Praziquantel

About Praziquantel

Praziquantel is an anthelmintic, a medicine that kills parasitic worms. The current label approves it for patients 1 year and older with schistosomiasis caused by any Schistosoma species, and for clonorchiasis and opisthorchiasis (liver fluke infections). The dose is based on body weight: for schistosomiasis, 20 mg/kg three times in one day, and for the liver flukes, 25 mg/kg three times in one day, with the doses 4 to 6 hours apart.

There is no boxed warning. Praziquantel must not be used by anyone allergic to it, in ocular cysticercosis (a tapeworm cyst in the eye), because killing the parasite there can cause irreversible eye damage, or together with strong CYP3A inducers such as rifampin. Symptoms can get worse during treatment, sometimes dangerously, mainly when schistosomiasis is treated in its early acute phase. It can worsen nervous system disease, so people with epilepsy are treated with care, and anyone with cysticercosis of the brain is treated in the hospital. Irregular heart rhythms have been seen, and moderate or severe liver disease raises blood levels. Common side effects are feeling unwell, fever, headache, dizziness, stomach discomfort with or without nausea, and hives; they can be stronger in people with a heavy worm burden.

It can cause drowsiness, so do not drive or operate machinery on the day of treatment or the next day. The 600 mg tablet has three score lines and breaks into four 150 mg segments, which is how weight-based doses are measured out. Published studies in pregnancy have not linked it to birth defects or miscarriage, and small amounts pass into breast milk, so the prescriber weighs breastfeeding against the need for treatment. Bayer discontinued Biltricide in 2024, and in 2026 the FDA determined that it was not withdrawn for reasons of safety or effectiveness.

Taking Praziquantel

How to take it

Take each dose with water during a meal. Swallow tablets or segments whole without chewing or holding them in your mouth, because the bitter taste can cause gagging or vomiting; for children under 6, the label allows crushing the dose into semi-solid food or liquid and taking it within 1 hour.

If you miss a dose

Since the course is one day, ask the prescriber what to do if a dose is missed.

Storage

Store at room temperature, 68 to 77 degrees F (20 to 25 degrees C), tightly closed and out of reach of children. Do not flush unused tablets; use a take-back program.

Interactions to know about

Rifampin must not be taken with praziquantel, and efavirenz is avoided; when treatment can wait, these are stopped at least 2 to 4 weeks before and restarted one day after treatment ends. Cimetidine, ketoconazole, itraconazole, erythromycin, ritonavir and grapefruit juice can raise praziquantel levels, so tell the pharmacist about every medicine and supplement you take.

This summarizes the official prescribing information. Your prescriber’s and pharmacist’s instructions, and the leaflet that comes with your medicine, take priority.

Why the cash price for Praziquantel differs from pharmacy to pharmacy

Praziquantel is prescribed rarely in the US, so many pharmacies do not keep it on the shelf and order it in when a prescription arrives. A pharmacy that has to order it may quote differently than one that already stocks it.

Because the dose depends on body weight, the number of tablets on a prescription varies from person to person, and the tablets come in bottles of 6; compare quotes for the same tablet count. The dispensing fee is part of every quote.

Ways to pay less for Praziquantel without insurance

• Ask the prescriber to write the generic name, praziquantel 600 mg tablets, since the Biltricide brand is no longer sold.
• Before sending the prescription, ask the pharmacy whether it has praziquantel in stock or how long ordering it will take, since treatment is usually planned for a specific day.
• Compare quotes from more than one pharmacy for the same number of tablets.
• Never buy praziquantel from an online seller that does not require a prescription.
• Upload the prescription to Script Unlock so licensed pharmacies can quote their cash price. You pay the pharmacy directly.

Questions to ask your pharmacist about Praziquantel

1. 1.How many tablets or tablet segments do I take for each of my three doses, and how do I break them along the score lines?
2. 2.Do any of my medicines, such as rifampin or efavirenz, interact with my praziquantel?
3. 3.Can my child’s dose be crushed and mixed with food, and how soon must it be taken?
4. 4.Which reactions after my treatment mean I should call my doctor or get help right away?

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