Veterinary Feed Directive (VFD) Drugs
The federal Animal Drug Availability Act of 1996 (ADAA) amended the federal Food, Drug and Cosmetic Act (FD&C) to establish a new category of drugs; veterinary feed directive (VFD) drugs. A drug intended for use in or on feed, which is limited by an approved application to use under the professional supervision of a licensed veterinarian is a VFD drug. Proposed regulations covering the use and distribution of VFD feeds (medicated feeds containing VFD drugs) were published in the Federal Register of July 2, 1999. The final rule was published in the Federal Register of December 8, 2000 and became effective on January 8, 2001.
In the past, drugs used in animal feeds were approved as over-the counter (OTC) drugs. While the FD&C did not prohibit approval of prescription drugs for use in animal feeds, such approvals were impractical because some states' pharmacy laws required a licensed pharmacist to dispense the drugs, while other states prohibited feed manufacturers from possessing and dispensing prescription drugs. The VFD solves this problem by allowing the veterinarian to order the use of VFD drugs in feed without the involvement of a pharmacist in the manufacture of medicated animal feed. The required involvement of a veterinarian satisfies FDA's concerns that the drugs be used only in appropriate circumstances and under greater control than with OTC drugs.
The VFD process is straightforward in practice. A veterinarian, operating within the confines of a veterinarian-client-patient relationship, examines and diagnoses animal conditions and determines whether any of those conditions warrants use of a VFD drug. If it does, the veterinarian will issue a signed VFD containing information specified by regulation. The veterinarian keeps a copy of the VFD and provides the completed and signed original and a copy to the client. The client keeps the copy and gives the original VFD to the feed manufacturer. The VFD authorizes the VFD feed to be shipped to the client's animal feeding operation. While not specifically required, FDA believes the drug manufacturers will provide preprinted "fill-in-the-blank" triplicate VFD forms to the veterinary profession for the sake of efficiency and accuracy. This has been done with tilmicosin and florfenicol, the two approved VFD drugs to date.
The ADAA has a statutory requirement that anyone intending to distribute VFD feeds notify FDA’s Center for Veterinary medicine (CVM) prior to beginning distribution (the notification process is explained on page 9 of the FDA Guidance for Industry #120”). Distributor includes the VFD feed manufacturer or anyone else in the distribution chain that ultimately supplies VFD feed to an animal producer. This could include the veterinarian if he is the source of VFD feed. A VFD feed may not be distributed to a client without a signed VFD. However, VFD feed may be sent down the distribution chain if the consignee provides the distributor with a signed "acknowledgment" letter affirming that it will only ship the VFD feed to a VFD holder or to another distributor who supplies a similar acknowledgment letter. Feed manufacturers or any distributor may stockpile VFD feeds in anticipation of orders.
CVM recognizes that there are instances when direct contact among the veterinarian, client and feed distributor is not practical. To counter this problem and facilitate rapid movement of VFD feeds, CVM is permits transmission of the VFD by facsimile or other electronic means provided safeguards are in place to prevent misuse.
Another area of concern is the length of time a VFD may be valid (its expiration date) and the number of refills or reorders that may be allowed. Limits must be placed on the length of time a VFD is valid and/or amount of animals that can be treated. FDA believes there are situations when refills and expiration dates, possibly of several months, are appropriate to medicate multiple production groups and provide efficient treatment of sick animals. FDA further believes allowances of this type will vary considerably. Since it cannot be predicted what types of drugs and disease situations will be presented in the future, the issue of refills and reorders and the duration of time a VFD order is valid will be considered on a drug-by-drug basis as part of the new animal drug approval process.