Panacur

Description

Panacur® (fenbendazole) Paste 10% is an anthelmintic formulation containing the active ingredient fenbendazole. The chemical name of fenbendazole is methyl 5-(phenylthio)-2-benzimidazole carbamate. Each gram of Panacur® Paste 10% contains 100 mg of fenbendazole. The paste is flavored with artificial apple-cinnamon liquid to enhance palatability.

Uses and Indications

This drug is indicated for the treatment and control of various parasitic infections in horses. Specifically, it is effective against large strongyles, including Strongylus edentatus, S. equinus, and S. vulgaris. Additionally, it targets encysted early 3rd stage (hypobiotic), late 3rd stage, and 4th stage cyathostome larvae, as well as small strongyles, pinworms (Oxyuris equi), and ascarids (Parascaris equorum). Furthermore, this drug is indicated for the control of arteritis caused by the 4th stage larvae of Strongylus vulgaris.

Healthcare professionals should ensure appropriate usage in accordance with the specified indications for optimal therapeutic outcomes.

Dosage and Administration

For foals and weanlings under 18 months of age, where ascarids are prevalent, the recommended dosage is 4.6 mg/lb (10 mg/kg). One syringe is sufficient to deworm a horse weighing 550 lb.

For the control of large strongyles, small strongyles, and pinworms, the recommended dosage is 2.3 mg/lb (5 mg/kg). One syringe will effectively deworm a horse weighing 1,100 lb.

In cases requiring 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) administered daily for 5 consecutive days. Each day, one syringe should be given for every 550 lb of body weight.

It is imperative to avoid underdosing. Each animal must receive a complete dose based on its current body weight to ensure effective treatment and to prevent the development of parasite resistance.

Contraindications

Use of this product is contraindicated in horses intended for human consumption. Additionally, it is not approved for use in humans.

Underdosing is also contraindicated; each animal must receive a complete dose based on current body weight to avoid ineffective treatment and the potential development of parasite resistance.

Warnings and Precautions

It is imperative to note that this product is not intended for use in humans. Strict adherence to this guideline is essential to ensure safety and efficacy.

To prevent accidental ingestion, the product must be kept out of reach of children. This precaution is critical to avoid potential harm.

For comprehensive occupational safety information, healthcare professionals are advised to consult the Safety Data Sheet (SDS). The SDS provides detailed insights into handling, storage, and emergency measures related to the product.

In the event of adverse effects or for customer service inquiries, healthcare professionals can reach out by calling 1-800-211-3573. This line is also available for obtaining a copy of the SDS.

For further information regarding the reporting of adverse drug experiences related to animal drugs, healthcare professionals should contact the FDA at 1-888-FDAVETS or visit the FDA website at http://www.fda.gov/reportanimalaehttp://www.fda.gov/reportanimalae. This resource is vital for ensuring the safety and well-being of animal patients.

Side Effects

Patients using Panacur® Paste 10% should be aware of the potential adverse reactions associated with its use. While specific side effects could not be established in well-controlled safety studies involving horses, it is important to note that the product is not intended for human use and should be kept out of reach of children.

In clinical evaluations, particularly at higher doses, the lethal action of fenbendazole may lead to the release of antigens from dying parasites. This can result in local or systemic hypersensitivity reactions. Such reactions should be managed symptomatically, as with any drug.

Panacur® Paste 10% has been assessed for safety in pregnant mares throughout all stages of gestation, with doses reaching up to 11.4 mg/lb (25 mg/kg), and in stallions at similar dosages. No adverse effects on reproduction were observed in these studies. However, the recommended dosage for controlling 4th stage Strongylus vulgaris larvae, which is 4.6 mg/lb (10 mg/kg) daily for five consecutive days, has not been evaluated for safety in stallions or pregnant mares. Therefore, caution is advised when considering this treatment in these populations.

Drug Interactions

There are no specific drug interactions associated with Panacur (fenbendazole) reported in the available data. Additionally, no laboratory test interactions have been identified for this medication. Therefore, no dosage adjustments or monitoring recommendations are necessary based on drug or laboratory test interactions.

Packaging & NDC

The table below lists each NDC Code for Panacur (fenbendazole) veterinary formulations. Columns show Packaging, Formulation Type, and Active Ingredient Strength.

Pediatric Use

For foals and weanlings (less than 18 months of age), where ascarids are a common concern, the recommended dosage is 4.6 mg/lb (10 mg/kg). One syringe is sufficient to deworm a horse weighing 550 lb, while a horse weighing 1,250 lb requires one syringe for effective treatment.

In the case of controlling 4th stage Strongylus vulgaris larvae, the recommended dosage is also 4.6 mg/lb (10 mg/kg) administered daily for 5 consecutive days. For this purpose, one syringe should be given for each 550 lb of body weight per day.

Additionally, 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 same dosage of 4.6 mg/lb (10 mg/kg) is recommended daily for 5 consecutive days, with one syringe for each 1,250 lb of body weight per day.

Geriatric Use

There is no specific information regarding the use of Panacur (fenbendazole) Paste 10% in geriatric patients, including dosage adjustments, safety concerns, or special precautions. Healthcare providers should exercise caution when prescribing this medication to elderly patients, as the absence of data necessitates careful consideration of individual patient factors and potential risks. Monitoring for any adverse effects or unusual responses in this population is advisable, given the lack of established guidelines for geriatric use.

Pregnancy

Panacur Paste 10% has been evaluated for safety in pregnant mares throughout all stages of gestation at doses up to 11.4 mg/lb (25 mg/kg), as well as in stallions at the same dosage. No adverse effects on reproduction were detected in these studies. However, the recommended dose for the control of 4th stage Strongylus vulgaris larvae, which is 4.6 mg/lb (10 mg/kg) daily for 5 consecutive days, has not been evaluated for safety in stallions or pregnant mares. Therefore, caution is advised when considering the use of this medication in pregnant patients or in stallions, as the safety profile at the recommended dosing regimen remains undetermined.

Lactation

There is no specific information available regarding the use of this medication in nursing mothers or any considerations related to lactation. Healthcare professionals should exercise caution and consider the potential risks and benefits when prescribing this medication to lactating mothers. The effects on breastfed infants have not been established, and further research may be necessary to determine the safety profile in this population.

Renal Impairment

There is no specific information available regarding dosage adjustments, special monitoring, or safety considerations for patients with renal impairment. Healthcare professionals should exercise caution when prescribing to patients with reduced kidney function, as the absence of detailed guidance necessitates careful clinical judgment. Regular monitoring of renal function may be advisable in these patients to ensure safety and efficacy.

Hepatic Impairment

Patients with hepatic impairment have not been specifically studied in relation to the use of this medication. Consequently, there are no established dosage adjustments, special monitoring requirements, or precautions outlined for individuals with compromised liver function. It is recommended that healthcare providers exercise caution when prescribing this medication to patients with hepatic impairment, given the lack of data on its safety and efficacy in this population. Regular monitoring of liver function may be prudent in these cases, although specific parameters are not defined in the available information.

Overdosage

Overdosage of this product is not intended for human use and should be strictly avoided. It is imperative to keep this product out of reach of children to prevent accidental ingestion or exposure.

In the event of an overdosage, healthcare professionals are advised to consult the Safety Data Sheet (SDS) for comprehensive occupational safety information. The SDS provides critical details that may assist in managing exposure and mitigating risks associated with overdosage.

For customer service inquiries, including reporting adverse effects or obtaining a copy of the SDS, healthcare professionals can contact the dedicated support line at 1-800-211-3573.

In cases involving animal drugs, additional information regarding adverse drug experience reporting can be obtained by contacting the FDA at 1-888-FDAVETS or visiting their website at http://www.fda.gov/reportanimalaehttp://www.fda.gov/reportanimalae. It is essential to follow these guidelines to ensure proper management and reporting of any adverse effects related to overdosage.

Nonclinical Toxicology

No adverse effects on reproduction were detected in pregnant mares during all stages of gestation at doses as high as 11.4 mg/lb (25 mg/kg). Similarly, stallions exhibited no adverse reproductive effects at the same dosage levels.

In well-controlled safety studies involving horses, side effects associated with Panacur Paste 10% could not be established, even with single doses as high as 454 mg/lb (1,000 mg/kg) and 15 consecutive daily doses of 22.7 mg/lb (50 mg/kg). It is noteworthy that at higher doses, the lethal action of fenbendazole may lead to the release of antigens from dying parasites, which could potentially result in local or systemic hypersensitivity reactions.

The recommended dose for the control of 4th stage Strongylus vulgaris larvae is 4.6 mg/lb (10 mg/kg) daily for 5 consecutive days; however, this dosage has not been evaluated for safety in stallions or pregnant mares.

Postmarketing Experience

Postmarketing experience with Panacur Paste 10% has revealed several important observations. Side effects associated with the product could not be established in well-controlled safety studies in horses, even at single doses as high as 454 mg/lb (1,000 mg/kg) and with 15 consecutive daily doses of 22.7 mg/lb (50 mg/kg). However, it is noted that the lethal action of fenbendazole, particularly at higher doses, may lead to the release of antigens from dying parasites, potentially resulting in local or systemic hypersensitivity reactions. Such reactions should be managed symptomatically.

The safety of Panacur Paste 10% has been evaluated in pregnant mares throughout all stages of gestation and in stallions, with doses up to 11.4 mg/lb (25 mg/kg) administered without detecting adverse effects on reproduction. It is important to note that the recommended dose for controlling 4th stage Strongylus vulgaris larvae, which is 4.6 mg/lb (10 mg/kg) daily for 5 consecutive days, has not been evaluated for safety in stallions or pregnant mares.

Additionally, reports indicate that parasite resistance may develop to any dewormer, including Panacur Paste 10%. This phenomenon has been documented across most classes of dewormers. To mitigate the development of resistance, it is advised that treatment with a dewormer be combined with appropriate parasite management practices tailored to the specific geographic area and the animals being treated. Following the administration of any dewormer, the effectiveness of the treatment should be monitored, for instance, through fecal egg count reduction tests. A decrease in effectiveness over time may suggest the emergence of resistance to the dewormer, necessitating adjustments to the parasite management plan based on regular monitoring.

For customer service inquiries, adverse effects reporting, or to obtain a copy of the Safety Data Sheet (SDS), individuals may contact 1-800-211-3573. For further information regarding adverse drug experience reporting for animal drugs, the FDA can be reached at 1-888-FDAVETS or through their website at http://www.fda.gov/reportanimalae.

Patient Counseling

Healthcare providers should advise patients that this product is not intended for use in humans and must be kept out of reach of children. It is essential to inform patients that a Safety Data Sheet (SDS) is available, which contains more detailed occupational safety information. For inquiries regarding customer service, reporting adverse effects, or obtaining a copy of the SDS, patients should be directed to call 1-800-211-3573.

Patients should be cautioned against using this product in horses intended for human consumption. It is important to discuss the potential for parasite resistance, which may develop with any dewormer, as it has been reported for most classes of dewormers. Providers should emphasize that treatment with a dewormer, when used alongside appropriate parasite management practices tailored to the geographic area and the specific animals being treated, may help slow the development of resistance.

Healthcare providers should recommend that fecal examinations or other diagnostic tests, along with a history of parasite management, be utilized to determine the appropriateness of the product for the herd prior to administering any dewormer. Following treatment, the effectiveness of the dewormer should be monitored, for instance, through a fecal egg count reduction test or another suitable method. A decrease in the drug's effectiveness over time, as indicated by these tests, may suggest the development of resistance to the administered dewormer.

Patients should be encouraged to adjust their parasite management plans based on regular monitoring results. Finally, it is crucial to advise patients to consult their veterinarian for assistance in the diagnosis, treatment, and control of parasitism.

Storage and Handling

The product is supplied in various package configurations, with specific NDC numbers available for identification. It is essential to store the product at or below 25°C (77°F) to maintain its integrity and efficacy. Proper storage conditions must be adhered to, ensuring that the product is kept in a suitable container that protects it from environmental factors. Special handling requirements should be observed to prevent any compromise to the product's quality.

Additional Clinical Information

No further data are available.

Drug Information (PDF)

This document includes the full labeling information for Panacur, as submitted by Merck Sharp & Dohme Corp. for veterinary use. It may include dosage by species, withdrawal periods, and administration instructions.

View veterinary label (PDF)