[Federal Register Volume 62, Number 24 (Wednesday, February 5, 1997)]
[Rules and Regulations]
[Page 5319]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-2821]


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DEPARTMENT OF HEALTH AND HUMAN SERVICES
21 CFR Part 520


Oral Dosage Form New Animal Drugs; Ivermectin Chewables

AGENCY: Food and Drug Administration, HHS.

ACTION: Final rule.

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SUMMARY: The Food and Drug Administration (FDA) is amending the animal 
drug regulations to reflect approval of a new animal drug application 
(NADA) filed by Merck Research Laboratories, Div. of Merck & Co., Inc. 
The NADA provides for veterinary prescription use of ivermectin 
chewables in cats for the prevention of feline heartworm disease for a 
month after infection and removal and control of certain hookworm 
infections.

EFFECTIVE DATE: February 5, 1997.

FOR FURTHER INFORMATION CONTACT: Marcia K. Larkins, Center for 
Veterinary Medicine (HFV-112), Food and Drug Administration, 7500 
Standish Pl., Rockville, MD 20855, 301-594-0614.

SUPPLEMENTARY INFORMATION: Merck Research Laboratories, Div. of Merck & 
Co., Inc., P.O. Box 2000, RY32-209, Rahway, NJ 07065-0914, filed NADA 
141-078 that provides for oral use on veterinary prescription of 
Heartgard<SUP>TM for Cats (ivermectin chewables) to prevent feline 
heartworm disease by eliminating the tissue stage of heartworm larvae 
Dirofilaria immitis for a month after infection and for the removal and 
control of adult and immature (L4) hookworms Ancylostoma tubaeforme and 
A. braziliense. The NADA is approved as of December 23, 1996, and the 
regulations are amended by revising 21 CFR 520.1193 to reflect the 
approval. The basis of approval is discussed in the freedom of 
information summary.
    Under section 512(c)(2)(F)(ii) of the Federal Food, Drug, and 
Cosmetic Act (21 U.S.C. 360b(c)(2)(F)(ii)), this approval qualifies for 
3 years of marketing exclusivity beginning December 23, 1996, because 
the NADA contains substantial evidence of the effectiveness of the drug 
involved, any studies of animal safety required for approval and 
conducted or sponsored by the applicant.
    In accordance with the freedom of information provisions of 21 CFR 
part 20 and 514.11(e)(2)(ii), a summary of safety and effectiveness 
data and information submitted to support approval of this application 
may be seen in the Dockets Management Branch (HFA-305), Food and Drug 
Administration, 12420 Parklawn Dr., rm. 1-23, Rockville, MD 20857, 
between 9 a.m. and 4 p.m., Monday through Friday.
    The agency has carefully considered the potential environmental 
effects of this action. FDA has concluded that the action will not have 
a significant impact on the human environment, and that an 
environmental impact statement is not required. The agency's finding of 
no significant impact and the evidence supporting that finding, 
contained in an environmental assessment, may be seen in the Dockets 
Management Branch (address above) between 9 a.m. and 4 p.m., Monday 
through Friday.

List of Subjects in 21 CFR Part 520

    Animal drugs.
    Therefore, under the Federal Food, Drug, and Cosmetic Act and under 
authority delegated to the Commissioner of Food and Drugs and 
redelegated to the Center for Veterinary Medicine, 21 CFR part 520 is 
amended as follows:

PART 520--ORAL DOSAGE FORM NEW ANIMAL DRUGS

    1. The authority citation for 21 CFR part 520 continues to read as 
follows:

    Authority: Sec. 512 of the Federal Food, Drug, and Cosmetic Act 
(21 U.S.C. 360b).

    2. Section 520.1193 is amended by revising the section heading and 
paragraph (a), and by adding new paragraph (d) to read as follows:

Sec. 520.1193  Ivermectin tablets and chewables.

    (a) Specifications--(1) Dogs. Each tablet or chewable contains 68, 
136, or 272 micrograms of ivermectin.
    (2) Cats. Each chewable contains 55 or 165 micrograms of 
ivermectin.
* * * * *
    (d) Conditions of use in cats--(1) Amount. Up to 2.3 kilograms (up 
to 5 pounds), 55 micrograms; 2.3 to 6.8 kilograms (5 to 15 pounds), 165 
micrograms; over 6.8 kilograms (15 pounds), a combination of the 
appropriate chewables (recommended minimum dose of 24 micrograms of 
ivermectin per kilogram of body weight (10.9 micrograms per pound).
    (2) Indications for use. To prevent feline heartworm disease by 
eliminating the tissue stage of heartworm larvae Dirofilaria immitis 
for a month (30 days) after infection, and for removal and control of 
adult and immature (L4) hookworms Ancylostoma tubaeforme and A. 
braziliense.
    (3) Limitations. For use in cats 6 weeks of age and older. 
Administer once a month. The initial dose must be given within a month 
after cats first exposure to mosquitoes. The final dose must be given 
within a month after the cats last exposure to mosquitoes. Federal law 
restricts this drug to use by or on the order of a licensed 
veterinarian.

    Dated: January 28, 1997.
Michael J. Blackwell,
Deputy Director, Center for Veterinary Medicine.
[FR Doc. 97-2821 Filed 2-4-97; 8:45 am]
BILLING CODE 4160-01-F