Emodepside / Praziquantel

Anthelmintic combination Cyclooctadepsipeptide (emodepside) and pyrazinoisoquinoline (praziquantel)

Dosage & Administration Guidelines

Species Route Dose Frequency Duration & Clinical Notes
Dog PO Emodepside 1 mg/kg + Praziquantel 5 mg/kg Single dose Duration: One administration; repeat as needed based on veterinary advice
Notes: Administer with food to enhance absorption. For Echinococcus, repeat after 2-4 weeks.
Cat PO Emodepside 1 mg/kg + Praziquantel 5 mg/kg Single dose Duration: One administration; repeat as needed based on veterinary advice
Notes: Administer with food. Safe for kittens over 8 weeks of age.

Clinical Indications & Species Uses

General Indications
  • Broad-spectrum deworming for companion animals
Dog (Canine)
  • Treatment of gastrointestinal nematodes (roundworms, hookworms, whipworms)
  • Treatment of tapeworm infections (Dipylidium caninum, Taenia spp., Echinococcus spp.)
Cat (Feline)
  • Treatment of gastrointestinal nematodes (roundworms, hookworms)
  • Treatment of tapeworm infections (Dipylidium caninum, Taenia taeniaeformis)

Pharmacology & Mechanism of Action

Drug Class: Anthelmintic combination | Pharmacological Group: Cyclooctadepsipeptide (emodepside) and pyrazinoisoquinoline (praziquantel)

Mechanism of Action: Emodepside is a semisynthetic derivative of the fungal metabolite PF1022A. It acts on the nervous system of nematodes by binding to a specific G-protein-coupled receptor (SER-2) and also affects the calcium-activated potassium channel (SLO-1), leading to paralysis and death of the parasite. Praziquantel is effective against cestodes and trematodes; it increases the permeability of the parasite's cell membrane to calcium ions, causing severe contraction and paralysis, followed by vacuolization and disintegration of the tegument, leading to parasite death.

Pharmacodynamics: The combination provides broad-spectrum activity against both nematodes (emodepside) and cestodes (praziquantel). Emodepside is particularly effective against gastrointestinal roundworms, including larval stages, while praziquantel is highly effective against tapeworms. The two drugs act synergistically to cover a wide range of intestinal parasites in companion animals.

⚡ Pharmacokinetics Summary

Absorption: After oral administration, both emodepside and praziquantel are rapidly absorbed from the gastrointestinal tract. Peak plasma concentrations are reached within 1-4 hours. Absorption is enhanced when administered with food.
Distribution: Both drugs are widely distributed throughout the body. Emodepside has a high volume of distribution, indicating extensive tissue penetration. Praziquantel is distributed into tissues and body fluids, including cerebrospinal fluid. Both cross the blood-brain barrier to some extent.
Metabolism: Emodepside is extensively metabolized in the liver, primarily by cytochrome P450 enzymes, to multiple metabolites. Praziquantel undergoes extensive first-pass metabolism in the liver, forming both active and inactive metabolites. The main metabolite of praziquantel is the cis-isomer, which has some anthelmintic activity.
Excretion: Emodepside and its metabolites are excreted primarily in the feces via bile. Praziquantel and its metabolites are excreted mainly in the urine (up to 80%) and the remainder in feces. In lactating animals, small amounts may be excreted in milk.
Half-Life: Emodepside: approximately 1-2 days in dogs and cats. Praziquantel: approximately 1-3 hours in dogs and cats.
Bioavailability: Oral bioavailability is high for both drugs; emodepside is approximately 80-90%, and praziquantel is approximately 80% in dogs and cats.
Protein Binding: Emodepside: >99% bound to plasma proteins. Praziquantel: approximately 80-85% bound to plasma proteins.

Available Formulations & Strengths

Oral tablet Emodepside 12 mg + Praziquantel 60 mg (for small dogs/cats); Emodepside 24 mg + Praziquantel 120 mg (for medium dogs); Emodepside 48 mg + Praziquantel 240 mg (for large dogs) (PO)
Oral spot-on solution Emodepside 3 mg/ml + Praziquantel 12 mg/ml (for cats); Emodepside 20 mg/ml + Praziquantel 100 mg/ml (for dogs) (Topical)

Contraindications & Clinical Warnings

Contraindications:
  • Hypersensitivity to emodepside or praziquantel
  • Do not use in puppies or kittens under 8 weeks of age
  • Do not use in animals with known liver dysfunction (especially for praziquantel)
  • Do not use in pregnant or lactating animals unless specifically indicated by a veterinarian
Warnings & Clinical Precautions:
  • Use with caution in debilitated or geriatric animals
  • In cats, spot-on application should be applied to the skin at the base of the skull to prevent licking
  • Do not administer orally to animals with oral lesions or those that may bite the applicator
  • Keep out of reach of children and other animals
  • In dogs, do not use in Collies or other breeds with MDR1 mutation without veterinary guidance (emodepside is a substrate for P-glycoprotein)
  • For Echinococcus infections, strict hygiene measures should be taken to prevent human infection

Adverse Effects & Reactions

Common:

  • Transient salivation
  • Vomiting
  • Diarrhea
  • Lethargy

Serious / Severe:

  • Neurological signs (ataxia, tremors, seizures) – especially in overdose or in sensitive breeds
  • Hepatotoxicity (rare but possible with praziquantel)

Rare:

  • Allergic reactions (urticaria, facial swelling)
  • Anorexia

Key Drug Interactions

Interacting Drug / Class Clinical Effect & Mechanism Severity
P-glycoprotein inhibitors (e.g., ivermectin, ketoconazole, cyclosporine) May increase plasma levels of emodepside, increasing risk of toxicity High
Other anthelmintics (e.g., pyrantel, fenbendazole) Potential additive effects; generally safe but may increase risk of GI upset Moderate
Cimetidine May increase plasma levels of praziquantel by inhibiting its metabolism Moderate

Overdose & Toxicity Management

Signs of Toxicity:

  • Vomiting
  • Diarrhea
  • Ataxia
  • Tremors
  • Seizures
  • Depression
  • Respiratory distress

Emergency Treatment Protocol: There is no specific antidote. Treatment is symptomatic and supportive. Induce vomiting if recent ingestion and animal is conscious. Administer activated charcoal to reduce absorption. Provide IV fluids, anticonvulsants (e.g., diazepam) for seizures, and supportive care. Monitor hepatic and renal function.

Food Animal Withdrawal Times

Not approved for use in food-producing animals. Do not use in animals intended for human consumption.

Storage, Handling & Regulatory Information

Storage Temperature: Store at controlled room temperature 20-25°C (68-77°F), excursions permitted between 15-30°C (59-86°F)

Handling & Special Conditions: Store in a dry place, protect from moisture. Keep the container tightly closed.

Dispensing Status: Prescription Required (Rx Only)

Approval Status: Approved for use in dogs and cats in the US and Europe (e.g., Profender, Advocate).

Extra-Label (Off-Label) Use: In the US, extra-label use in food animals is prohibited. In companion animals, extra-label use may be permitted under AMDUCA with veterinary oversight, but safety and efficacy should be established.

Clinical Pearls & Practice Notes

💡 Clinical Insights: This combination is highly effective for routine deworming in dogs and cats, covering both roundworms and tapeworms. It is available as oral tablets and topical spot-on formulations. The spot-on formulation is convenient for cats and dogs that are difficult to medicate orally. Always confirm the correct dosage based on body weight. For Echinococcus infections, repeat treatment after 2-4 weeks to eliminate immature stages. In multi-pet households, treat all pets simultaneously to prevent reinfection. Advise clients on flea control to prevent Dipylidium infections. Monitor for adverse effects, especially in animals with a history of seizures or liver disease.

References & Literature

  • 📚 Plumb's Veterinary Drug Handbook
  • 📚 Papich Veterinary Pharmacology and Therapeutics
  • 📚 Compendium of Veterinary Products (CVP)