Usage
Fenbendazole is a broad-spectrum anthelmintic (antiparasitic) medication primarily used to treat and control various internal parasites in animals. While not FDA-approved for human use, it is sometimes prescribed off-label by veterinarians for certain parasitic infections in companion animals. It is effective against several gastrointestinal parasites, including:
- Roundworms ( Toxocara canis, Toxascaris leonina)
- Hookworms (Ancylostoma caninum, Uncinaria stenocephala)
- Whipworms (Trichuris vulpis)
- Certain Tapeworms (Taenia pisiformis)
- Giardia (Giardia intestinalis, a protozoan parasite)
- Lungworms
- Some Flukes
Alternate Names
How It Works
Pharmacodynamics: Fenbendazole disrupts the parasite’s metabolism by binding to tubulin, a protein essential for cell structure and function, including nutrient absorption. This binding inhibits the formation of microtubules, leading to energy depletion and ultimately the parasite’s death.
Pharmacokinetics:
- Absorption: Fenbendazole is poorly absorbed from the gastrointestinal tract, which is advantageous for treating intestinal parasites. Absorption is increased when administered with food.
- Metabolism: Fenbendazole is primarily metabolized in the liver to its sulfoxide metabolite, oxfendazole (also an active anthelmintic).
- Elimination: Fenbendazole and its metabolites are primarily excreted in the feces, with a small amount eliminated in urine.
Dosage
Fenbendazole dosing is typically based on body weight and the specific parasite being treated. The duration of treatment varies depending on the parasite and may range from a single dose to several consecutive days.
Standard Dosage
Note: The following information pertains primarily to veterinary use in animals. Human dosing should only be under the strict guidance of a medical professional and may vary considerably. Always consult with a veterinarian for appropriate animal dosing.
Adults (Animals):
- For most gastrointestinal parasites: 50 mg/kg body weight per day, orally, for 3 consecutive days.
Children (Animals):
- Puppies and kittens under 6 months: 50 mg/kg body weight per day, orally, for 3 consecutive days.
Special Cases (Animals):
- Pregnant animals: Fenbendazole is generally considered safe for use during pregnancy, especially for preventing transplacental and transmammary transmission of parasites. Specific protocols exist for deworming pregnant dogs and other animals; consult a veterinarian for guidance.
- Other species: Dosing may differ for other animal species; consult a veterinarian for species-specific recommendations.
Clinical Use Cases
The provided sources do not contain sufficient information about the clinical use cases for Fenbendazole in humans in settings such as Intubation, Surgical Procedures, Mechanical Ventilation, Intensive Care Unit (ICU) Use, or Emergency Situations.
Dosage Adjustments
Dosages may need adjustments based on the animal’s specific health condition, age, and concurrent medications. Always follow the veterinarian’s recommendations for dosing adjustments.
Side Effects
Common Side Effects (Animals):
- Mild gastrointestinal upset (vomiting, diarrhea)
- Increased salivation (drooling)
Rare but Serious Side Effects (Animals):
- Allergic reactions (facial swelling, hives, difficulty breathing)
- Bone marrow suppression (rare, more common in birds)
Contraindications (Animals):
- Hypersensitivity to fenbendazole or any of its components
- Use with caution in sick or debilitated animals
Drug Interactions (Animals):
No significant drug interactions are known in animals, but inform your veterinarian of all medications your patient is taking.
Pregnancy and Breastfeeding (Animals):
Fenbendazole is generally considered safe for use during pregnancy, particularly in the later stages, to prevent transmission of parasites to offspring. It’s also considered safe during lactation. However, always consult a veterinarian before administering any medication to pregnant or lactating animals.
Drug Profile Summary (Animals):
- Mechanism of Action: Binds to tubulin, disrupting parasite metabolism and leading to death.
- Side Effects: Generally mild; may include gastrointestinal upset.
- Contraindications: Hypersensitivity.
- Drug Interactions: No significant interactions known.
- Pregnancy & Breastfeeding: Generally safe, consult a veterinarian.
- Dosage: Varies by species and parasite; commonly 50 mg/kg/day for 3 days.
- Monitoring Parameters: Fecal examinations to assess treatment efficacy.
Popular Combinations
The sources do not provide information regarding popular drug combinations with fenbendazole.
Precautions (Animals):
- Accurate weighing is crucial for correct dosing.
- Administer with food to enhance absorption.
- Monitor for adverse reactions, especially in pregnant animals.
FAQs (Frequently Asked Questions) (Animals):
Q1: What is the recommended dosage for Fenbendazole in dogs?
A: The standard dose for dogs is 50 mg/kg body weight per day, administered orally, for 3 consecutive days. Adjustments may be necessary for puppies, pregnant or lactating dogs, or those with underlying health conditions.
Q2: Can I give Fenbendazole to my pregnant dog?
A: Fenbendazole is often used in pregnant dogs, especially during the later stages of pregnancy, to prevent the transmission of certain parasites to the puppies. However, it is essential to consult a veterinarian for appropriate timing and dosing.
Q3: How does Fenbendazole work?
A: Fenbendazole interferes with the parasite’s ability to absorb nutrients, leading to its death. It works by binding to tubulin, a protein essential for the formation of microtubules within the parasite’s cells.
Q4: What are the potential side effects of Fenbendazole in cats?
A: Side effects are generally rare and mild, including vomiting, diarrhea, or increased salivation.
Q5: How often should I deworm my pet with Fenbendazole?
A: The frequency of deworming depends on your pet’s age, lifestyle, and risk factors. Consult your veterinarian for personalized recommendations.
Q6: Can Fenbendazole be used to treat Giardia?
A: Yes, Fenbendazole is effective against Giardia intestinalis, although a longer treatment duration may be necessary compared to other intestinal parasites.
Q7: What should I do if my pet vomits after receiving Fenbendazole?
A: Vomiting is a possible side effect. If vomiting is persistent or severe, contact your veterinarian. They might suggest administering the medication with food or adjusting the dose.
Q8: Are there any drug interactions I should be aware of when giving my pet Fenbendazole?
A: No significant drug interactions are known in veterinary medicine. However, it is crucial to inform your veterinarian about all other medications or supplements your pet is receiving.
Q9: Where can I purchase Fenbendazole for my pets?
A: Fenbendazole is available through a veterinarian’s prescription. Do not administer any medications to your pet without consulting a veterinarian first.
