMP started the referral procedure during its meeting of 10-12 July 2007. The Marketing Authorisation Holders were requested in a list of questions to provide:

  • Justification of the recommended dose for each of the indications claimed in relation to efficacy and potential selection of antimicrobial resistant bacteria.
    • Part I Summary of the dossier, including the Summary of Product Characteristics, the expert reports and the quantitative and qualitative composition of the product;
    • If applicable, Part IV Efficacy information, including information on pharmacokinetics, pharmacodynamics and anti-microbial resistance data.
    • The Periodic Safety Update Reports for at least the last 3 years.
  • Justification of the withdrawal period, in case the recommended dose should increase.

Marketing Authorisation Holders submitted written responses, defending the authorised dose of 1x30 mg/kg body weight per day for all indications but suggesting a higher dose may be required in the case of salmonellosis. Neither the Periodic Safety Update Reports of the products nor the literature presented included reports of lack of efficacy in the field. Having assessed the responses, the CVMP concluded that:

  1. The efficacy of a dose of 1x30 mg/kg body weight per day to be administered over a maximum period of 5 days has been substantiated for all indications, except for salmonellosis.
  2. There is no documented evidence of problems relating to lack of efficacy or any change in the resistance situation of the relevant target pathogens that would constitute a concern relating to animal or human health.
  3. No dose could be established for the treatment of salmonellosis.
  4. The use of the product should be based on susceptibility testing and take into account official and local antimicrobial policies.
  5. The established withdrawal periods are safe and can be retained.

The CVMP recommended varying the Marketing Authorisations of the concerned veterinary medicinal products in accordance with the conclusions where applicable.

The CVMP Opinion was adopted on 12 December 2007 and the subsequent Commission Decision on March 2008.

Key facts

Approved name
International non-proprietary name (INN) or common name
trimethoprim and sulfadiazine
Reference number
Article 35

Community interest referral: initiated in cases involving the interests of the Community or concerns relating to the protection of human or animal health or the environment.

European Commission final decision
Opinion date
EC decision date

All documents

Document description

  • Opinion - contains the CVMP opinion of the referred medicine(s)
  • List of the medicines affected by the referral (Annex I)
  • Scientific conclusions of the Committee (Annex II)

The following two documents may not always be available:

  • Changes to the summary of product characteristics, labeling or package leaflet ('annex III') - available when changes have been recommended by the Committee
  • Conditions of the marketing authorisation (Annex IV) - available when the Committee recommends measures to be taken for the marketing authorisation(s) such as safety measures or extra studies

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