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

Praziquantel Dose in the treatment of Clonorchiasis/ opisthorchiasis:

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

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

• Oral:
  • 50 mg/kg/day in 3 divided daily doses (in combination with albendazole) for 10 to 14 days;
  • The dose may be repeated if persistent viable lesions on 6-month follow-up imaging.

• Note:

  • Initiate adjunctive corticosteroid therapy prior to initiation of antiparasitic therapy.
  • Antiparasitic therapy should not be prescribed in patients with untreated hydrocephalus, calcified lesions, or cysticerci encephalitis;
  • consultation with an infectious disease specialist for specific treatment recommendations is necessary.

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

• Oral: 5 to 10 mg/kg as a single stat dose (25 mg/kg for Hymenolepis nana).

Praziquantel Dose in Childrens

• Note: Dosing interval and duration highly variable dependent on condition; for 3 times daily doses, intervals of 4 to 6 hours are suggested.

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: 25 mg/kg/dose 3 times a day at 4- to 6-hour intervals for 1 to 2 days.

Fasciolopsiasis (Fasciolopsis buski [intestinal fluke]):

• Children and Adolescents:

  • Oral: 25 mg/kg/dose 3 times a day for 1 day.

Paragonimiasis (Paragonimus spp. or lung fluke]):

• Children and Adolescents:

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

Praziquantel Dose in the treatment of Schistosomiasis (Bilharziasis):

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

• Note: Repeat treatment may be needed in 2-4 weeks to increase the effectiveness

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:
    • 40 mg/kg as a single dose;
    • a single dose of 40 mg/kg has been successfully used for the treatment of urogenital S. haematobium in children 1 to 10 years of age and S. mansoni in the population that included infants (age range: 5 months to 7 years)
    • however, pharmacokinetic data shows a lower cure rate in infants and preschool children. one possible explanation is that higher doses may be required in younger patients due to pharmacokinetic/dynamic differences;
    • In preschool children, one dose of 60 mg/kg was successfully used in children 3 to 8 years of age in a hyperendemic area to treat S.mansoni.

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 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.
• The non-emergent treatment for neurocysticercosis may be postponed until after the completion of pregnancy.

Praziquantel use during breastfeeding:

• Breast milk contains Praziquantel.
• One study found that breast milk concentrations of praziquantel 50mg/kg or three 20mg/kg doses was 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 for breastfeeding females.

Praziquantel Dose in Kidney disease:

• No dosage adjustment necessary.

Praziquantel Dose in Liver disease:

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

• May be more frequent and/or serious in patients with a heavy 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, i.e. praziquantel, or any component of its formulation
• 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 of central nervous system:

  • Praziquantel could be used to treat central nervous system disorders such as paragonimiasis or schistosomiasis.
  • Consider whether there is a greater risk for patients who have had seizures in the past or other signs that could indicate central nervous system involvement, such as subcutaneous nodules suggesting cysticercosis.

• Hepatic impairment

  • Take care when you have moderate or severe hepatic impairment.
  • A decreased liver drug metabolism could lead to higher plasma concentrations of nonmetabolized praziquantel.

• Neurocysticercosis:

  • Use only when indicated: Antiparasitic therapy can worsen neurocysticercosis symptoms by inducing an inflammation response.
  • 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 be effective against migrating Schistosomulae
  • Data from observation indicate that praziquantel may not be effective in treating the acute phase.
  • In addition, use in patients with schistosomiasis 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 schistosomal antigens.
  • These reactions are most common during acute phase. They can lead to life-threatening events like 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;
• monitor patients with cardiac irregularities during treatment;
• monitor for seizures;
• culture urine or feces for ova before instituting therapy

How to administer Praziquantel?

• Administer tablets with water during meals.
• Tablets should be swallowed promptly to avoid the bitter taste that may cause gagging or vomiting.
• Tablets may be halved or quartered; do not chew.
• Tablets may be crushed or disintegrated and mixed with semi-solid food or liquid, but should be used within 1 hour of mixing.
• Tablets are scored and may be split into four segments of 150 mg.

Mechanism of action of Praziquantel:

• This increases the cell permeability of calcium in schistosomes.
• It causes strong contractions of worm muscle and paralysis of worms.
• The result is detachment and dislodgment of suckers from blood vessel walls.

Absorption:

• Oral: 80%

Distribution:

• CSF concentration is 14% to 20% of plasma concentration

Protein binding:

• ~80%

Metabolism:

• Extensive first-pass effect; metabolized by the liver 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:

No Brands Available in Pakistan.