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May is Hepatitis Awareness Month.



(pray zi KWON tel)

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Tablet, Oral:

Biltricide: 600 mg [scored]

Brand Names: U.S.

  • Biltricide

Pharmacologic Category

  • Anthelmintic


Increases the cell permeability to calcium in schistosomes, causing strong contractions and paralysis of worm musculature leading to detachment of suckers from the blood vessel walls and to dislodgment


Oral: 80%


CSF concentration is 14% to 20% of plasma concentration


Extensive first-pass effect; metabolized by the liver to hydroxylated and conjugated metabolites


Urine ~80% (>99% as metabolites)

Time to Peak

Serum: 1-3 hours

Half-Life Elimination

Parent drug: 0.8-1.5 hours; Metabolites: 4.5 hours

Protein Binding


Special Populations: Renal Function Impairment

Excretion may be delayed in patients with renal impairment, but accumulation of unchanged drug would not be expected.

Special Populations: Hepatic Function Impairment

Cmax, AUC, and half-life were significantly elevated in patients with moderate to severe liver impairment.

Use: Labeled Indications

Helminths: Treatment of infections caused by the following: All species of Schistosoma (eg, Schistosoma mekongi, S. japonicum, S. mansoni, S. hematobium) and the liver flukes Clonorchis sinensis/Opisthorchis viverrini

Use: Unlabeled

Cysticercosis and many intestinal tapeworms


Hypersensitivity to praziquantel or any component of the formulation; ocular cysticercosis; concomitant administration with strong cytochrome P450 (CYP450) inducers, such as rifampin

Dosing: Adult

Schistosomiasis: Oral: 20 mg/kg/dose 3 times daily at 4- to 6-hour intervals for 1 day

Clonorchiasis/opisthorchiasis: Oral:

Manufacturer’s labeling: 25 mg/kg/dose 3 times daily at 4- to 6-hour intervals for 1 day

Alternate recommendations (off-label dose): 25 mg/kg/dose 3 times daily for 2 days (Drugs for Parasitic Infections 2013)

Cysticercosis (off-label use): Oral: 50 mg/kg/day divided every 8 hours for 14 days (Takayanagui, 2004)

Tapeworms (off-label use): Oral: 5-10 mg/kg as a single dose (25 mg/kg for Hymenolepis nana) (Liu, 1996)

Dosing: Geriatric

Refer to adult dosing.

Dosing: Pediatric

Children ≥4 years and Adolescents: Refer to adult dosing.

Dosing: Renal Impairment

No dosage adjustment necessary.

Dosing: Hepatic Impairment

There are no dosage adjustments provided in manufacturer’s labeling. However, total drug exposure in moderate-to-severe impairment is increased.


Administer tablets with water during meals. Tablets should be promptly swallowed to avoid bitter taste that may cause gagging or vomiting. Tablets may be halved or quartered; do not chew.


Store below 30°C (86°F).

Drug Interactions

Aminoquinolines (Antimalarial): May decrease the serum concentration of Anthelmintics. Monitor therapy

ARIPiprazole: CYP2D6 Inhibitors (Weak) may increase the serum concentration of ARIPiprazole. Management: Monitor for increased aripiprazole pharmacologic effects. Aripiprazole dose adjustments may or may not be required based on concomitant therapy and/or indication. Consult full interaction monograph for specific recommendations. Monitor therapy

Bosentan: May decrease the serum concentration of CYP3A4 Substrates. Monitor therapy

Cimetidine: May increase the serum concentration of Praziquantel. Monitor therapy

CYP3A4 Inducers (Moderate): May decrease the serum concentration of CYP3A4 Substrates. Monitor therapy

CYP3A4 Inducers (Strong): May decrease the serum concentration of Praziquantel. Management: Avoid concomitant use of praziquantel with strong CYP3A4 inducers. Discontinue rifampin 4 weeks prior to initiation of praziquantel therapy. Rifampin may be resumed the day following praziquantel completion. Avoid combination

CYP3A4 Inhibitors (Strong): May increase the serum concentration of Praziquantel. Monitor therapy

Dabrafenib: May decrease the serum concentration of CYP3A4 Substrates. Management: Seek alternatives to the CYP3A4 substrate when possible. If concomitant therapy cannot be avoided, monitor clinical effects of the substrate closely (particularly therapeutic effects). Consider therapy modification

Deferasirox: May decrease the serum concentration of CYP3A4 Substrates. Monitor therapy

Grapefruit Juice: May increase the serum concentration of Praziquantel. Monitor therapy

Osimertinib: May increase the serum concentration of CYP3A4 Substrates. Osimertinib may decrease the serum concentration of CYP3A4 Substrates. Monitor therapy

Siltuximab: May decrease the serum concentration of CYP3A4 Substrates. Monitor therapy

St John's Wort: May decrease the serum concentration of CYP3A4 Substrates. Management: Consider an alternative for one of the interacting drugs. Some combinations may be specifically contraindicated. Consult appropriate manufacturer labeling. Consider therapy modification

Tocilizumab: May decrease the serum concentration of CYP3A4 Substrates. Monitor therapy

Adverse Reactions

Frequency not defined. May be more frequent and/or serious in patients with a heavy worm burden.

Central nervous system: Dizziness, headache, malaise

Dermatologic: Urticaria

Gastrointestinal: Abdominal distress, nausea

Miscellaneous: Fever

<1% (Limited to important or life-threatening): Abdominal pain, atrioventricular block, bloody diarrhea, bradycardia, cardiac arrhythmia, ectopic beats, eosinophilia, hypersensitivity, hypersensitivity reaction, myalgia, paradoxical reaction (in schistosomiasis), polyserositis, pruritus, seizure, serum sickness (in schistosomiasis; Jarisch-Herxheimer-like reaction), skin rash, ventricular fibrillation, vomiting


Disease-related concerns:

• Cardiovascular disease: Use with caution in patients with cardiac abnormalities.

• Cerebral cysticercosis: It is recommended to hospitalize patients with cerebral cysticercosis for the duration of treatment.

• Hepatic impairment: Use with caution in patients with moderate-to-severe hepatic impairment; reduced liver drug metabolism may result in higher and longer lasting plasma concentrations of unmetabolized praziquantel.

• Schistosomiasis: Praziquantel may not be effective against migrating shistosomulae; observational data indicate that praziquantel treatment in the acute phase of the infection may not prevent progression from asymptomatic to acute shistosomiasis, or from asymptomatic/acute disease to chronic disease. In addition, use in patients with shistosomiasis may be associated with clinical deterioration such as paradoxical reactions or serum sickness Jarisch-Herxheimer-like reactions, which is a sudden inflammatory immune response likely caused by the release of shistosomal antigens. Such reactions typically occur during the acute disease phase, and may lead to life-threatening events such as respiratory failure, encephalopathy, and/or cerebral vasculitis.

• Seizures: Use not recommended in patients with a history of seizures or signs of central nervous system involvement (eg, subcutaneous nodules suggestive of cysticercosis); may exacerbate condition.

Concurrent drug therapy issues:

• Drug/drug interactions: Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information. Therapeutic levels of praziquantel may not be achieved with concurrent administration of strong inducers of cytochrome P450 (eg, rifampin); concurrent use is contraindicated.

Other warnings/precautions:

• Patient information: Patients should be instructed to not drive or operate machinery on the day of treatment and the day after treatment.

Monitoring Parameters

Liver function tests; monitor patients with cardiac irregularities during treatment; monitor for seizures; culture urine or feces for ova prior to instituting therapy

Pregnancy Risk Factor


Pregnancy Considerations

Adverse effects have not been observed in animal reproduction studies. Use in pregnant women only if clearly needed.

Patient Education

• Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)

• Patient may experience headache or dyspepsia. Have patient report immediately to prescriber severe dizziness or syncope (HCAHPS).

• Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.

Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for healthcare professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience and judgment in diagnosing, treating and advising patients.