Praziquantel (Biltricide) is an antihelminthic medicine that is used to treat most infections caused by cestodes and schistosomes.

Praziquantel Uses:

• Helminths:

  • Treatment of infections in patients ≥1 year caused by the following species of Schistosoma:
    • Schistosoma mekongi,
    • S. japonicum,
    • S. mansoni,
    • S. hematobium) and the
    • liver flukes (Clonorchis sinensis/ Opisthorchis viverrini)

• Off-Label Use of Praziquantel in Adults:

  • Neurocysticercosis, parenchymal;
  • Tapeworms

Praziquantel Dose in Adults

Praziquantel Dose in the Treatment of Schistosomiasis:

• Oral: Dosage of 20 mg/kg 3 times a day for one day, spaced 4- to 6 hours apart.

Praziquantel Dose in the treatment of Clonorchiasis/ opisthorchiasis:

• Oral: 3 times a day for 1 to 2 days at a dose of 25 mg/kg.

Praziquantel Dose in the treatment of parenchymal Neurocysticercosis (>2 viable cysts) (off-label):

• Oral:
  • For 10 to 14 days, administer 50 mg/kg/day in three evenly spaced doses (in conjunction with albendazole); repeat the dose if 6-month follow-up imaging reveals persistent viable lesions.

• Note:

  • Before beginning antiparasitic therapy, begin adjunctive corticosteroid therapy.
  • Patients with untreated hydrocephalus, calcified lesions, or cysticerci encephalitis should not get antiparasitic therapy; instead, an infectious disease specialist should be consulted for particular therapeutic advice.

Praziquantel Dose in the treatment of Tapeworms (off-label):

• Oral: As a single stat dosage, administer 5 to 10 mg/kg (25 mg/kg for Hymenolepis nana).

Praziquantel Dose in Children:

• Note: The period between doses is highly variable and depends on the patient's condition; intervals of 4 to 6 hours are recommended for doses given three times daily.

Praziquantel Dose in the Treatment of Flukes:

Clonorchiasis (Clonorchis sinensis or Chinese liver fluke); Opisthorchiasis (Opisthorchis viverrini or Southeast Asian liver fluke):

• Children and Adolescents:

  • Oral: Dosage of 25 mg/kg For one to two days, 3 times per day at 4- to 6-hour intervals.

Fasciolopsiasis (Fasciolopsis buski [intestinal fluke]):

• Children and Adolescents:

  • Oral: 3 doses of 25 mg/kg per day for one day.

Paragonimiasis (Paragonimus spp. or lung fluke]):

• Children and Adolescents:

  • Oral: Dosage of 25 mg/kg 3 times every day for two to three days.

Praziquantel Dose in the treatment of Schistosomiasis (Bilharziasis):

Treatment (CDC 2018c; Red Book [AAP 2018]):

• Note: Dosage of 25 mg/kg 3 times every day for two to three days.

Schistosoma japonicum and Schistosoma mekongi:

• Children and Adolescents:

  • Oral: 20 mg/kg/dose 3 times a day for 1 day

Schistosoma mansoni, Schistosoma haematobium, and Schistosoma intercalatum:

• Children and Adolescents:

  • Oral: 20 mg/kg/dose twice a day for 1 day

Control programs for endemic areas:

• Infants, Children, and Adolescents:

  • Oral:
    • A single dose of 40 mg/kg has been used successfully to treat S. mansoni in the population that included infants (aged 5 months to 7 years) and urogenital S. haematobium in children aged 1 to 10; however, pharmacokinetic evidence indicates a decreased cure rate in young children and infants.
    • One argument is that younger patients may need higher dosages due to pharmacokinetic/dynamic variations.
    • For example, in young children, a single dose of 60 mg/kg was successfully utilised to treat S.mansoni in children between the ages of 3 and 8 in a hyperendemic location.

Praziquantel Dose in the Treatment of Tapeworms:

Praziquantel for the treatment of the intestinal (Adult) stage of Diphyllobothrium latum (fish tapeworm), Taenia saginata (beef tape worm), Taenia solium (pork tapeworm):

• Children and Adolescents:

  • Oral: 5 to 10 mg/kg as a single stat dose

Praziquantel for the treatment of the intestinal stage (adult stage) of Dipylidium caninum:

• Infants ≥6 months, Children, and Adolescents:

  • Oral: 5 to 10 mg/kg as a single stat dose

Praziquantel for the treatment of Hymenolepis nana (dwarf tapeworm):

• Children and Adolescents:

  • Oral: 25 mg/kg as a single dose

Praziquantel for tissue stage (larva stage) of Neurocysticercosis (Taenia solium or pork tapeworm):

• Children and Adolescents:

  • Oral: 50 mg/kg/day for 15 days.
  • Note: May be used in conjunction with antiseizure medication and/or corticosteroids.

Praziquantel Pregnancy Category: B

• According to available data, there has been no evidence of an increase in maternal or fetal outcomes after the use of Praziquantel during Schistosoma treatment.
• The World Health Organization recommends that pregnant women receive praziquantel in areas where soil-transmitted and schistosomiasis are common.
• Neurocysticercosis non-emergent treatment may be delayed until after the pregnancy is over.

Praziquantel use during breastfeeding:

• Breast milk contains Praziquantel.
• One study found that breast milk concentrations of praziquantel 50mg/kg or three 20mg/kg doses were 1% after maternal use.
• According to the manufacturer breastfeeding during therapy is a decision that should be made after considering the risks to infants and the benefits to mothers.
• The World Health Organization considers that praziquantel is compatible with breastfeeding females.

Praziquantel Dose in Kidney Disease:

• No dosage adjustment is necessary.

Praziquantel Dose in Liver Disease:

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

• Occurrence and/or severity may be increased in patients with a high worm burden.

Side effects of Praziquantel

• Central nervous system:

  • Dizziness
  • Headache
  • Malaise

• Dermatologic:

  • Urticaria

• Gastrointestinal:

  • Abdominal distress
  • Nausea

• Miscellaneous:

  • Fever

Contraindications to Praziquantel:

• Hypersensitivity to the primary drug
• ocular cysticercosis;
• a concomitant prescription with strong cytochrome P450 (CYP450) inducers, such as rifampin

Warnings and precautions

• Cardiac arrhythmias:

  • During treatment, monitor patients suffering from arrhythmias;
  • Praziquantel administration has been linked to a variety of conditions including ectopic rhythms and ventricular fibrillation.

• Effects on central nervous system:

  • Praziquantel could be used to treat central nervous system disorders such as paragonimiasis or schistosomiasis.
  • Think about whether patients who have previously experienced seizures or other symptoms that could point to central nervous system involvement, including subcutaneous nodules that could point to cysticercosis, are at a higher risk.

• Hepatic impairment

  • Take care when you have moderate or severe hepatic impairment.
  • Praziquantel plasma concentrations could increase as a result of impaired liver drug metabolism.

• Neurocysticercosis:

  • Use only as directed: By triggering an inflammatory reaction, antiparasitic therapy can make the symptoms of neurocysticercosis worse.
  • It is important to start adjunctive corticosteroid treatment before you begin antiparasitic therapies.
  • Untreated hydrocephalus, cysticerci, and calcified lesions should not be treated with antiparasitic treatment.
  • To exclude intraocular cysticerci, perform a funduscopic examination before initiating antiparasitic treatment. In some cases of unsuspected intraocular parasites, antiparasitic treatment may result in blindness.

• Schistosomiasis:

  • Praziquantel might not have any effect on migratory Schistosomulae
  • Praziquantel may not be useful in treating the acute phase, according to observational data.
  • Additionally, use in schistosomiasis patients may be linked to clinical side effects such as paradoxical reactions or serum sickness. An abrupt inflammatory immunological response known as a Jarisch-Herxheimer-like reaction is most likely brought on by the release of schistosomal antigens.
  • The acute period is when these reactions occur most frequently. They may result in potentially fatal conditions such as respiratory failure, encephalopathy, and papilledema.

Praziquantel: Drug Interaction

Note: Drug Interaction Categories:

• Risk Factor C: Monitor When Using Combination
• Risk Factor D: Consider Treatment Modification
• Risk Factor X: Avoid Concomitant Use

Monitoring parameters:

• Liver function tests

• cardiac irregularities 

• seizures

• culture urine or feces for ova before instituting therapy

How to administer Praziquantel?

• When eating, take the pills with water.
• The bitter taste of the tablets should be quickly taken to prevent gagging or vomiting.
• Do not chew the tablet; it may be cut in half or quarters.
• Tablets can be broken up or dissolved, then combined with semi-solid food or liquid; however, this mixture should be consumed within an hour.
• The scored tablets can be divided into four pieces, each containing 150 mg.

Mechanism of action of Praziquantel:

Praziquantel makes calcium more permeable to cells in schistosomes. This leads to strong muscle spasms and worm paralysis.

As a result, suckers are detached from blood vessel walls and knocked loose.

Absorption:

• Oral: 80%

Distribution:

• CSF concentrations range from 14% to 20% of plasma levels.

Protein binding:

• ~80%

Metabolism:

• Significant first-pass impact; liver metabolizes to hydroxylated and conjugated metabolites

Half-life elimination:

• Parent drug: 0.8 to 1.5 hours;
• Metabolites: 4.5 hours

Time to peak, serum:

• 1 to 3 hours

Excretion:

• Urine ~80% (>99% as metabolites)

International Brands of Praziquantel:

• Biltricide
• Belicide
• Biltricid
• Biltricide
• Cesol
• Cisticid
• Cysticide
• Distocide
• Droncit Vet
• Epiquantel
• Fluxide
• Kalcide
• Opticide
• Prasikon
• Prazine
• Praziquin
• Prazite
• Prazitral
• Vermaqpharma Vet
• Wormicide

Praziquantel Brand Names in Pakistan:

Not available.