Identification
- Summary
Pyrantel is an anthelmintic used to treat helminth infections.
- Brand Names
- Pronto Plus Pinworm, Pyral
- Generic Name
- Pyrantel
- DrugBank Accession Number
- DB11156
- Background
Pyrantel is a pyrimidine-derivative anthelmintic agent for the oral treatment of various parasitic worm infections including ascariasis, hookworm infections, enterobiasis (pinworm infection), trichostrongyliasis, and trichinellosis 17.
Pyrantel was initially described in 1965 by researchers from Pfizer who sought cyclic amidines with suitable pharmacokinetic properties (specifically, duration of action) for use as an anthelmintic drug. Pyrantel is mainly available in formulations for dogs and cats as the embonate salt, containing a 34.7% pyrantel base 14.
Pyrantel is on the World Health Organization's List of Essential Medicines, which are the safest and most effective medicines required in a functioning health system 15, 16.
A depolarizing neuromuscular-blocking agent causing longstanding nicotinic receptor activation, resulting in spastic paralysis of susceptible nematodes (worms). Pyrantel has shown to be effective after a single dose 18.
- Type
- Small Molecule
- Groups
- Approved, Vet approved
- Structure
Structure for Pyrantel (DB11156)
- Weight
- Average: 206.31
Monoisotopic: 206.087769633 - Chemical Formula
- C11H14N2S
- Synonyms
- Pirantel
- Pyrantel
- Pyrantelum
Pharmacology
- Indication
For the treatment of enterobiasis including roundworm (ascariasis), pinworm (enterobius) and hookworm (strongyloides) and hookworm (ancylostoma) in the pyrantel pamoate form 8.
Pyrantel is available in various formulations for humans, dogs, and cats as the pamoate (US Pharmacopeia nomenclature) or embonate (European Pharmacopoeia nomenclature) salt, which contains 34.7% pyrantel base combined with pamoic acid 8. 14, 4.
Pyrantel pamoate (embonate) ingested orally is effective for removal and control of ascarid and hookworm infections in puppies and dogs (adult Toxocara canis, Toxascaris leonina, Ancylostoma tubaeforme, An. braziliense, Uncinaria stenocephala), cats (adult Toxocara cati, Toxa. leonina, An. caninum, An. braziliense, U. stenocephala), horses and ponies (adult and immature Parascaris equorum, adult Strongylus vulgaris, S. edentatus, S. equinus, Cyathostomes (Triodontophorus spp., Cyathostomum spp., Cylicodontophorus spp., Cylicocyclus spp., Cylicostephanus spp., Poteriostomum spp.), Oxyuris equi, Anoplocephala perfoliata), swine (adult Ascaris suum, Oesophagostomum dentatum), and humans (adult A. lumbricoides, Enterobius vermicularis, An. duodenale, Necator americanus) 14.
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- Contraindications & Blackbox Warnings
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It has similar properties to both competitive and depolarizing neuromuscular blocking agents, which leads to the understanding of the paralytic effect of the drug has on parasites, ultimately resulting in the death of the parasite 16, 8.
- Mechanism of action
By promoting the release of acetylcholine, inhibiting cholinesterase, and stimulating ganglionic neurons, pyrantel serves as a depolarizing neuromuscular blocking agent in helminths. This causes extensive depolarization of the helminth muscle membrane, resulting in tension to the helminth's muscles, leading to paralysis and release of their attachment to the host organism intestinal walls 8.
This action is unlike piperazine, which is a hyperpolarizing neuromuscular blocking agent that causes relaxation of the helminth muscles, leading to a subsequent detachment from the intestinal wall. Excretion of the parasites in the feces occurs by normal peristalsis 7.
Target Actions Organism UG-protein coupled receptor 35 Not Available Humans NMuscarinic acetylcholine receptor M1 antagonistagonistHumans - Absorption
Pyrantel is poorly absorbed from the GI tract of humans 8, 21.
Peak serum concentrations occur 1–3 hours after a single dose 17.
- Volume of distribution
Not Available
- Protein binding
Not Available
- Metabolism
Pyrantel is administered orally. The poor solubility of the pamoate salt offers the advantage of reduced absorption from the gastrointestinal tract and allows the drug to reach and act against parasites in the large intestine. Metabolism of pyrantel is rapid 22. The absorbed drug is partly metabolized in the liver 20.
- Route of elimination
Approximately 50% of an oral dose is excreted unchanged in feces; 7% excreted in urine as unchanged drug and metabolites 17.
- Half-life
In pigs, following intravenous administration, pyrantel exhibited a half-life of 1.75 +/- 0.19 h 5.
- Clearance
Not Available
- Adverse Effects
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Mild adverse effects include nausea, vomiting, diarrhea, headache, and dizziness 8.
LD50 in rats is 535 mg/kg 10.
Reported effects in humans in case of overdose include gastrointestinal disturbance, central nervous system effects, and superficial skin reactions. In one study, serum aspartate aminotransferase (AST) and serum alanine-aminotransferase (ALT) values were increased in approximately 2% of patients 19.
Pyrantel should be used with caution in patients with severe malnutrition or anemia. Supportive therapy is recommended for anemic, dehydrated, or malnourished patients before administration of the drug 12.
Pyrantel pamoate has been placed in pregnancy category C. This refers to the fact that animal studies have revealed adverse effects on the fetus (teratogenic/embryocidal, or other) and there are no controlled studies in women or studies in women and animals are not available. Drugs should be given only if the potential benefit justifies the potential risk to the fetus 9.Data on the use of pyrantel pamoate in pregnant women are quite limited. In mass treatment programs for which the World Health Organization (WHO) has observed that the benefits of treatment outweigh the risks, WHO allows the use of pyrantel pamoate in the 2nd and 3rd trimesters of pregnancy, due to the fact that the effects of pyrantel on birth outcome are uncertain. The risk of treatment in pregnant women already known to have an infection needs to be balanced with the risk of disease progression if treatment were to be omitted 9. Individuals with liver disease are more susceptible to the toxicity in cases of pyrantel overexposure 9, 11.
There are no data regarding the presence of pyrantel in breast milk. Pyrantel is poorly absorbed from the GI tract; therefore, excretion into breast milk may be minimal. Some experts recommend that a single dose of pyrantel therapy may be given to breastfeeding women 8.
- Pathways
- Not Available
- Pharmacogenomic Effects/ADRs
- Not Available
Interactions
- Drug Interactions
- This information should not be interpreted without the help of a healthcare provider. If you believe you are experiencing an interaction, contact a healthcare provider immediately. The absence of an interaction does not necessarily mean no interactions exist.
Drug Interaction Integrate drug-drug
interactions in your software1,2-Benzodiazepine The risk or severity of adverse effects can be increased when Pyrantel is combined with 1,2-Benzodiazepine. Abacavir Abacavir may decrease the excretion rate of Pyrantel which could result in a higher serum level. Aceclofenac Aceclofenac may decrease the excretion rate of Pyrantel which could result in a higher serum level. Acemetacin Acemetacin may decrease the excretion rate of Pyrantel which could result in a higher serum level. Acetaminophen Acetaminophen may decrease the excretion rate of Pyrantel which could result in a higher serum level. Acetazolamide The risk or severity of adverse effects can be increased when Acetazolamide is combined with Pyrantel. Acetophenazine The risk or severity of adverse effects can be increased when Acetophenazine is combined with Pyrantel. Acetyldigitoxin The risk or severity of Cardiac Arrhythmia can be increased when Pyrantel is combined with Acetyldigitoxin. Acetylsalicylic acid Acetylsalicylic acid may decrease the excretion rate of Pyrantel which could result in a higher serum level. Aclidinium Pyrantel may increase the central nervous system depressant (CNS depressant) activities of Aclidinium. 
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- No interactions found.
Products
Drug product information from 10+ global regionsOur datasets provide approved product information including:dosage, form, labeller, route of administration, and marketing period.Access drug product information from over 10 global regions.- Product Ingredients
Ingredient UNII CAS InChI Key Pyrantel citrate 1YXE665Z2S 5685-86-9 YJGGCARNRYGSPA-IPZCTEOASA-N Pyrantel pamoate 81BK194Z5M 22204-24-6 AQXXZDYPVDOQEE-MXDQRGINSA-N Pyrantel tartrate SC82VF0480 33401-94-4 VWRCYAZJKNPEQR-NIEARKAZSA-N - Brand Name Prescription Products
Name Dosage Strength Route Labeller Marketing Start Marketing End Region Image Jaa Pyral 35 Tablet 35mg Tablet 35 mg Oral Jaapharm Canada Inc. 1989-12-31 Not applicable Canada 
- Over the Counter Products
Name Dosage Strength Route Labeller Marketing Start Marketing End Region Image BEARANTEL TABLETS 125 mg Tablet 125 mg Oral BEACONS PHARMACEUTICALS PTE. LTD. 1988-06-08 Not applicable Singapore Combantrin Oral Suspension 50mg/ml Suspension 50 mg / mL Oral Mcneil Consumer Healthcare Division Of Johnson & Johnson Inc 1973-12-31 Not applicable Canada Combantrin Tab 125mg Tablet 125 mg Oral Mcneil Consumer Healthcare Division Of Johnson & Johnson Inc 1973-12-31 Not applicable Canada CVS Pinworm Treatment Suspension 144 mg/1mL Oral CVS Pharmacy Inc 2016-12-15 Not applicable US 
DYNA PAR (WORM SUSPENSION) 125MG/5ML Suspension Oral DYNAPHARM (M) SDN BHD 2020-09-08 Not applicable Malaysia 
Jaa Pyral 125 Tablet 125mg Tablet 125 mg Oral Jaapharm Canada Inc. 1998-11-27 Not applicable Canada Jaa Pyral P Oral Paste - 125mg/g Paste 125 mg / g Oral Jaapharm Canada Inc. 1995-12-31 Not applicable Canada Jaa Pyral S Suspension 50mg/76 Suspension 50 mg / mL Oral Jaapharm Canada Inc. 1995-12-31 Not applicable Canada Jamp-pyrantel Pamoate Tablet 125 mg Oral Jamp Pharma Corporation 2013-12-13 Not applicable Canada Jamp-pyrantel Pamoate Suspension Suspension 50 mg / mL Oral Jamp Pharma Corporation 2014-03-25 Not applicable Canada - Mixture Products
Name Ingredients Dosage Route Labeller Marketing Start Marketing End Region Image PAMOATO DE OXANTEL 250 MG/5ML + PAMOATO DE PIRANTEL 250 MG/5 ML SUSPENSIÓN. Pyrantel pamoate (5 g) + Oxantel pamoate (5 g) Suspension Oral COASPHARMA S.A.S. 2008-01-09 Not applicable Colombia 
PIRAXTEL® SUSPENSION Pyrantel pamoate (5 g) + Oxantel pamoate (5 g) Suspension Oral LABORATORIOS COASPHARMA S.A.S - COASPHARMA S.A.S 2007-04-09 Not applicable Colombia
Categories
- ATC Codes
- P02CC01 — Pyrantel
- Drug Categories
- Anthelmintics
- Anti-Infective Agents
- Antinematodal Agents
- Antiparasitic Agents
- Antiparasitic Products, Insecticides and Repellents
- Central Nervous System Depressants
- Drugs that are Mainly Renally Excreted
- Neuromuscular Agents
- Neuromuscular Blocking Agents
- Neuromuscular Depolarizing Agents
- Peripheral Nervous System Agents
- Pyrimidines
- Sulfur Compounds
- Tetrahydropyrimidine Derivatives
- Thiophenes
- Chemical TaxonomyProvided by Classyfire
- Description
- This compound belongs to the class of organic compounds known as hydropyrimidines. These are compounds containing a hydrogenated pyrimidine ring (i.e. containing less than the maximum number of double bonds.).
- Kingdom
- Organic compounds
- Super Class
- Organoheterocyclic compounds
- Class
- Diazines
- Sub Class
- Pyrimidines and pyrimidine derivatives
- Direct Parent
- Hydropyrimidines
- Alternative Parents
- Imidolactams / Thiophenes / Heteroaromatic compounds / Propargyl-type 1,3-dipolar organic compounds / Carboximidamides / Carboxamidines / Azacyclic compounds / Organopnictogen compounds / Hydrocarbon derivatives
- Substituents
- 1,4,5,6-tetrahydropyrimidine / Amidine / Aromatic heteromonocyclic compound / Azacycle / Carboximidamide / Carboxylic acid amidine / Heteroaromatic compound / Hydrocarbon derivative / Hydropyrimidine / Imidolactam
- Molecular Framework
- Aromatic heteromonocyclic compounds
- External Descriptors
- carboxamidine, thiophenes, 1,4,5,6-tetrahydropyrimidines (CHEBI:8654)
- Affected organisms
- Humans
Chemical Identifiers
- UNII
- 4QIH0N49E7
- CAS number
- 15686-83-6
- InChI Key
- YSAUAVHXTIETRK-AATRIKPKSA-N
- InChI
- InChI=1S/C11H14N2S/c1-13-8-3-7-12-11(13)6-5-10-4-2-9-14-10/h2,4-6,9H,3,7-8H2,1H3/b6-5+
- IUPAC Name
- 1-methyl-2-[(E)-2-(thiophen-2-yl)ethenyl]-1,4,5,6-tetrahydropyrimidine
- SMILES
- [H]\C(=C(\[H])C1=NCCCN1C)C1=CC=CS1
References
- General References
- Aubry ML, Cowell P, Davey MJ, Shevde S: Aspects of the pharmacology of a new anthelmintic: pyrantel. Br J Pharmacol. 1970 Feb;38(2):332-44. [Article]
- Rayes D, De Rosa MJ, Spitzmaul G, Bouzat C: The anthelmintic pyrantel acts as a low efficacious agonist and an open-channel blocker of mammalian acetylcholine receptors. Neuropharmacology. 2001 Aug;41(2):238-45. [Article]
- Gokbulut C, Aksit D, Smaldone G, Mariani U, Veneziano V: Plasma pharmacokinetics, faecal excretion and efficacy of pyrantel pamoate paste and granule formulations following per os administration in donkeys naturally infected with intestinal strongylidae. Vet Parasitol. 2014 Sep 15;205(1-2):186-92. doi: 10.1016/j.vetpar.2014.06.026. Epub 2014 Jun 26. [Article]
- Fasanmade AA, Akanni AO, Olaniyi AA, Fasanmade AA, Tayo F: Bioequivalence of pyrantel pamoate dosage forms in healthy human subjects. Biopharm Drug Dispos. 1994 Aug;15(6):527-34. [Article]
- Bjorn H, Hennessy DR, Friis C: The kinetic disposition of pyrantel citrate and pamoate and their efficacy against pyrantel-resistant Oesophagostomum dentatum in pigs. Int J Parasitol. 1996 Dec;26(12):1375-80. [Article]
- Li XQ, Bjorkman A, Andersson TB, Gustafsson LL, Masimirembwa CM: Identification of human cytochrome P(450)s that metabolise anti-parasitic drugs and predictions of in vivo drug hepatic clearance from in vitro data. Eur J Clin Pharmacol. 2003 Sep;59(5-6):429-42. Epub 2003 Aug 12. [Article]
- Pharmacokinetics of praziquantel and pyrantel pamoate combination following oral administration in cats [Link]
- Pyrantel Pamoate PDR [Link]
- CDC for healthcare professionals [Link]
- MSDS for pyrantel [Link]
- Strongidpaste [Link]
- Pyrantel Dosage [Link]
- Pyrantel Pamoate [Link]
- Pyrantel, Science Direct [Link]
- Pediatric Ascaris Medication [Link]
- Summary of product characteristics [Link]
- Pyrantel Pamoate Monograph [Link]
- Pyrantel MeSH NIH [Link]
- Principles and Practice of Infectious Diseases [Link]
- Pharmacotherapeutics For Advanced Practice Nurse Prescribers [Link]
- Delmar Nurse's Drug Handbook 2012 Edition [Link]
- MSD vet manual [Link]
- DailyMed: Pyrantel pamoate oral suspension [Link]
- INVIMA Product Information: Vanpar (pirantel pamoate/oxantel pamoate) oral suspension [Link]
- External Links
- KEGG Drug
- D08451
- KEGG Compound
- C07409
- PubChem Compound
- 708857
- PubChem Substance
- 347827925
- ChemSpider
- 618121
- 8984
- ChEBI
- 8654
- ChEMBL
- CHEMBL1626223
- ZINC
- ZINC000000097996
- Wikipedia
- Pyrantel
- MSDS
- Download (41.8 KB)
Clinical Trials
- Clinical Trials
Phase Status Purpose Conditions Count 4 Completed Treatment Drug Resistance / Helminths Infection 1 4 Completed Treatment Hookworm Infections 1 4 Completed Treatment Infection by Trichuris Trichiura 1 Not Available Recruiting Prevention Infection / Malnutrition 1
Pharmacoeconomics
- Manufacturers
- Not Available
- Packagers
- Not Available
- Dosage Forms
Form Route Strength Suspension Oral 5 MG/100mL Syrup Oral 5 mg/100l Tablet Oral Tablet Oral 250 MG Tablet, chewable Oral Tablet Oral 734.87 mg Suspension Oral Tablet Oral 360.23 MG Tablet Oral 719.23 mg Tablet, chewable Oral Tablet Oral Tablet Oral 280.74 mg Tablet Oral 35 mg Paste Oral 125 mg / g Suspension Oral 50 mg / mL Capsule, liquid filled Oral 250 mg Tablet, coated Oral 250 mg Suspension Oral 5000 mg Suspension Oral Suspension Oral 5 g Tablet, chewable Oral 250 mg/1 Suspension Oral 50 mg/1mL Tablet Oral 250 mg/1 Suspension Oral 144 mg/1mL Tablet Oral 757.577 mg Tablet, coated Oral Suspension Oral 5 g Tablet Oral 720 mg Liquid Oral 5 mL/250mL Powder Not applicable 1 g/1g Suspension Oral 5 g/100mL Tablet Oral 180 mg/1 Tablet, film coated Oral Syrup Oral Suspension Oral 125 mg/5ml Tablet Oral 360 mg Suspension Oral 250 mg/5mL Tablet Oral 125 mg - Prices
- Not Available
- Patents
- Not Available
Properties
- State
- Solid
- Experimental Properties
Property Value Source water solubility insoluble in water MSDS - Predicted Properties
Property Value Source Water Solubility 0.118 mg/mL ALOGPS logP 2.69 ALOGPS logP 1.96 ChemAxon logS -3.2 ALOGPS pKa (Strongest Basic) 10.71 ChemAxon Physiological Charge 1 ChemAxon Hydrogen Acceptor Count 2 ChemAxon Hydrogen Donor Count 0 ChemAxon Polar Surface Area 15.6 Å2 ChemAxon Rotatable Bond Count 2 ChemAxon Refractivity 61.81 m3·mol-1 ChemAxon Polarizability 23.32 Å3 ChemAxon Number of Rings 2 ChemAxon Bioavailability 1 ChemAxon Rule of Five Yes ChemAxon Ghose Filter Yes ChemAxon Veber's Rule Yes ChemAxon MDDR-like Rule No ChemAxon - Predicted ADMET Features
- Not Available
Spectra
- Mass Spec (NIST)
- Not Available
- Spectra
Spectrum Spectrum Type Splash Key Predicted GC-MS Spectrum - GC-MS Predicted GC-MS Not Available Predicted MS/MS Spectrum - 10V, Positive (Annotated) Predicted LC-MS/MS Not Available Predicted MS/MS Spectrum - 20V, Positive (Annotated) Predicted LC-MS/MS Not Available Predicted MS/MS Spectrum - 40V, Positive (Annotated) Predicted LC-MS/MS Not Available Predicted MS/MS Spectrum - 10V, Negative (Annotated) Predicted LC-MS/MS Not Available Predicted MS/MS Spectrum - 20V, Negative (Annotated) Predicted LC-MS/MS Not Available Predicted MS/MS Spectrum - 40V, Negative (Annotated) Predicted LC-MS/MS Not Available
Targets
- Kind
- Protein
- Organism
- Humans
- Pharmacological action
- Unknown
- General Function
- G-protein coupled receptor activity
- Specific Function
- Acts as a receptor for kynurenic acid, an intermediate in the tryptophan metabolic pathway. The activity of this receptor is mediated by G-proteins that elicit calcium mobilization and inositol pho...
- Gene Name
- GPR35
- Uniprot ID
- Q9HC97
- Uniprot Name
- G-protein coupled receptor 35
- Molecular Weight
- 34071.89 Da
References
- Zhao P, Sharir H, Kapur A, Cowan A, Geller EB, Adler MW, Seltzman HH, Reggio PH, Heynen-Genel S, Sauer M, Chung TD, Bai Y, Chen W, Caron MG, Barak LS, Abood ME: Targeting of the orphan receptor GPR35 by pamoic acid: a potent activator of extracellular signal-regulated kinase and beta-arrestin2 with antinociceptive activity. Mol Pharmacol. 2010 Oct;78(4):560-8. doi: 10.1124/mol.110.066746. Epub 2010 Jul 22. [Article]
- Kind
- Protein
- Organism
- Humans
- Pharmacological action
- No
- Actions
- AntagonistAgonist
- General Function
- Phosphatidylinositol phospholipase c activity
- Specific Function
- The muscarinic acetylcholine receptor mediates various cellular responses, including inhibition of adenylate cyclase, breakdown of phosphoinositides and modulation of potassium channels through the...
- Gene Name
- CHRM1
- Uniprot ID
- P11229
- Uniprot Name
- Muscarinic acetylcholine receptor M1
- Molecular Weight
- 51420.375 Da
References
- Rayes D, De Rosa MJ, Spitzmaul G, Bouzat C: The anthelmintic pyrantel acts as a low efficacious agonist and an open-channel blocker of mammalian acetylcholine receptors. Neuropharmacology. 2001 Aug;41(2):238-45. [Article]
Enzymes
- Kind
- Protein
- Organism
- Humans
- Pharmacological action
- Unknown
- Actions
- Substrate
- General Function
- Leukotriene-b4 20-monooxygenase activity
- Specific Function
- Catalyzes the omega- and (omega-1)-hydroxylation of various fatty acids such as laurate, myristate and palmitate. Has little activity toward prostaglandins A1 and E1. Oxidizes arachidonic acid to 2...
- Gene Name
- CYP4A11
- Uniprot ID
- Q02928
- Uniprot Name
- Cytochrome P450 4A11
- Molecular Weight
- 59347.31 Da
References
- Li XQ, Bjorkman A, Andersson TB, Gustafsson LL, Masimirembwa CM: Identification of human cytochrome P(450)s that metabolise anti-parasitic drugs and predictions of in vivo drug hepatic clearance from in vitro data. Eur J Clin Pharmacol. 2003 Sep;59(5-6):429-42. Epub 2003 Aug 12. [Article]
Drug created at December 03, 2015 16:51 / Updated at August 09, 2022 10:05