What is pyrantel pamoate?
Pyrantel pamoate (brand names Nemex®, Nemex 2®) is an anthelmintic (dewormer). It is used to treat intestinal roundworm, hookworm, and stomach worm parasites in many species, including dogs, cats, small mammals, and birds.
The use of pyrantel pamoate to treat intestinal parasites in cats is off label (extra label). This medication is also used off-label to treat roundworms and hookworms in small mammals such as rabbits and rodents, as well as birds.
Many drugs are commonly prescribed for off-label use in veterinary medicine. “Off label” means the drug is being used in a way that has not been reviewed or approved by the U.S. Food and Drug Administration (FDA) or Health Canada. In these instances, follow your veterinarian’s directions and cautions carefully, as they may be significantly different from those on the label.
Pyrantel pamoate is also found in a variety of combination products for treating other intestinal parasites and/or heartworm.
How is pyrantel pamoate given?
- Pyrantel pamoate is given by mouth. It is available as a capsule, chewable tablet, and liquid suspension.
- Pyrantel pamoate can be given with or without food. If vomiting occurs after receiving a dose on an empty stomach, give future doses with food.
- Shake liquid forms well before use.
- Measure the dosage carefully. Follow the dosing instructions provided by your veterinarian.
This medication should take effect within one to two hours; however, effects may not be noted outwardly, so laboratory tests may be needed to evaluate this medication’s effectiveness.
What if I miss giving my pet the medication?
If you miss a dose, give it as soon as you remember, and then wait the recommended time for the next dose, as prescribed by your veterinarian. Do not give the pet two doses at once. It is critical to give the medication for the full length of time your veterinarian recommends.
Are there any potential side effects?
Side effects of pyrantel pamoate are rare when dosed appropriately, but may include:
- Nausea
- Vomiting
- Lack of appetite
- Diarrhea
Contact your veterinarian if these signs become severe or continue to be a problem.
Other side effects may occur. If you notice anything unusual, contact your veterinarian immediately. This short-acting medication should stop working within 24 hours, although effects can be longer in pets with liver or kidney disease.
Are there any risk factors for this medication?
DO NOT USE pyrantel pamoate in:
- Pets that are allergic to it
- Pets that are severely weakened or frail
USE WITH CAUTION in:
- Pregnant animals (follow the dosing instructions carefully)
Are there any drug interactions I should be aware of?
Several medications should be used with caution when given with pyrantel pamoate, including:
- Levamisole
- Morantel
- Piperazine
Exposure to organophosphates (pesticides) while taking pyrantel pamoate should be avoided. Be sure to tell your veterinarian about any medications (including vitamins, supplements or herbal therapies) that your pet is taking before starting any treatment.
Is any monitoring needed with this medication?
- Your veterinarian will let you know when and how they want to reassess your pet to ensure the medication is working and not causing side effects.
- At home, monitor for any side effects such as those noted above. If any occur, stop using the medication and contact your veterinarian.
How do I store pyrantel pamoate?
- Store pyrantel pamoate tablets in a tightly sealed container, protected from light, at room temperature (15°C–30°C or 59°F–86°F).
- Liquid suspensions should not be exposed to direct sunlight.
- Keep out of reach of children and pets. 
What should I do in case of an emergency?
Pyrantel pamoate can be toxic when given regularly over a period of months. If you suspect an overdose or an adverse reaction to the medication, call your veterinary office immediately. If they are not available, follow their directions in contacting an emergency facility. Be prepared to provide information about the product and your pet’s weight and symptoms.
