Animal & Veterinary

NADA 140-915 Safeheart™ - supplemental approval (June 4, 1998)

Approval Date: June 4, 1998





Novartis Animal Health US, Inc.
Post Office Box 26402
Greensboro, NC 27404-6402

Generic Name:

Milbemycin Oxime Tablets

Trade Name:


Marketing Status:


Effect of Supplement:

For the prevention of heartworm disease caused by Dirofilaria immitis in dogs and puppies four weeks of age or greater and 2 pounds of body weight or greater.


SAFEHEART™ Tablets are indicated for use in the prevention of heartworm disease in dogs and puppies four weeks of age or greater and two pounds body weight or greater




Oral Tablets



SAFEHEARTä Tablets should be given by direct oral dosing.



SAFEHEARTä Tablets are given orally, once a month, at the recommended minimum
dosage of 0.1 mg milbemycin oxime per kg of body weight (0.05 mg/lb).


Recommended Dosage Schedule


Body Weight Tablet Size
2 -50 lbs. One Tablet (2.3 mg)
50.1 - 125 lbs. One Tablet (5.75 mg)




Dogs over 125 lbs. are provided the appropriate combination of tablets.


Milbemycin oxime is an anthelmintic compound which, when given orally to animals, is effective in eliminating the tissue stage of heartworm larvae. The anthelmintic activity is believed to be a result of interference with invertebrate neurotransmission.

A. Dose Establishment Studies

Dose establishment studies in support of this product are referenced in the Freedom of Information (FOI) Summary for the original NADA 140-915 approval.

B. Well-Controlled Clinical Field Trial

Study No. CAH-4303-95-0096

Purpose: To evaluate the efficacy of milbemycin oxime when administered monthly at a minimum of 0.1 mg/kg by the pet owner for heartworm prevention.

Investigators/Study Locations:

Dr. William Craig
Ingram Park Animal
San Antonio, TX

Dr. Karen Kennedy
Veterinary Hospital
Greensboro, NC

Dr. Dan J. McIlhany
Towne North Animal
San Antonio, TX

Type of Study: Clinical trial in client-owned dogs.

Animals: One hundred thirty-four (134) of the 150 client-owned dogs enrolled completed the 12 month study. Sixty-six (66) of the dogs that completed the study were in the low dose treatment group and sixty-eight (68) were in the positive control group.

Dosage Form: SAFEHEARTä Tablets

Route of Administration: Oral

Dose Tested: Minimum dose of 0.1 mg/kg

Frequency of Treatment: Monthly for 12 months. All dogs were tested for D. immitis microfilaria and antigen at months 5 and 12.

Control: Interceptorâ (milbemycin oxime) Flavor Tabs (minimum dose of 0.5 mg/kg)

NADA 140-915

Duration of Study: Twelve months

Results: All dogs from both treatment groups were negative for D. immitis microfilaria and adult antigen at months 5 and 12.

Conclusions: The low dose of milbemycin oxime (0.1 mg/kg) provides effective heartworm prevention in the dog.

Adverse Reactions: The following clinical observations were noted during the study


Number of Enrolled Dogs

Observations Safeheartä (n = 75) Interceptorâ (n = 75)
Anorexia/¯ appetite 4 0
Vomiting 3 3
Diarrhea 3 1
Lethargy 2 1


Target animal safety studies in support of this supplement are referenced in the FOI Summary for the original NADA 140-915 approval.


Data on human safety, pertaining to consumption of drug residues in food were not required for approval of this supplemental NADA. This drug is to be labeled for use in dogs which are non-food animals. 


The data in support of this supplement comply with the requirements of Section 512 of the Act and Part 514 of the implementing regulations. The data demonstrate that SAFEHEARTä (milbemycin oxime) Tablets, when used under labeled conditions of use, are safe and effective.

According to the Center’s supplemental approval policy (21 CFR 514.106) this is a Category II change. This supplement provides for a change in dose for dogs from a minimum of 0.5 mg/kg to a minimum of 0.1 mg/kg with a corresponding restriction in indications to the prevention of heartworm disease only.

The drug is restricted to use by or on the order of a licensed veterinarian because professional expertise is judged to be critical for the diagnosis of heartworms and for the safe use of the product.

Under section 512(c)(2)(F)(iii) of the FFDCA, this approval for non food producing animals qualifies for THREE years of marketing exclusivity beginning on the date of approval because the supplemental application contains substantial evidence of the effectiveness of the drug involved, or any studies of animal safety, required for the approval of the application and conducted or sponsored by the applicant. The three years of marketing exclusivity applies only to the new dose and restricted indication for which the supplemental application was approved.

Patent # 4,547,520 expires on June 14, 2004


  1. Veterinary Insert
  2. Client Insert
  3. Blister Pack
  4. Tablet Carton
  5. Display Carton
  6. Shipper Carton

Copies of applicable labels may be obtained by writing to the:

Freedom of Information Office
Center for Veterinary Medicine, FDA
7500 Standish Place
Rockville, MD 20855

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