Fenbendazole

Uses and Indications

This drug is indicated for the treatment and control of various parasitic infections in multiple species.

Canine Indications

• Fenbendazole and Panacur C Canine are indicated for the treatment and control of:

  • Roundworms: Toxocara canis, Toxascaris leonina

  • Hookworms: Ancylostoma caninum, Uncinaria stenocephala

  • Whipworms: Trichuris vulpis

  • Tapeworms: Taenia pisiformis

Feline Indications

• Panacur is indicated for the control of:

  • Ascarids: Toxocara cati, Toxascaris leonina, Baylisascaris transfuga

  • Hookworms: Ancylostoma spp., Ancylostoma caninum

  • Tapeworms: Taenia hydatigena, T. krabbei, T. taeniaeformis

Equine Indications

• Safe-Guard and Panacur are indicated for the treatment and control of:

  • Large strongyles: Strongylus edentatus, S. equinus, S. vulgaris

  • Encysted early 3rd stage (hypobiotic), late 3rd stage and 4th stage cyathostome larvae

  • Small strongyles: Cyathostomum spp., Cylicocyclus spp., Cylicostephanus spp., Cylicodontophorus spp.

  • Pinworms: Oxyuris equi

  • Ascarids: Parascaris equorum

  • Control of arteritis caused by 4th stage larvae of Strongylus vulgaris

Bovine Indications

• Safe-Guard, Panacur, and Defendazole are indicated for the treatment and control of:

  • Lungworms: Adult Dictyocaulus viviparus

  • Stomach worms:

    • Adult brown stomach worms: Ostertagia ostertagi

    • Adult and fourth stage larvae barberpole worms: Haemonchus contortus, H. placei

    • Adult and fourth stage larvae small stomach worms: Trichostrongylus axei

  • Intestinal worms (Adult and fourth stage larvae):

    • Hookworms: Bunostomum phlebotomum

    • Thread-necked intestinal worms: Nematodirus helvetianus

    • Small intestinal worms: Cooperia punctata, C. oncophora

    • Bankrupt worms: Trichostrongylus colubriformis

    • Nodular worms: Oesophagostomum radiatum

Caprine Indications

• Safe-Guard and Defendazole are indicated for the treatment and control of stomach worms (adults):

  • Haemonchus contortus

  • Teladorsagia circumcincta

Avian Indications

• Safe-Guard Aquasol is indicated for the treatment and control of:

  • Adult Ascaridia galli in broiler chickens and replacement chickens

  • Adult A. galli and Heterakis gallinarum in breeding chickens and laying hens

Swine Indications

• Safe-Guard Aquasol is indicated for the treatment and control of:

  • Lungworms: Adult Metastrongylus apri, Metastrongylus pudendotectus

  • Gastrointestinal worms:

    • Large roundworms: Ascaris suum

    • Nodular worms: Oesophagostomum dentatum, O. quadrispinulatum

    • Small stomach worms: Hyostrongylus rubidus

    • Whipworms: Trichuris suis

Usage Instructions

• For pets, it is advised to weigh the animal to ensure the correct dosage is used. Daily doses based on pet weight should be followed as specified in the product guidelines.

• For cattle, the dosage is typically 2.3 mg/lb (5 mg/kg) body weight, with specific instructions for beef cattle at 4.6 mg/lb (10 mg/kg) for certain conditions.

• For horses, the dosage is also 2.3 mg/lb (5 mg/kg) for various conditions, with specific instructions for treatment of ascarids at 4.6 mg/lb (10 mg/kg).

Limitations of Use

• Consult a veterinarian for assistance in the diagnosis, treatment, and control of parasitism, especially in cases of sick animals.

Dosage and Administration

Fenbendazole is available in various forms, including powder, paste, granule, and suspension, with packaging options ranging from 1 kg to 25 kg. The specific route, method, and frequency of administration may vary based on the formulation and species being treated.

For horses, Safe-Guard® Paste 10% is administered orally at a dosage of 2.3 mg/lb (5 mg/kg) for the control of large strongyles, small strongyles, and pinworms. For foals and weanlings under 18 months, a higher dose of 4.6 mg/lb (10 mg/kg) is recommended. For the control of hypobiotic (encysted early 3rd stage), late 3rd stage, and 4th stage cyathostome larvae, as well as 4th stage Strongylus vulgaris larvae, the recommended dosage is 4.6 mg/lb (10 mg/kg) daily for 5 consecutive days.

In beef and dairy cattle, Safe-Guard® Paste 10% and Safe-Guard® Suspension are administered orally at a rate of 2.3 mg/lb (5 mg/kg), equivalent to 11.5 g for a 500 lb (227 kg) animal. For specific conditions such as Type II Ostertagiasis or tapeworms, a higher dosage of 4.6 mg/lb (10 mg/kg) may be required.

For canine patients, Panacur® C Granules and Safe-Guard® Canine Granules are dosed at 50 mg/kg (22.7 mg/lb) of body weight for 3 consecutive days. The dosing should be mixed with a small amount of the usual food to ensure complete consumption. The specific granule amounts vary by weight, with detailed dosing tables provided for accurate administration.

For felids and ursids, the dosage is 10 mg/kg (4.54 mg/lb) daily for 3 consecutive days, with the granules measured accordingly.

Safe-Guard® AquaSol is administered orally to chickens via drinking water at a daily dose of 1 mg/kg body weight (0.454 mg/lb) for 5 consecutive days. The medicated water must be prepared fresh daily.

All formulations require careful adherence to dosing guidelines based on current body weight to avoid underdosing, which may lead to ineffective treatment and the development of parasite resistance.

Contraindications

Use is contraindicated in the following situations:

• Deworming is not recommended for dogs or puppies that are sick; veterinary consultation is advised for diagnosis of the illness.

• The product should not be used in dairy cattle at a dosage of 10 mg/kg.

• It is contraindicated for use in horses intended for human consumption.

• Not for use in beef calves less than 2 months of age, dairy calves, and veal calves.

• Use is prohibited in lactating goats due to the lack of established milk discard time.

• Milk from treated cows must not be used for human consumption during treatment and for 48 hours after the last treatment.

• Cattle must not be slaughtered for human consumption within 8 days following the last treatment.

• Goats must not be slaughtered for human consumption within 6 days following the last treatment.

Warnings and Precautions

NOT FOR USE IN HUMANS All formulations of the products listed are not intended for human use.

Keep Out of Reach of Children It is imperative to keep this and all medications out of the reach of children to prevent accidental ingestion.

Occupational Safety Information The Safety Data Sheet (SDS) contains detailed occupational safety information. For customer service, adverse effects reporting, or to obtain a copy of the SDS, contact 1-800-211-3573. For additional information regarding adverse drug experience reporting for animal drugs, contact the FDA at 1-888-FDAVETS or visit http://www.fda.gov/reportanimalaehttp://www.fda.gov/reportanimalae.

Parasite Resistance Parasite resistance may develop to any dewormer, and has been reported for most classes of dewormers. Treatment with a dewormer, in conjunction with appropriate parasite management practices, may slow the development of resistance. Regular monitoring of treatment effectiveness is essential, and adjustments to the parasite management plan should be made based on this monitoring.

Monitoring Treatment Effectiveness Following the use of any dewormer, the effectiveness of treatment should be monitored, for example, through fecal egg count reduction tests. A decrease in effectiveness over time may indicate the development of resistance to the dewormer administered.

Withdrawal Periods and Residue Warnings For certain products, milk taken during treatment and for 60 hours after the last treatment must not be used for human consumption. Cattle must not be slaughtered for human consumption within 13 days following the last treatment with these products. Specific withdrawal periods have not been established for pre-ruminating calves.

Consultation with Veterinarian Consultation with a veterinarian is recommended for the diagnosis of illness prior to deworming, especially in sick dogs or puppies.

Side Effects

In clinical studies involving Panacur and Safe-Guard products, adverse reactions were primarily limited to gastrointestinal disturbances. Specifically, in U.S. clinical studies, approximately 1% of treated dogs (3 out of 240) experienced vomiting, which may have been drug-related.

Serious Adverse Reactions

• No serious adverse reactions have been reported for fenbendazole products in the available data.

Common Adverse Reactions

• No common adverse reactions have been identified across the various formulations of fenbendazole.

Allergic Reactions

• Allergic reactions have not been specifically documented; however, hypersensitivity reactions may occur, particularly at higher doses due to the release of antigens from dying parasites. Symptoms can range from localized itching or rash to more severe systemic reactions, including increased respiration and collapse.

Precautions and Warnings

• All fenbendazole products carry a warning against use in humans and advise keeping the medication out of reach of children.

• Side effects associated with Safe-Guard® Paste and Panacur® Paste could not be established in well-controlled safety studies in horses, even at high doses.

• The potential for parasite resistance to develop with any dewormer is acknowledged, necessitating regular monitoring of treatment effectiveness.

Postmarketing Experience

• No postmarketing adverse reactions have been reported in the available data.

Additional Notes

• Another benzimidazole has been associated with hepatotoxicity in canines; however, this effect has not been reported with fenbendazole during clinical use.

Overall, the data suggest that fenbendazole is generally well-tolerated, with minimal adverse reactions reported in clinical settings.

Drug Interactions

There is no documented information regarding drug interactions for Fenbendazole, Panacur, or Defendazole. Additionally, there are no known interactions with laboratory tests for these medications. As such, healthcare professionals should be aware that the absence of interaction data does not imply safety or efficacy in combination with other drugs or tests. Monitoring and clinical judgment are advised when considering the use of these products in conjunction with other therapies.

Pediatric Use

Pediatric use of fenbendazole has not been established, and safety and effectiveness in pediatric patients have not been determined. It is advised to consult a veterinarian for appropriate dosing and safety considerations in children.

For Panacur and Defendazole, these products are not indicated for use in beef calves less than 2 months of age, dairy calves, and veal calves. Additionally, a withdrawal period has not been established for these products in pre-ruminating calves. Consultation with a veterinarian is recommended for assistance in the diagnosis, treatment, and control of parasitism.

Geriatric Use

No specific information regarding geriatric use, dosage adjustments, safety concerns, or special precautions for elderly patients is provided in the inserts for Fenbendazole, Panacur, and Defendazole. Therefore, healthcare professionals should exercise caution and consider individual patient factors when prescribing these medications to geriatric patients. Regular monitoring may be warranted to ensure safety and efficacy in this population.

Pregnancy

There is currently no specific information available regarding the use of fenbendazole, Panacur, or Defendazole during pregnancy. The provided data does not detail any safety concerns, dosage modifications, or special precautions for pregnant patients. As such, healthcare professionals are advised to exercise caution and consider the lack of data when prescribing these medications to pregnant patients. Further research may be necessary to fully understand the implications of these treatments on fetal outcomes.

Lactation

There is limited information available regarding the use of Fenbendazole in lactating mothers, as the drug insert does not provide specific data on this topic.

For products such as Panacur and Defendazole, it is important to note that milk from treated cows should not be used for human consumption during treatment and for 48 hours following the last dose. Additionally, there is no established withdrawal period for pre-ruminating calves, and lactating goats should not be treated with Defendazole due to the lack of a defined milk discard time.

Healthcare professionals should exercise caution and consider these factors when advising lactating mothers or when treating animals that produce milk intended for human consumption.

Renal Impairment

Patients with renal impairment may require careful consideration when using certain medications. Specifically, for Panacur C Canine, it is advised that dosage adjustments may be necessary for individuals with reduced kidney function. Additionally, monitoring of renal function tests is recommended for these patients, and a reduced dose should be considered for those with decreased creatinine clearance.

For other products such as Fenbendazole, Safe-Guard (in various forms), and Panacur (in multiple formulations), there is no specific information provided regarding renal impairment, dosage adjustments, or special monitoring requirements. Therefore, healthcare professionals should exercise caution and consider individual patient circumstances when prescribing these medications to patients with kidney problems.

Hepatic Impairment

Patients with hepatic impairment have no specific information regarding dosage adjustments, special monitoring, or precautions for the following medications: Fenbendazole (powder), Safe-Guard (paste, powder, suspension), Panacur (suspension, granule, paste), and Defendazole (suspension). The drug inserts for these products do not provide guidance on the use of these medications in individuals with liver problems. Therefore, healthcare providers should exercise caution and consider the lack of data when prescribing these medications to patients with hepatic impairment.

Overdosage

In the event of an overdose, specific information regarding symptoms and management is not provided for any of the products listed, including Fenbendazole, Safe-Guard, Safe-Guard Aquasol, Panacur C Canine, and Defendazole.

Given the absence of detailed overdosage information across all formulations, it is recommended that individuals monitor for any unusual symptoms or adverse effects following administration. In case of suspected overdose, it is advisable to contact a veterinarian or poison control center for guidance on appropriate interventions.

For products such as Panacur, which explicitly states "NOT FOR USE IN HUMANS," it is crucial to keep all medications out of reach of children. In the event of accidental ingestion or exposure, immediate medical attention should be sought.

For further assistance, including adverse effects reporting or obtaining a Safety Data Sheet (SDS), individuals should contact customer service at 1-800-211-3573 or reach out to the FDA at 1-888-FDAVETS for additional information regarding adverse drug experiences in animals.

Nonclinical Toxicology

Teratogenicity

No information is available regarding teratogenic effects for Fenbendazole, Panacur, or Defendazole.

Carcinogenesis, Mutagenesis, Impairment of Fertility

There is no information provided concerning carcinogenicity, mutagenicity, or impairment of fertility for any of the products.

Animal Toxicology

Panacur has been administered to pregnant and non-pregnant females, as well as male animals, including Felidae and Ursidae, at doses up to ten times the recommended level for twice the recommended treatment duration without any observed effects on reproduction. However, in one instance involving a puma and a jaguar, administration of ten times the recommended dose for the same duration resulted in evidence of inappetence. No additional information is available regarding animal pharmacology and toxicology for Fenbendazole or Defendazole.

Storage and Handling

Fenbendazole is supplied as a powder. It should be stored in a cool, dry place, protected from light, and the container must be kept tightly closed when not in use. Freezing is not permitted, and any unused portion should be discarded after opening.

Safe-Guard is available in multiple forms: paste, powder, and suspension. The paste and powder forms should be stored at or below 25°C (77°F), with excursions permitted up to 40°C (104°F). The suspension forms must also be stored at or below 25°C (77°F) and protected from freezing. It is important to shake the suspension well before use.

Safe-Guard Aquasol is provided as a suspension in a 3 mL glass vial. It should be stored at room temperature, specifically at 30°C (86°F), and must not be frozen. The product should be used within 6 months after opening, and the medicated water should be used within 24 hours.

Panacur is available in granule, paste, and suspension forms. The granule forms should be stored at a controlled room temperature of 68-77°F (20-25°C). The paste and suspension forms must be stored at or below 25°C (77°F) and protected from freezing. The suspension forms require shaking well before use.

Defendazole is supplied as a suspension and should be stored at temperatures between 59°F (15°C) and 86°F (30°C). While excursions up to 104°F (40°C) are permitted, such exposure should be minimized. Brief exposure to temperatures down to 36°F (2°C) may be tolerated, but freezing must be avoided. The suspension should be shaken well before use.