EVALUATION OF ANTIBIOTIC RESIDUE SCREENING TESTS WITH MILK OF INDIVIDUAL COWS
ANALYSIS OF TETRACYCLINES IN MILK AND OTHER FOOD PRODUCTS OF ANIMAL ORIGIN
FEED MILL LICENSING PROPOSED RULE PUBLISHED
On July 30, 1997, FDA published a proposed rule to amend the animal drug regulations and add a new Part 515 to provide for feed mill licensing in accordance with the Animal Drug Availability Act (ADAA) of 1996. The intent of the proposed rule is to reduce the paperwork imposed on manufacturers of medicated feed and FDA while maintaining current safeguards for the manufacture of medicated feed.
The licensing of feed mills is required by the ADAA to replace the previous system of regulating medicated feed. The former process required the approval of a medicated feed application (MFA) for certain medicated feeds. The ADAA eliminates the requirement that a feed mill submit a separate MFA for the manufacture of each type of medicated feed and instead provides for feed mills to be licensed and allows a licensed facility to manufacture any feed containing an approved new animal drug. The proposed rule deletes the procedural regulations that provided specifically for medicated feed applications in 21 CFR 514 and establishes regulations for feed mill licensing in a new section, 21 CFR 515.
The ADAA grants a transitional license to all feed manufacturing facilities currently holding an approved MFA. This transitional license expires April 9, 1998. These firms can obtain a permanent license by submitting a license application with a copy of an approved MFA to FDA. Feed manufacturers are still subject to the current good manufacturing practices regulations and inspection by State or FDA. All other existing reporting responsibilities for each drug remain unchanged.
Feed facilities that want a license and do not hold an MFA need to submit a license application (Form FDA 3448) to FDA and undergo a preapproval inspection. If the facility is in compliance with good manufacturing practices, FDA will issue the license.
A copy of the proposed rule can be obtained from the CVM Home Page or by calling CVM's Communications Staff at 301-594-1755.
Written comments on the proposed rule must be received by October 28, 1997. All comments should be sent to the Dockets Management Branch (HFA-305), Food and Drug Administration, 12420 Parklawn Drive, Room 1-23, Rockville, MD 20857. Comments may also be faxed to the Dockets Management Branch on 301-594-3215. Please identify comments with the Docket Number 97N-0276.
Further information on the proposed rule is available in the Federal Register and from Dr. William D. Price, Center for Veterinary Medicine (HFV-200), 7500 Standish Place, Rockville, MD 20855, 301-594-1724.
FDA REQUESTS THAT ETHOXYQUIN LEVELS BE REDUCED IN DOG FOODS
In letters dated July 31, 1997, to manufacturers of ethoxyquin and trade associations for the pet food industry, FDA's Center for Veterinary Medicine (CVM) requested that the maximum level for ethoxyquin in complete dog foods be voluntarily lowered to 75 parts per million (ppm). Under the current food additive regulations, ethoxyquin is allowed at levels up to 150 ppm in complete dog foods (Title 21, Part 573.380 of the Code of Federal Regulations). However, after recently completing a scientific review of a voluntarily-submitted study from the Monsanto Company, CVM has reason to believe that the 150 ppm level may not provide an adequate margin of safety in lactating female dogs and possibly puppies. The results from this study show that ethoxyquin levels above the current tolerance in dog foods produced no adverse reproductive effects. There was, however, an increase in a dark, reddish-brown pigment in the liver of female dogs immediately after completing a 6-week lactation. The liver pigment was identified as protoporphyrin IX, a normal intermediate in the synthesis of heme. This pigment was also associated with elevations in liver-related enzymes in the serum of a few animals.
During lactation, the female dogs consumed two to three times more food as a percentage of body weight than they did at maintenance, and this increased food consumption likely contributed to the increased pigment deposition in the liver and in the elevated serum enzymes. The increased pigment deposition and serum enzymes in lactating female dogs may be reversible when food consumption returns to maintenance, but it still constitutes a finding that must be further investigated.
The Pet Food Institute has undertaken a study designed to show that ethoxyquin is an effective antioxidant at levels between 30 and 60 ppm in a complete dog food. FDA is closely monitoring the progress of this study. If new information becomes available that questions the safety of ethoxyquin at 75 ppm in dog food, or shows it to be an effective antioxidant at levels below 75 ppm, CVM will consider further action.
Further information on this subject is available from FDA/CVM's Division of Animal Feeds, 7500 Standish Place, HFV-220, Rockville, MD 20855 or by calling (301) 594-1724.
1996 ADVERSE DRUG EXPERIENCE SUMMARY
This issue of the FDA Veterinarian contains a pull-out section of the first installment of the 1996 Veterinary Adverse Drug Experience Summary. This summary includes all domestic adverse drug reaction reports submitted to CVM for calendar year 1996 that the Center has determined to be at least possibly drug related. It should be noted that the human reports are almost always associated with accidental exposure.
This report indicates when products are used in an extra-label manner, i.e., in a species for which they are not approved, at the wrong dosage levels, etc. Readers can note extra-label use by the abbreviation ELU along with the specific type of extra-label use involved. Thus, if an individual report indicates that the drug was used for a species not included in the labeling directions, the listing will indicate ELU-species.
A new member has been appointed to FDA's Veterinary Medicine Advisory Committee (VMAC). Dr. Frederick J. Angulo will attend the Fall VMAC meeting in his official capacity representing the specialty of Public Health and Epidemiology.
Dr. Angulo is currently a Medical Epidemiologist in the Division of Bacterial and Mycotic Diseases at the Centers for Disease Control and Prevention in Atlanta, Georgia. He received his D.V.M., M.S., and Ph.D. degrees from the University of California. Dr. Angulo is a member of the U.S. Army Veterinary Corps, with previous duty in North Carolina, Maryland, Italy, and Belgium. In addition, Dr. Angulo is a Diplomate of the American College of Preventive Veterinary Medicine with an Epidemiology Specialty.
Dr. Donald Lein is the chairman of VMAC, which usually meets twice a year. Other members include Dr. George Cooper, Sue Hudson Duran, Dr. Diane Gerken, Dr. Gary Koritz, Dr. Alice Wolf, Dr. Steven Barker, Col. Nancy Jaax, Dr. Ling-Jung Koong, Dr. Oscar Fletcher, and Dr. Keith Sterner. VMAC members normally serve four-year terms.
EVALUATION OF ANTIBIOTIC RESIDUE SCREENING TESTS WITH MILK OF INDIVIDUAL COWS
by Suzanne Sechen, Ph.D.
This information was presented as a poster at the American Dairy Science Association annual meeting held June 22-25, 1997, at the University of Guelph.
Background
The dairy industry has a profound interest in producing high quality dairy products free of antibiotic residues. Similarly, antibiotic residues in milk are a food safety concern to the FDA's Center for Veterinary Medicine. To this end, the National Conference on Interstate Milk Shipments (NCIMS) at their 1991 biennial meeting passed a resolution modifying the Grade A Pasteurized Milk Ordinance (PMO). This change in the PMO, identified as Appendix N, requires milk in bulk pick-up tankers to be tested for -lactam antibiotic residues prior to entering the food supply. In addition, CVM, in cooperation with AOACRI, began evaluating rapid screening tests for detection of antibiotics in raw, bulk, commingled milk.
Some have chosen to extend the acceptance of milk antibiotic screening tests by FDA and NCIMS to the detection of antibiotic residues in milk from individual animals, i.e., "cowside" use. Furthermore, use of screening tests to reliably detect antibiotics at violative concentrations in the milk of individual cows is encouraged in milk residue avoidance programs. However, high rates of false positive outcomes have been reported for several antibiotic screening tests when used with milk from individual cows.
Both false positive and false violative test results may result in discarded milk that is legal to sell, representing an economic loss to the producer. On the other hand, the FDA and the dairy industry must also be concerned with the incidence of false negative test results to ensure public health and avoid contamination of bulk tank milk.
Approach
In response to concerns regarding the reliability of milk screening tests for use with milk from individual cows, CVM developed a protocol for their evaluation. The studies were managed by CVM and conducted under an Interagency Agreement with the USDA Immunology and Disease Resistance Laboratory in Beltsville, Maryland. Only screening tests accepted by FDA and NCIMS for bulk milk were evaluated.
The first phase of the protocol called for the demonstration that a test provide a selectivity rate of at least 90 percent on zero residue (control) milk that is visually normal and from healthy cows with a confidence of at least 95 percent. Selectivity rate refers to the percentage of truly negative samples found by a screening test to be negative. Of the 9 ß-lactam screening tests initially evaluated, all of them met this criterion.
The second phase of the protocol included the evaluation of screening tests in visually normal milk of cows recovering from an intramammary endotoxin challenge, which was used as a model for clinical mastitis. Several components in mastitic milk have been implicated as interferants in various antibiotic residue screening tests, including somatic cells, lactoferrin, lysozyme, and bacteria. The protocol required that a screening test meet the 90 percent standard for selectivity when used with visually normal milk from cows recovering from endotoxin challenge. In addition, a test must provide at least a 90 percent sensitivity rate (with 95 percent confidence) with visually normal milk following endotoxin challenge for the drugs that the test is intended to detect. That is, a test must detect at least 90 percent of truly positive samples.
The current study represented the second phase of the protocol. The objective of this study was to evaluate the performance of 9 -lactam screening tests with visually normal milk of cows recovering from intramammary endotoxin challenge.
Materials and Methods
Thirty lactating Holstein cows in their first through fourth lactation and ranging from 57 to 339 days into lactation were selected from the USDA dairy herd in Beltsville, Maryland. The cows had received no antibiotic therapy 30 days prior to, or during, the study. They were free of major intramammary pathogens, and at least one udder quarter was free of both major and minor intramammary pathogens.
Two or 3 cows per week were each infused in one quarter with 10 ug endotoxin in 2 ml sterile saline. Unfortified total composite milk from the milking prior to endotoxin challenge and the first visually normal milk after endotoxin challenge was analyzed by each screening test. If the outcome of a screening test performed with a cow's first visually normal milk following endotoxin challenge and unfortified with antibiotics was positive, that screening test's analyses were repeated with the animal's milk from the subsequent milking.
Screening test analyses were also performed on subsamples of the first visually normal milk fortified separately with each -lactam antibiotic for which a screening test was labeled. Final concentrations of -lactam antibiotics included the FDA tolerance or safe level and the screening test's estimated 90 percent sensitivity level for raw milk.
The 9 screening tests evaluated were: Charm Bacillus stearothermophilus Tablet Disc Assay (BsDA); Charm I/Cowside II® Tablet Beta-lactam Test (Sequential Assay); Charm II® Tablet Beta-lactam Test (Sequential Assay); Delvotest® P Mini ampule test; Delvotest® SP Mini ampule test; LacTek™ B-L (beta-lactam) Milk Screening Kit; LacTek™ CEF(Ceftiofur) Milk Screening Kit; Penzyme® Milk Test; and Snap™ Beta-Lactam Test Kit.
Results and Conclusions
Complete results of this study will be published in a scientific journal. A summary of results and conclusions include:
Intramammary endotoxin challenge of cows resulted in symptoms similar to clinical mastitis: visually abnormal milk, reduced milk production, increased milk somatic cell count, and increased body temperature.
All 9 screening tests evaluated passed the 90 percent selectivity criterion as defined by CVM for cows recovering from an intramammary endotoxin challenge: unfortified samples from the first or second milking with visually normal milk did not produce a positive outcome. Thus, lengthy periods of false positive results were not observed.
In 6 screening tests, false negative results were recorded in cows' first normal appearing milk fortified at the FDA tolerance/safe level with ß-lactam antibiotics for which the screening test is labeled, i.e., these tests failed the 90 percent sensitivity criterion for these antibiotics. False negative results are of great concern from the standpoint of public health. In addition, false negative outcomes might result in a producer commingling a cow's violative milk with the milk of herdmates and potentially contaminating the entire bulk tank.
In contrast, several screening tests could detect specific antibiotics at levels well below the FDA tolerance/safe levels in milk.
To validate the accuracy of the endotoxin challenge model to evaluate antibiotic screening tests for use on an individual cow basis, it would be useful to conduct a similar type of study with milk of dairy cows recovering from "naturally" occurring clinical mastitis caused by a variety of common mastitic organisms.
Producers need to use information available to decide which screening tests are most appropriate for the antibiotic used to treat an animal to prevent contamination of commingled herd milk, yet not discard the animal's milk once it is legal for sale.
STUDENTS LEARN THE ROPES ABOUT CVM
CVM sponsors a scientific academic outreach program in collaboration with NIH (National Institutes of Health) and FAES (Foundation for Advanced Education in the Sciences) to provide training opportunities for undergraduate, graduate and professional students. The program seeks to promote personal development and professional skills reflective of the students' field of study, with the ultimate goal of pursuing careers significant to the Center.
There were four individuals in CVM's 1997 Student Intern Program, each assigned to a scientific mentor. Ramat Arogundade, a student at Howard University Medical School, researched the number of drug residue violations in different slaughter classes of animals for the Division of Epidemiology and Surveillance. Ebony Bookman, a Howard University Graduate Student assigned to the Division of Biometrics and Production Drugs, evaluated the efficacy and effect on carcass quality of a growth promotant combination. Kristi Pullen, a student at the University of Maryland Baltimore County, studied the maximum tolerable levels of vanadium in ruminant rations in the Division of Animal Feeds. Oladotun Okunola, a student at Howard University Medical School assigned to the Office of Research, studied the adaptation and validation of methods for measuring stress and inflammation for use in domestic animals.
Students must have a 3.6 grade point average to qualify for the Intern Program. Each participating CVM Research/Review Scientist is asked to provide a Student Intern Project that includes a plan stating the objectives and a critical evaluation plan to be conducted at four-week intervals. It is recommended that the mentor meet with the student on a weekly basis to best provide the mid-term and final evaluations.
The Center for Veterinary Medicine has long been a supporter of the Summer Intern Program, as it promotes youth, vigor, new ideas, and carries out projects beneficial to both the Center's mission and the students.
For further information about CVM's Student Intern Summer Program, please contact Dr. Woodrow M. Knight at 301-827-0219 and/or Mrs. Bessie M. Cook at 301-594-1792.
ANALYSIS OF TETRACYCLINES IN MILK AND OTHER FOOD PRODUCTS OF ANIMAL ORIGIN
by Mary C. Carson, Ph.D.
Tetracyclines are widely used in veterinary practice for both therapeutic and prophylactic purposes. Screening tests are often the first line of food safety monitoring for the presence of unsafe residues of these drugs in milk. They are simple, inexpensive, and can usually be performed at the dairy or slaughterhouse, but are much less specific than the other two types of assays and usually cannot give information about how much residue is present. To support regulatory actions the Agency may take, specific multiresidue chemical procedures for tetracycline determination and confirmation are required. Determinative procedures measure the amount of a suspected residue in a food product. Confirmatory procedures provide highly specific, unambiguous identification of that residue; these assays frequently use mass spectrometry. Chemical tetracycline determinative procedures are also used as the reference analyses for certification of bulk tank milk tetracycline screening tests.
The FDA's first nationwide survey for multiple antibiotic residues in shelf milk was conducted in late 1989 and early 1990. This survey was initiated because newly developed screening assays were testing positive on milk available to the consumer at retail stores. The initial survey included analyses for chloramphenicol, eight different sulfonamides, and three tetracycline drugs (tetracycline, oxytetracycline, and chlortetracycline). Although FDA chemists found no unsafe residues in any of the milk samples, naturally occurring interferences in milk limited the analysis of tetracyclines to residues present at more than 100 parts per billion. CVM's Office of Research (formerly CVM's Office of Science) was asked to develop and validate determinative and confirmatory procedures for tetracyclines that could be used to identify and measure residues at 30 parts per billion or lower. This meant that the new method needed to have a limit of detection of 10 parts per billion or less. Additionally, the new method had to include as many other commercially available tetracyclines as possible.
Four additional members of the tetracycline family of antibiotics, minocycline, doxycycline, methacycline, and demeclocycline, were readily analyzed using the same chromatographic conditions as the original procedure. Lowering the limit of detection from 100 parts per billion to less than 10 parts per billion was not as easy. A major milk vitamin, riboflavin, structurally resembles tetracyclines and interfered with the analysis. Fortunately, 1990 was also the year of the first Euroresidue meeting. Dr. William Farrington, of the United Kingdom's Ministry of Agriculture, Fisheries, and Food, presented a procedure he developed for tetracyclines in meat that had a limit of detection below 10 parts per billion. This procedure took advantage of tetracyclines' ability to bind to metal ions. The extraction process provided an extract free of interferences. CVM adapted the tissue extraction for the analysis of the seven tetracyclines in milk. The limit of detection was below five parts per billion for all the drugs and near one part per billion for oxytetracycline.
This procedure was validated within CVM using control, fortified, and incurred milk (milk from cows treated with the drugs), and by an independent second analyst using control and fortified milk. The milk procedure was published in 1993 in the Journal of AOAC International. The procedure was further validated in an interlaboratory AOAC collaborative study from 1992 to 1994. The ten participating laboratories included FDA field laboratories, state laboratories, an academic laboratory, and Dr. Farrington's United Kingdom laboratory. The analysts assayed control and fortified milk samples, and 18 unknown samples containing a variety of incurred residues. The collaborative study was successful and resulted in AOAC International adopting the procedure as an Official Method.
The multiresidue determinative procedure for tetracyclines in milk is now used by several of the states in their milk monitoring programs. It is also used by the FDA's Denver District Office in the National Drug Residue Milk Monitoring Program and is the reference method for analysis of incurred residue milk samples used for certification of screening tests for tetracyclines in milk. Use of certified screening tests has reduced the incidence of false positives while still preventing milk containing unsafe residues from reaching the consumer.
The extraction used in the determinative assay was scaled up and refined to enable mass spectral confirmation of tetracycline residues in milk. Mass spectral analysis essentially provides a chemical "fingerprint." The confirmatory procedure unambiguously identifies residues of oxytetracycline, tetracycline, chlortetracycline, doxycycline, demeclocycline, and minocycline in milk at concentrations of 30 parts per billion and above.
While CVM was developing and validating the milk tetracycline confirmatory procedure, the FDA's Seafood Products Research Center in Seattle was developing and validating a determinative procedure for oxytetracycline in shrimp. Aquaculture (seafood farming) produces more than 50 percent of the shrimp consumed by people. Oxytetracycline is used in the shrimp industry to treat bacterial diseases. Determinative and confirmatory procedures are required both to support a New Animal Drug Approval for oxytetracycline in shrimp and to enable monitoring for residues in shrimp intended for human consumption. CVM chemists modified the multiresidue milk tetracycline confirmatory procedure to allow confirmation of oxytetracycline residues in shrimp. The Seafood Products Research Center provided tissue from control white shrimp and shrimp that had been treated with oxytetracycline. This cooperative effort of two laboratories on opposite sides of the U.S. allowed the rapid (< one month) development and validation of a confirmatory procedure for oxytetracycline in shrimp.
The author was named by the AOAC Methods Committee on Drugs and Related Topics as their 1995 Associate Referee of the Year. She was also CVM's 1996 nominee for the FDA Excellence in Analytical Science Award.
On page 11 of the July/August issue of the FDA Veterinarian, the fifth reference cited in the article titled "Drug Residues in Food-Producing Animals" -- the author's name should read "Wilcke, J.R." not "Wilcke, Jr."
In the July 27, 1997 Federal Register, FDA published a notice stating that the Agency is withdrawing approval of a new animal drug application (NADA 46-147) for diethylcarbamazine citrate syrup (Dirocide). This NADA was held by Babineaux's Veterinary Products, Inc. The sponsor requested the withdrawal of approval because the product is no longer being marketed.
Also in the July 27, 1997 Federal Register, FDA published a notice stating that the Agency is withdrawing approval of new animal drug applications (NADA 48-391 and 49-183) for phenylbutazone injection and oxytocin injection. These NADAs were held by Schein Pharmaceutical, Inc./Steris Laboratories, Inc. The sponsor requested the withdrawal of approval because the products are no longer being marketed.
In the July 15, 1997 Federal Register, FDA published a notice stating that the Agency is withdrawing approval of a new animal drug application (NADA 13-029) held by Elanco Animal Health, Division of Eli Lilly and Co. for tylosin soluble powder (Tylan Plus Vitamins). The sponsor requested the withdrawal of approval because the product is no longer being marketed.
The following firms/individuals received warning letters for offering animals for slaughter that contained illegal drug residues:
Joe Kelly, Buchanan, GA
Fred Schisler, New Windsor, MD
Richard Arthur and Ansally Stuyt, Escalon, CA
Martin Vantil, Kerman, CA
Joost Verduyn, Golden West Dairy, Visalia, CA
Peter Veeman, Veeman Dairy, Saint Paul, OR
Galen Clayson, Cedar Arch Dairy, Firth, ID
Terry Weyandt (livestock dealer/hauler), Claysburg, PA
These violations involved illegal residues of oxytetracycline and penicillin in a cow; sulfamethazine in a calf; sulfadimethoxine and penicillin in a cull dairy cow; tetracycline in a cow; gentamicin in a dairy cow; penicillin in a cow; sulfadimethoxine in a dairy cow; sulfamethoxazole, gentamicin, penicillin, streptomycin, and chlortetracycline in calves.
FDA/CVM 1996 VETERINARY ADVERSE DRUG EXPERIENCE SUMMARY
This summary includes all domestic adverse drug reaction reports submitted to the Center for Veterinary Medicine (CVM) for calendar year 1996 which the Center has determined to be at least possibly drug related. It is organized alphabetically by generic drug, and within each drug by species, and within each species by the general route of administration. The Center's adverse drug reaction review process takes into consideration confounding factors such as dosage, concomitant drug use, the medical and physical condition of the animals at the time of treatment, environmental and management information, product defects, extra-label uses, etc. These complex factors, however, cannot be fully addressed in this summary. This summary is intended only as a general reference to the type of reactions that veterinarians, animal owners, and others have voluntarily reported to FDA or the manufacturer after drug use; therefore, it is not by itself a basis for:
Determining drug association for a particular sign
Determining the safety and efficacy of a given drug
Determining the frequency of occurrence of an adverse reaction
Comparing one drug with another drug
Nevertheless, the information in the summary can alert readers to suspected drug effects being reported by their colleagues and sensitize them to potential problems. The report may also serve to stimulate readers to share their own experiences for the benefit of their colleagues and ultimately the improvement of veterinary products.
This summary does not include product failure or adverse reaction reports for biologics and topically applied, externally acting parasiticides. Such reports received by CVM are forwarded to the government agency that regulates the product in question. In addition, it does not include reports of drug product defect reports unless the report also contains adverse reaction information. The human reports involve human exposure to an animal drug.
| Company | Generic and (Brand) Names | Indications | Routes/Remarks |
|---|---|---|---|
| Deprenyl Animal Health, Inc. (NADA 141-080) | Selegiline hydrochloride tablet(Anipryl®) Rx | Dogs. For control of clinical signs associated with uncomplicated pituitary, dependent hyper-adrenocorticism. | ORAL: Each tablet contains either 2, 5, 10, 15, or 30 milligrams of selegiline hydrochloride. Dosage -- 1 milligram per kilogram (0.45 milligram per pound of body weight). Federal Register 6/27/97. |
| Merck Research Laboratories, Division of Merck & Co. (NADA 141-079) | Eprinomectin (Ivomec® Eprinex TM Pour-On) | Cattle. For treatment and control of certain gastrointestinal roundworms, lungworms, cattle grubs, lice, mange mites, and flies. | TOPICAL: Provides for use of Ivomec® Eprinex TM Pour-On (5 milligrams per milliliter eprinomectin). The regulations are also amended to provide for a tolerance for residues of the drug in milk and in edible tissues. Federal Register 6/24/97. |
| Fort Dodge Animal Health, Division of American Home Products Corp. (NADA 141-051) | Moxidectin Tablets (ProHeart®) Rx | Dogs. For prevention of canine heartworm infections and subsequent development of canine heartworm disease. | ORAL: Each tablet contains either 30, 68. or 136 micrograms of moxidectin. Dosage: use once a month at 3 micrograms per kilogram (1.36 micrograms per pound) of body weight. Federal Register 7/15/97. |
ABBREVIATED NEW ANIMAL DRUG APPROVALS
| Company | Generic and (Brand) Names | Indications | Routes/Remarks |
|---|---|---|---|
| Med-Pharmex, Inc. (ANADA 200-190) | Gentamicin sulfate oral solution | Weanling Swine. For control and treatment of colibacillosis and for control and treatment of swine dysentery caused by Treponema hyodysenteriae. | ORAL: ANADA 200-190 is a generic copy of Schering -Plough Animal Health's NADA 91-191 for Garasin (gentamicin sulfate) oral solution. Federal Register 6/25/97. |
SUPPLEMENTAL NEW ANIMAL DRUG APPROVALS
| Company | Generic and (Brand) Names | Indications | Routes/Remarks |
|---|---|---|---|
| Bayer Corp., Agriculture Division, Animal Health (NADA 140-441) | Enrofloxacin (Baytril) Tablets Rx | Dogs and Cats. For management of diseases associated with bacteria susceptible to enrofloxacin. | ORAL: Provides for revised conditions for use by administering tablets orally at a rate of 5 to 20 mg per kilogram (2.27 to 9.07 mg/pound) of body weight as a single daily dose or divided and given in 2 equal daily doses at 12-hour intervals for at least 2 to 3 days beyond cessation of clinical signs, to a maximum of 30 days. Federal Register 7/21/97. |
| Bayer Corp., Agriculture Division, Animal Health (NADA 140-913) | Enrofloxacin (Baytril ® Injectable Solution) Rx | Dogs. For management of diseases associated with bacteria susceptible to enrofloxacin. | INJECTABLE: Provides for revised indications for use of enrofloxacin injectable for dogs for management of diseases associated with bacteria susceptible to enrofloxacin. Federal Register 7/21/97. |
| Merck Research Labs., Division of Merck & Co., Inc. (NADA 140-841) | Ivermectin (Ivomec ®) Pour ON | Cattle. For control of infections of gastro-intestinal roundworms for 14 days following use. | TOPICAL: Provides for use of Ivomec pour-on (5 milligrams of ivermectin per milliliter). Federal Register 7/21/97. |
| Elanco Animal Health, Division of Eli Lilly and Co. (NADA 13-076) | Tylosin | Chickens, Turkeys, and Swine. For control and/or treatment of infections sensitive to tylosin. | ORAL: Provides use of packages containing the equivalent of 100 grams (g) of tylosin to make 50 gallons of chicken and turkey drinking water, and one-half package or 50 g of tylosin to make 200 gallons of swine drinking water, to treat tylosin sensitive infections. The tylosin base soluble powder approved under NADA 13-029 for swine and the tylosin tartrate soluble powder approved under NADA 13-076 for chickens and turkeys, are considered to be DESI-equivalent based on the findings of the National Academy of Sciences/National Research Council review of the products and FDA's conclusions based on that review, and should have been DESI-finalized as one application. The supplement provides for incorporating NADA 13-029 into NADA 13-076 and in a separate action, withdrawing approval of NADA 13-029. Federal Register 7/23/97. |
| Solvay Animal Health (NADA 6-707) | Sulfaquinoxaline | Chickens and Turkeys. For control of coccidiosis, acute fowl cholera, and fowl typhoid. | ORAL: Provides for 28.62 percent sulfaquinoxaline sodium solution to make 0.025 or 0.04 percent solution used in drinking water. Federal Register 7/15/97. |
SUPPLEMENTAL ABBREVIATED NEW ANIMAL DRUG APPROVALS
| Company | Generic and (Brand) Names | Indications | Routes/Remarks |
|---|---|---|---|
| Lambert Kay, Division of Carter-Wallace, Inc. (ANADA 200-028) | Pyrantel pamoate suspension | Puppies and Dogs. For removal of large roundworms and hookworms, and to prevent reinfections of T. canis in puppies and adult dogs and in lactating bitches after whelping. | ORAL: The supplemental ANADA provides for 4.54 milligrams per milliliter (mg/ML) in addition to the 2.27 mg/ML suspension. Federal Register 7/15/97. |
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