Epsiprantel
Pyrazino-benzazepine
Also known as: Cestex · BRL-38705
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Dosing by species
🌎 NA — North America🌍 EU — Europe
Dogs
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Cestode infection (Dipylidium caninum, Taenia pisiformis) | 5.5 mg/kg (2.5 mg/lb) | PO | once | Single dose | 🌎 NA |
- Cestode infection (Dipylidium caninum, Taenia pisiformis): Round up to the next larger tablet size
Cats
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Cestode infection (Dipylidium caninum, Taenia taeniaeformis) | 2.75 mg/kg | PO | once | Single dose | 🌎 NA |
- Cestode infection (Dipylidium caninum, Taenia taeniaeformis): Cats up to 10 lb should receive one 12.5 mg tablet; cats 11-20 lb should receive one 25 mg tablet
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Epsiprantel is an oral cestocidal antiparasitic agent used primarily for the treatment of tapeworm infections in dogs and cats.
- Indications: Highly effective for the removal of Dipylidium caninum and Taenia pisiformis in dogs, and Dipylidium caninum and Taenia taeniaeformis in cats.
- Clinical Pearl: Unlike praziquantel, epsiprantel is very poorly absorbed from the gastrointestinal tract. This lack of systemic absorption contributes to its exceptionally wide safety margin and minimal risk of systemic adverse effects.
Mechanism of action
While the exact mechanism of action against cestodes is not fully elucidated, epsiprantel acts directly on the tapeworm:
- Calcium Dysregulation → Induces severe tetany (muscle spasms) in the parasite.
- Attachment Disruption → Causes the tapeworm to lose its grip on the host's intestinal mucosa.
- Integument Alteration → Damages the worm's outer protective layer, rendering it highly vulnerable to digestion by the host animal's gastrointestinal enzymes.
Safety & warnings
Contraindications
- Puppies less than 7 weeks of age
- Kittens less than 7 weeks of age
Adverse effects
- Vomiting (rare)
- Diarrhea (rare)
Precautions
Age Restriction: The manufacturer states not to use in puppies or kittens less than 7 weeks of age.
Safety for use in pregnant or breeding animals has not been definitively determined, though teratogenic effects are highly unlikely due to the drug's extremely poor systemic absorption.
Drug interactions
Theoretically may reduce the drug's efficacy by decreasing gastrointestinal transit time
Theoretically may reduce the drug's efficacy
Monitoring
- Clinical efficacy (resolution of tapeworm infection)
Pharmacokinetics
Absorption
Absorbed very poorly after oral administration.
Distribution
Remains primarily within the gastrointestinal tract.
Metabolism
No metabolites have thus far been detected.
Elimination
The bulk of the drug is eliminated unchanged in the feces. Less than 0.1% of the drug is recovered in the urine after dosing.
Overdose
Acute toxicity resulting from an inadvertent overdose is highly unlikely due to poor systemic absorption.
- Cats: Doses as high as 36X the recommended dose resulted in vomiting in some of the kittens tested.
- Dogs: Single doses of 36X those recommended in dogs caused no adverse effects.
Available products
Formulations
- Oral tablets
Veterinary
- Epsiprantel Oral Tablets (Film-coated): 12.5 mg, 25 mg, 50 mg & 100 mg; Cestex® (Pfizer)
Regulatory status
No regulatory data for: 🇺🇸 US · 🇪🇺 EU · 🇬🇧 UK · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Tablets should be stored at room temperature.
Client information
- No Fasting Required: Fasting is not required nor is it recommended before dosing. You can give this medication with or without food.
- Invisible Results: Because the medication damages the tapeworm and causes it to be partially or completely digested by your pet's body, you likely will not see dead worms or worm fragments in the stool after treatment.
- Prevent Reinfection: A single dose is usually effective. However, since the most common tapeworm (Dipylidium caninum) is transmitted by swallowing infected fleas, strict flea control is essential to prevent your pet from getting tapeworms again.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.