The FDA said that there are nearly 100 approved animal drug applications for “medically important” antimicrobials without a defined duration of use. This means the labelling does not include information about how long a product can be administered for.
The draft guidance #273 entitled “Defining Durations of Use for Approved Medically Important Antimicrobial Drugs Fed to Food-Producing Animals” will provide recommendations on how animal drug suppliers may voluntarily establish a defined duration of use for certain approved medically important antimicrobial animal drugs.
This latest attempt to target AMR follows the US FDA guidance published at the end of 2022 which assessed the risk of AMR in humans, which could result from the use of medically important antimicrobial drugs in food producing animals.
The aim of this latest guidance is to better target when and for how long a drug may be used to effectively treat, control, or prevent disease, while minimising the extent of antimicrobial drug exposure.
This is closing an important loophole as all approved uses of medically important antimicrobial drugs in other dosage forms (e.g., injectable, intermammary, tablet, etc.) already have appropriately defined durations of use.
The guidance proposes that labelling should be revised to give information on when to begin and end feeding but instructions such as ‘feed until market weight’ or stop feeding at a certain age should not be used.
The FDA is accepting public comments until 26 December 2023.
While this is voluntary, the FDA has said it will monitor progress over a three-year period to assess whether changes are being adopted. If after three years it determines that adequate progress has not been made it will consider further action under the existing provisions of the Food, Drug & Cosmetic Act.
More recently the animal health sector has been recognised as continuing to move towards more responsible use of antimicrobials. A report from The World Organisation for Animal Health (WOAH) found that antimicrobial use in animals has declined by 13% in three years.
These initiatives come as concerning associations have been made between microplastic contamination in soil and the spread of antibiotic resistant bacteria by researchers.
UK to conduct AMR study on pigs
The Animal and Plant Health Agency (APHA), an executive agency of the Department for Environment, Food and Rural Affairs, is to conduct a study to determine persistence of antimicrobial resistant bacteria on pig and cattle farms using low quantities of antimicrobials. The use of antibiotics in animal feed was banned in the UK and Europe in 2006, although use is allowed for use on sick or diseased animals.
The APHA said research findings suggest that antimicrobial resistant bacteria can persist on livestock premises even after the use of antibiotics has been reduced. This work will explore the length of time that resistance to different antimicrobials remains on farm even after usage is reduced.
