Pyrantel
Pyrantel is a tetrahydropyrimidine anthelmintic.
Group
Tetrahydropyrimidine anthelmintic
Mechanism of Action
Disrupts nematode cholinergic neuromuscular signaling and paralyzes intestinal worms.
Dose Rates
Dogs
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Intestinal nematodes | 5 mg/kg | PO | Once | Repeat after 7-10 days. |
| Intestinal nematodes in small dogs | 10 mg/kg | PO | Once | Pyrantel base; dogs below 5 lb. The original table does not define exactly 5 lb. |
| Puppy intestinal nematodes | 5–10 mg/kg | PO | Once | From 2-3 weeks of age; reported repeat every 2-3 weeks to at least 12 weeks. |
Cats
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Intestinal nematodes | 20 mg/kg | PO | Once | May mix with food. |
Horses
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Intestinal nematodes | 6.6 mg/kg | PO | Once | |
| Medicated-feed nematode treatment | 12.5 mg/kg | PO | Once | |
| Medicated-feed nematode prevention | 2.6 mg/kg | PO | Every 24 h | |
| Cestodes | 13.2 mg/kg | PO | Once | Pyrantel base by mouth; reported once or twice yearly in parasite-control plans. |
Pigs
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Intestinal nematodes | 22 mg/kg | PO | Once | Administer in feed. |
Indications
- Intestinal nematodes
- Equine tapeworm treatment at higher dose
- Intestinal nematodes in small dogs
- Puppy intestinal nematodes
- Cestodes
Interactions
- Potential increased CNS toxicity with levamisole.
Adverse effects
- Generally well tolerated at routine doses.
Toxicity
Marked exposure may produce tachypnea, sweating, ataxia and other cholinergic signs; toxic potential differs between pamoate and tartrate salts.
Preparations
| Preparation | Form | Strength | Route |
|---|---|---|---|
| Pyrantel suspension 2.27 mg base/mL | Oral Liquid | 2.27 mg / mL | PO |
| Pyrantel suspension 4.54 mg base/mL | Oral Liquid | 4.54 mg / mL | PO |
| Pyrantel suspension 50 mg base/mL | Oral Liquid | 50 mg / mL | PO |
| Pyrantel tablet 22.7 mg base | Tablet | 22.7 mg / tablet | PO |
| Pyrantel tablet 113.5 mg base | Tablet | 113.5 mg / tablet | PO |
Monitoring and Administration
Dose as pyrantel base. Shake suspensions and monitor fecal parasite response. Protect from freezing; parasite-control schedules may require repeat treatment.
Equine cestode amount is 13.2 mg/kg; the administration route is unspecified for this regimen and no route-specific calculator regimen is created.
Many pamoate amounts in the older reference do not identify salt versus base. Do not reassign those to the base calculator. Rabbit pinworm line reads 15-10 mg/kg, a reversed/ambiguous range. Pig tartrate 22 mg/kg single or 2.6 mg/kg/day for 3 days, ruminant tartrate 25 mg/kg, bird pamoate and feline combination amounts need their exact ingredient basis before normalization.