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Praziquantel (By mouth)

Praziquantel (praz-i-KWON-tel)

Treats infections caused by parasites, including schistosomiasis (blood flukes) or clonorchiasis and opisthorchiasis (liver flukes).

Brand Name(s):


There may be other brand names for this medicine.

When This Medicine Should Not Be Used:

This medicine is not right for everyone. Do not use it if you had an allergic reaction to praziquantel, or if you have a tapeworm infection in your eye (ocular cysticercosis).

How to Use This Medicine:


  • Your doctor will tell you how much medicine to use. Do not use more than directed.
  • Most people need to wait at least 4 hours after taking one dose of this medicine before they take the next dose. Do not wait more than 6 hours between each dose of this medicine.
  • It is best to take this medicine with food or milk.
  • Swallow the tablet whole with water. Do not chew or keep the tablet or tablet pieces inside the mouth. This medicine is bitter and may cause gagging or vomiting. If your child cannot swallow the tablet, you may crush or dissolve and mix it with semi-solid food or liquid. Take the mixture within 1 hour of mixing.
  • Do not break the tablet unless your doctor tells you to. If you have been told to break your tablet, you can break off a part by pressing the notch with your thumbnails. If one-fourth of a tablet is required, break the tablet from the outer end.
  • Take all of the medicine in your prescription to clear up your infection, even if you feel better after the first few doses.
  • Missed dose: Take a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. Do not take extra medicine to make up for a missed dose.
  • Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light.

Drugs and Foods to Avoid:

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

  • Do not use rifampin for 4 weeks before starting this medicine. You may restart rifampin one day after the last dose of this medicine.
  • Some medicines can affect how praziquantel works. Tell your doctor if you are using any of the following:
    • Cimetidine, dexamethasone, erythromycin, itraconazole, ketoconazole
    • Medicine to treat seizures (including carbamazepine, phenobarbital, phenytoin)
  • Do not eat grapefruit or drink grapefruit juice while you are using this medicine.

Warnings While Using This Medicine:

  • Tell your doctor if you are pregnant or breastfeeding, or if you have kidney disease, liver disease, heart rhythm problems, or a history of epilepsy or seizures.
  • This medicine kills the worms and could cause unwanted effects (including serum sickness) as your body heals, especially during the early stages of schistosomiasis.
  • Tell your doctor if you have brain or nerve problems caused by worm cysts in the brain. Your doctor may want you to be treated in a hospital.
  • This medicine can cause heart rhythm problems.
  • This medicine may make you dizzy or drowsy. Do not drive or do anything else that could be dangerous during treatment with this medicine and for 24 hours after the last dose.
  • Call your doctor if your symptoms do not improve or if they get worse.
  • Your doctor will check your progress and the effects of this medicine at regular visits. Keep all appointments.
  • Keep all medicine out of the reach of children. Never share your medicine with anyone.

Possible Side Effects While Using This Medicine:

Call your doctor right away if you notice any of these side effects:

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
  • Blistering, peeling, red skin rash
  • Bloody diarrhea, stomach pain
  • Fast, slow, or uneven heartbeat
  • Fever, chills, cough, sore throat, body aches, headache, joint swelling, muscle pain or stiffness, sweating
  • Seizures
  • Trouble sleeping, unusual excitement, nervousness, restlessness, or irritability, seeing or hearing things that are not there

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088

Last Updated: 5/1/2020

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