Praziquantel

Praziquantel is an anthelmintic drug [see Microbiology (12.4) ] .

• Praziquantel tablets are indicated in patients aged 1 year and older for the treatment of the following infections: Schistosomiasis due to all species of schistosoma (for example, Schistosoma mekongi, Schistosoma japonicum, Schistosoma mansoni and Schistosoma hematobium ), and Clonorchiasis and Opisthorchiasis due to the liver flukes, Clonorchis sinensis/Opisthorchis viverrini (approval of this indication was based on studies in which the two species were not differentiated) Praziquantel tablets are an anthelmintic indicated in patients aged one year and older for the treatment of the following infections: Schistosomiasis due to all species of schistosoma (for example , Schistosoma mekongi , Schistosoma japonicum , Schistosoma mansoni and Schistosoma hematobium ), and, Clonorchiasis and Opisthorchiasis due to the liver flukes, Clonorchis sinensis and Opisthorchis viverrini

• Praziquantel is contraindicated in: Patients who previously have shown hypersensitivity to praziquantel or any of the excipients in praziquantel tablets. Patients with ocular cysticercosis; since parasite destruction within the eye that occurs because of hypersensitivity reaction to the dead parasite after treatment may cause irreversible lesions, ocular cysticercosis must not be treated with praziquantel.contraindicated

Schistosomiasis : 20 mg/kg body weight 3 times a day separated by 4 to 6 hours for 1 day only. ( 2.1 ) Clonorchiasis and Opisthorchiasis : 25 mg/kg 3 times a day separated by 4 to 6 hours for 1 day only. ( 2.1 ) Take with water during meals. Do not chew or keep segments in the mouth. ( 2.2 ) For pediatric patients under 6 years of age, the tablets may be crushed or disintegrated and mixed with semi-solid food or liquid. ( 2.2 ) For additional administration instructions see the full prescribing information. 2.1 Recommended Dosage Schistosomiasis The recommended dosage for the treatment of schistosomiasis is 20 mg/kg bodyweight administered orally three times a day separated by 4 to 6 hours, for 1 day only. Clonorchiasis and Opisthorchiasis The recommended dosage for the treatment of clonorchiasis and opisthorchiasis is 25 mg/kg bodyweight administered orally three times a day separated by 4 to 6 hours for 1 day only. 2.2 Administration Take tablets with water during meals. Do not chew or keep the tablets (or parts of tablets) in the mouth; the bitter taste may cause gagging or vomiting. To prevent choking in pediatric patients under 6 years of age, the tablets may be crushed or disintegrated and mixed with semi-solid food or liquid. Use crushed or disintegrated tablets within 1 hour of mixing. Praziquantel 600 mg tablets have three scores which can be split into four segments at the scores. When broken, each of the four segments contains 150 mg of praziquantel so that the dosage can be adjusted to the patient’s bodyweight.

Clinical Deterioration : Potentially life threatening clinical deterioration can occur in patients treated during the acute phase of schistosomiasis. ( 5.1 ) Central Nervous System (CNS) Effects : Praziquantel can exacerbate central nervous system pathology due to schistosomiasis. Consider whether to administer to individuals reporting a history of epilepsy and/or other signs of potential central nervous systems involvement such as subcutaneous nodules suggestive of cysticercosis. ( 5.2 ) Potential Lack of Efficacy for Acute Schistosomiasis : This has been reported in observational studies ( 5.3 ). Cardiac Arrhythmias: Bradycardia, ectopic rhythms, ventricular fibrillation, and AV blocks has been observed with praziquantel administration. Monitor patients with cardiac arrhythmias during treatment ( 5.4 ). 5.1 Clinical Deterioration The use of praziquantel in patients with schistosomiasis may be associated with clinical deterioration (for example, paradoxical reactions, serum sickness Jarisch-Herxheimer like reactions: sudden inflammatory immune response suspected to be caused by the release of schistosomal antigens). These reactions predominantly occur in patients treated during the acute phase of schistosomiasis. They may lead to potentially life-threatening events, for example, respiratory failure, encephalopathy, papilledema, and/or cerebral vasculitis. 5.2 Central Nervous System (CNS) Effects Praziquantel can exacerbate central nervous system pathology due to schistosomiasis, paragonimiasis, or Taenia solium cysticercosis.

The following serious or otherwise important adverse reactions are discussed elsewhere in the labeling: Clinical Deterioration [see Warnings and Precautions (5.1) ] Central Nervous System (CNS) Effects [see Warnings and Precautions (5.2) ] Potential Lack of Efficacy During the Acute Phase of Schistosomiasis [see Warnings and Precautions (5.3) ] Cardiac Arrhythmias [see Warnings and Precautions (5.4) ] Hepatic Impairment in Hepatosplenic Schistosomiasis Patients [see Warnings and Precautions (5.5) ] Concomitant Administration with Strong Cytochrome P450 Inducers [see Warnings and Precautions (5.6) ] The following adverse reactions associated with the use of praziquantel were identified in clinical studies, published literature or postmarketing reports. Because some of these reactions were reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. The following adverse reactions were observed in both adults and pediatric patients: General disorders and administration site conditions: malaise, pyrexia Nervous system disorders: headache, dizziness Gastrointestinal disorders: abdominal discomfort, nausea Skin and subcutaneous tissue disorders: urticaria Such adverse reactions may be more frequent and/or serious in patients with a heavy worm burden.

Pediatrics : Safety has not been established in pediatric patients younger than 1 year of age. ( 8.4 ) Hepatic Impairment: Monitor patients for adverse reactions when administering the recommended dose of praziquantel to hepatosplenic schistosomiasis patients with moderate to severe liver impairment (Child-Pugh Class B or C). ( 8.6 ) 8.1 Pregnancy Risk Summary Published studies have not identified an association with praziquantel use during pregnancy and major birth defects, miscarriage or adverse maternal or fetal outcomes (see Data) . In animal reproduction studies conducted in pregnant rats and rabbits no adverse developmental outcomes were observed with oral administration of praziquantel during organogenesis at approximately 0.65 times (rats) or 1.3 times (rabbits) the highest recommended human daily dose of 75 mg/kg/day, based on body surface area. The estimated background risk of major birth defects and miscarriage for the indicated population are unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively.

Metabolism

Absorption After oral administration, 80% of an administered praziquantel dose is absorbed, with maximal serum concentrations of praziquantel achieved 1 to 3 hours after dosing. Elimination Following oral administration of praziquantel, the elimination half-life of praziquantel in serum ranges between 0.8 to 1.5 hours.

• Dec 29, 1982NDANDA018714Bayer Hlthcare
• Nov 27, 2017ANDAANDA208820Ph Health

1. 1Drug Ineffective4014%
2. 2Off Label Use3512%
3. 3Pyrexia227.5%
4. 4Product Use In Unapproved Indication217.1%
5. 5Condition Aggravated165.4%
6. 6Headache155.1%
7. 7Vomiting155.1%
8. 8Eosinophilia134.4%
9. 9Seizure134.4%
10. 10Dizziness124.1%
11. 11Schistosomiasis113.7%
12. 12Product Prescribing Issue103.4%
13. 13Urticaria103.4%
14. 14Abdominal Pain93.1%
15. 15Diarrhoea93.1%

Recent PubMed references pinned to Praziquantel as a MeSH major topic. Citations link to pubmed.ncbi.nlm.nih.gov.

• Evaluation of the antiparasitic efficacy of praziquantel against Prohemistomum vivax (Cyathocotylidae) metacercariae in naturally infected African catfish (Clarias gariepinus).
  Scientific reports · 2026 · Abdelsalam M, Abdelkhalek S, Korany RMS, et al.
  PMID 42162023DOI 10.1038/s41598-026-46340-0
• Nitazoxanide Exhibits Schistosomicidal Activity Against Schistosomula and Adult Schistosoma mansoni and Influences Praziquantel-Associated Outcomes.
  Acta parasitologica · 2026 · Da Costa CJ, Gama JEM, Silva AJM, et al.
  PMID 42126719DOI 10.1007/s11686-026-01269-2
• Does protein malnutrition modulate Schistosoma mansoni response to praziquantel? Assessment of adult helminth morphology.
  Parasitology international · 2026 · Sanches M, Bernardo J, Brandão-Bezerra L, et al.
  PMID 42066950DOI 10.1016/j.parint.2026.103292
• Comparison of nitroxynil, praziquantel and their combination in the treatment against natural infections of Eurytrema coelomaticum in cattle.
  Veterinary parasitology, regional studies and reports · 2026 · Pantiu AJ, Häberle T, Cholich L, et al.
  PMID 42034964DOI 10.1016/j.vprsr.2026.101483
• Efficacy of NexGard® combo (esafoxolaner-eprinomectin-praziquantel) against natural Mammomonogamus ierei infection in cats.
  Veterinary parasitology, regional studies and reports · 2026 · Iani AD, Mihalca AD, Beugnet F, et al.
  PMID 42034956DOI 10.1016/j.vprsr.2026.101474
• Efficacy of a single-dose topical formulation combining Fipronil, Moxidectin and Praziquantel against natural infestations of Notoedres cati, Otodectes cynotis and Felicola subrostratus in cats.
  Revista brasileira de parasitologia veterinaria = Brazilian journal of veterinary parasitology : Orgao Oficial do Colegio Brasileiro de Parasitologia Veterinaria · 2026 · Campos DR, Soares EFMS, Cruz BC, et al.
  PMID 41983805DOI 10.1590/S1984-29612025080
• Access to praziquantel in Italy: persistent gaps and ongoing responses amid a Europe-wide shortage.
  Infectious diseases of poverty · 2026 · Marrone R, Camponi C, Cammarata S, et al.
  PMID 41975501DOI 10.1186/s40249-026-01435-8
• Coverage validation survey of preventive chemotherapy for schistosomiasis in interruption of transmission districts of Ethiopia, 2025.
  Infectious diseases of poverty · 2026 · Churko C, Kassahun AB, Zerdo Z, et al.
  PMID 41933407DOI 10.1186/s40249-026-01439-4

The 10 most recently updated of 57 ClinicalTrials.gov registrations naming Praziquantel as an intervention. Registration is not evidence of efficacy or safety — reference crosswalk only.

• Oxfendazole in Mild Parenchymal Brain Cysticercosis
  Not yet recruiting · Phase 2 · Phase 3 · Interventional · 544 enrolled · Universidad Peruana Cayetano Heredia
  NCT06565507updated 2026-05-01
• Praziquantel in Children Under Age 4
  Completed · Phase 2 · Interventional · 354 enrolled · Rhode Island Hospital
  NCT03640377updated 2026-04-23
• Efficacy of Bilhvax in Association With Praziquantel for Prevention of Clinical Recurrences of Schistosoma Haematobium
  Completed · Phase 3 · Interventional · 250 enrolled · Institut National de la Santé Et de la Recherche Médicale, France
  NCT00870649updated 2025-12-10
• Introduction of Arpraziquantel Treatment for Schistosomiasis Control in Preschool-aged Children in Endemic Areas: A Small-scale Public Health Intervention Study
  Recruiting · Observational · 18,500 enrolled · Peter Steinmann
  NCT06698510updated 2025-09-24
• Treatment of Clonorchiasis in Guangxi With Albendazole, Tribendimidine, and Praziquantel
  Recruiting · Phase 4 · Interventional · 318 enrolled · First Affiliated Hospital of Guangxi Medical University
  NCT07074444updated 2025-08-17
• HIV And Parasitic Infection (HAPI) Study
  Completed · Interventional · 120 enrolled · University of North Carolina, Chapel Hill
  NCT05323396updated 2025-07-16
• Assessment of Combined Praziquantel and Albendazole vs Albendazole Alone to Treat Active Parenchymal Neurocysticercosis
  Not yet recruiting · Phase 4 · Interventional · 300 enrolled · R-Evolution Worldwide S.r.l. Impresa Sociale
  NCT06376396updated 2024-04-23
• L-PZQ ODT in Schistosoma Infected Children
  Completed · Phase 3 · Interventional · 288 enrolled · Merck KGaA, Darmstadt, Germany
  NCT03845140updated 2024-03-21
• Effectiveness and Cost-effectiveness of Integrated Model for Malaria and Helminth Control
  Unknown · Interventional · 1,200 enrolled · London School of Hygiene and Tropical Medicine
  NCT06182176updated 2024-03-20
• Adoption of L-PZQ for Schistosomiasis by Endemic Counties - Social Science Research Study
  Unknown · Observational · 225 enrolled · Technical University of Munich
  NCT05350462updated 2023-12-01

Frequently asked questions

How does Praziquantel work?

Praziquantel is an anthelmintic drug [see Microbiology (12.4) ] .

What is Praziquantel used for?

According to FDA labeling, Praziquantel carries indications including: Praziquantel tablets are indicated in patients aged 1 year and older for the treatment of the following infections: Schistosomiasis due to all species of schistosoma (for example, Schistosoma mekongi, Schistosoma japonicum, Schistosoma mansoni and Schistosoma hematobium ), and Clonorchiasis and Opisthorchiasis due to the liver flukes, Clonorchis sinensis/Opisthorchis viverrini (approval of this indication was based on studies in which the two species were not differentiated) Praziquantel tablets are an anthelmintic indicated in patients aged one year and older for the treatment of the following infections: Schistosomiasis due to all species of schistosoma (for example , Schistosoma mekongi , Schistosoma japonicum , Schistosoma mansoni and Schistosoma hematobium ), and, Clonorchiasis and Opisthorchiasis due to the liver flukes, Clonorchis sinensis and Opisthorchis viverrini. This is a reference summary of labeled uses, not medical advice or a treatment recommendation.

What class of drug is Praziquantel?

Praziquantel is classified as Quinoline derivatives and related substances, Anthelmintic, Calcium Channel Interactions, Increased Cell Membrane Integrity.

What are the brand names for Praziquantel?

Praziquantel is marketed under brand names including Biltricide, Droncit, Drontal, Drontal Plus, Equimax, Giarcidia, Interceptor Plus, Iverhart.

What are the contraindications for Praziquantel?

Praziquantel labeling lists contraindications including: Praziquantel is contraindicated in: Patients who previously have shown hypersensitivity to praziquantel or any of the excipients in praziquantel tablets. Patients with ocular cysticercosis; since parasite destruction within the eye that occurs because of hypersensitivity reaction to the dead parasite after treatment may cause irreversible lesions, ocular cysticercosis must not be treated with praziquantel.. Always consult the full prescribing information and a clinician.