Pyrantel
Identification
- Name
- Pyrantel
- Accession Number
- DB11156
- Description
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.
- Associated Conditions
- Contraindications & Blackbox Warnings
Learn about our commercial Contraindications & Blackbox Warnings data.
Learn More- Pharmacodynamics
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
Learn about our commercial Adverse Effects data.
Learn More- Toxicity
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.
- Affected organisms
- Humans
- 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 Unlock Additional DataAbacavir Abacavir may decrease the excretion rate of Pyrantel which could result in a higher serum level. Acarbose Acarbose 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. Additional Data Available- Extended DescriptionExtended DescriptionAvailable for Purchase
Extended description of the mechanism of action and particular properties of each drug interaction.
Learn more - SeveritySeverityAvailable for Purchase
A severity rating for each drug interaction, from minor to major.
Learn more - Evidence LevelEvidence LevelAvailable for Purchase
A rating for the strength of the evidence supporting each drug interaction.
Learn more - ActionActionAvailable for Purchase
An effect category for each drug interaction. Know how this interaction affects the subject drug.
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- Food Interactions
- No interactions found.
Products
- 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 Unlock Additional DataJaa Pyral 35 Tablet 35mg Tablet Oral Jaapharm Canada Inc. 1989-12-31 Not applicable Canada 
Additional Data Available- Application NumberApplication NumberAvailable for Purchase
A unique ID assigned by the FDA when a product is submitted for approval by the labeller.
Learn more - Product CodeProduct CodeAvailable for Purchase
A governmentally-recognized ID which uniquely identifies the product within its regulatory market.
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- Over the Counter Products
Name Dosage Strength Route Labeller Marketing Start Marketing End Region Image Unlock Additional DataCombantrin Oral Suspension 50mg/ml Suspension Oral Mcneil Consumer Healthcare Division Of Johnson & Johnson Inc 1973-12-31 Not applicable Canada Combantrin Tab 125mg Tablet Oral Mcneil Consumer Healthcare Division Of Johnson & Johnson Inc 1973-12-31 Not applicable Canada CVS Pinworm Treatment Suspension 144 mg/1mL Oral CVS Health 2016-12-15 Not applicable US 
Jaa Pyral 125 Tablet 125mg Tablet Oral Jaapharm Canada Inc. 1998-11-27 Not applicable Canada Jaa Pyral P Oral Paste - 125mg/g Paste Oral Jaapharm Canada Inc. 1995-12-31 Not applicable Canada Jaa Pyral S Suspension 50mg/76 Suspension Oral Jaapharm Canada Inc. 1995-12-31 Not applicable Canada Jamp-pyrantel Pamoate Tablet Oral Jamp Pharma Corporation 2013-12-13 Not applicable Canada Jamp-pyrantel Pamoate Suspension Suspension Oral Jamp Pharma Corporation 2014-03-25 Not applicable Canada Parasitexx Suspension 144 mg/1mL Oral Dannso corp./d.b.a. Essential Products 2017-05-01 Not applicable US Parasitol Suspension 144 mg/1mL Oral Menper Distributors 2013-01-01 Not applicable US Additional Data Available- Application NumberApplication NumberAvailable for Purchase
A unique ID assigned by the FDA when a product is submitted for approval by the labeller.
Learn more - Product CodeProduct CodeAvailable for Purchase
A governmentally-recognized ID which uniquely identifies the product within its regulatory market.
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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)
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. [PubMed:5417856]
- 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. [PubMed:11489460]
- 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. [PubMed:25015542]
- 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. [PubMed:7993990]
- 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. [PubMed:9024887]
- 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. [PubMed:12920490]
- 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
- AHFS Codes
- 08:08.00 — Anthelmintics
- MSDS
- Download (41.8 KB)
Clinical Trials
- Clinical Trials
Phase Status Purpose Conditions Count 4 Completed Treatment Hookworm Infection 1 4 Completed Treatment Infection by Trichuris Trichiura 1 4 Recruiting Treatment Drug Resistance / Helminths Infection 1 Not Available Recruiting Prevention Infection / Malnutrition 1
Pharmacoeconomics
- Manufacturers
- Not Available
- Packagers
- Not Available
- Dosage Forms
Form Route Strength Suspension Oral 250 mg/5ml Tablet, chewable Oral 250 mg Suspension Oral 5 MG/100mL Syrup Oral 5 mg/100l Tablet Oral 250 MG Tablet Oral 734.87 mg Suspension Oral 125 MG/5ML Tablet Oral 719.23 mg Tablet Oral 280.74 mg Tablet Oral Paste Oral Suspension Oral Tablet, chewable Oral 725 mg Tablet, coated Oral 250 mg Tablet Oral 100 mg Suspension Oral 5000 mg Capsule, liquid filled Oral 250 mg Suspension Oral 5 g Tablet, chewable Oral 250 mg/1 Suspension Oral 50 mg/1mL Suspension Oral 144 mg/1mL Tablet Oral 757.577 mg Tablet, coated Oral 100 mg 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 Oral 735.15 MG Tablet Oral 125 mg Tablet, film coated Oral 125 MG Syrup Oral 125 MG/5ML - 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. [PubMed:20826425]
- 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. [PubMed:11489460]
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. [PubMed:12920490]
Drug created on December 03, 2015 09:51 / Updated on January 25, 2021 22:38