Febantel: what the FDA reviewed for dog products
1 Freedom of Information summary from the FDA Center for Veterinary Medicine for products containing Febantel, as typed records: every value below is followed by the verbatim passage it was taken from. Species as stated by each summary: Dogs and Cats.
Products
- Rintal® Tabs Anthelmintic Tablets (NADA/ANADA 140-912)
Rintal® Tabs Anthelmintic Tablets NADA 140-912, Original approval, July 19, 1991; sponsor Elanco US Inc.; species: Dogs and Cats; foi_id 526; FDA PDF
Indication
Removal of nematode parasites: in dogs and puppies hookworms (Ancylostoma caninum, Uncinaria stenocephala), ascarids (Toxocara canis, Toxascaris leonina) and whipworms (Trichuris vulpis); in cats and kittens hookworms (Ancylostoma tubaeforme) and ascarids (Toxocara cati)
Dose regimen
10 mg febantel/kg body weight (dogs and cats); 15 mg febantel/kg (puppies and kittens less than 6 mo of age, on a full stomach), Oral, Daily, 3 consecutive days (tablets: 27.2 mg No. 6 and 163.3 mg No. 36)
Dogs and Cats 10 mg febantel/kg body weight given daily for 3 consecutive days. Puppies and Kittens less than 6 mo. of age 15 mg febantel/kg body weight given on a full stomach daily for 3 consecutive days.
Target-animal safety
dose multiples 1X (22 mg/kg, highest proposed daily dose), 3X (66 mg/kg), 5X (110 mg/kg); duration 9 consecutive days (3 times the proposed 3-day duration); animals 16 dogs (four per group).
M. Kohlenberg also conducted a general safety study in 16 dogs using the 163.3 mg tablet. Four dogs, Group I, served as nontreated controls. Four dogs, Group II, received 22 mg of febantel/kg of body weight (the highest proposed daily dosage rate) for 9 consecutive days (3 times the proposed duration of treatment).
| Finding | Quote |
|---|---|
| No clinically significant signs or body weight changes at 22 mg/kg (1X) or 66 mg/kg (3X) for 9 days | No clinically significant signs or body weight changes were observed in the Group I, II or III dogs. |
| At 110 mg/kg/day (5X for 3X duration), 2 of 4 dogs developed inappetence, depression, salivation, vomition and dehydration on days 7-8 and died on days 14 and 15 with hemorrhagic signs | The remaining 2 dogs receiving the 110 mg/kg daily treatments (Group IV) began showing clinical signs of inappetence, depression, salivation, vomition and dehydration on days 7 and 8 of treatment. These dogs expired on days 14 and 15 with additional hemorrhagic signs. |
| Conclusion: no adverse effects at 66 mg/kg/day for 9 days (3X dose for 3X duration) | No adverse effects were observed in dogs treated with this febantel formulation at a daily dose of 66 mg/kg for 9 consecutive days (3 times the proposed dose for 3 times the proposed duration of treatment). |
| Drug tolerance test (1 dog each): 275 mg/kg x 9 days caused slight weight loss, transient inappetence, vomition/diarrhea, decreased WBC and neutrophils; 550 mg/kg x 9 days caused marked weight loss, depression, dehydration, incoordination, elevated BUN and alkaline phosphatase, decreased WBC, neutrophils and platelets | The dog which received the daily 550 mg/kg treatments showed significant weight loss, loss of appetite, vomition/diarrhea, depression, dehydration and slight incoordination. |
| Contraindicated in pregnant animals: 3X dose for 6 days in early pregnancy increased abortion and fetal abnormalities (Vercom Paste NADA data) | Elevated treatments (6 consecutive days with 3 times the labeled dosage rate) with febantel to dogs and cats in early pregnancy induced an increased incidence of abortion and fetal abnormalities. |
Effectiveness
Well-controlled, blinded bioequivalence study in mature dogs (Dr. E. C. Greiner, University of Florida) per CVM anthelmintic and bioequivalence guidelines: Rintal Tabs 10 mg febantel/kg daily for 3 days vs Vercom Paste 10 mg/kg (positive control) vs placebo tablets; animals ranked by pre-treatment egg counts and block-randomized; necropsy worm counts 7 days after first treatment; n = 30 (3 groups of 10); primary endpoint: Percent reduction of intestinal nematode counts at necropsy vs placebo (worms collected, identified and counted 7 days after first treatment); result: Rintal Tabs 98.3% efficacy against Ancylostoma sp. (A. caninum + A. braziliense) and 99.7% against Trichuris vulpis, vs Vercom Paste 99.7% and 96.4%; concluded bioequivalent to Vercom Paste. Puppy study: 99.8-100% (hookworms), 98.9-100% (ascarids). Corroborative field trial (117 completed cases incl. 25 dogs, 23 puppies): 99.9-100% egg count reduction in dogs and puppies
The 30 dogs were shown by pretreatment worm egg counts to harbor infections of common intestinal nematodes and were assigned in groups of 10 to 3 different treatments.
Adverse reactions
| Term | Treated | Control | Quote |
|---|---|---|---|
| Side effects (dog bioequivalence study, 30 dogs) | No side effects occurred after treatment. | ||
| Drug-related side effects (clinical field trial, 126 evaluable cases) | No drug related side effects were observed. |
Extraction notes: Original NADA (1991) for dogs and cats; effectiveness rests on bioequivalence of the tablet to the approved Vercom Paste (NADA 133-953) rather than on a conventional field trial, so the effectiveness entry is the pivotal dog bioequivalence study (Table 3 rows flattened: nematode, No. infected/% efficacy for Rintal Tabs, Vercom Paste, placebo). TAS entry is the dog General Safety Evaluation (Table 6); a 3-dog drug tolerance test (275 and 550 mg/kg x 9 days) and cat studies (deaths at 66-110 mg/kg in cats with pre-existing liver/kidney disease; repeat study in healthy cats safe to 110 mg/kg x 9 days, basis of the liver/kidney warning) are summarized in findings/notes. Approval date is not printed in the extracted text.
Reproduce: foi_structured_search(query="Febantel") and foi_summary_get(foi_id=...) in dog-geroscience-mcp; dataset foi-summaries-dog (config structured).