pyrantel

{{Short description|Medication for parasitic worm infections}}

{{Infobox drug

| drug_name =

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| type =

| IUPAC_name = 1-Methyl-2-[(E)-2-(2-thienyl)vinyl]-5,6-dihydro-4H-pyrimidine

| image = Pyrantel skeletal formula.svg

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| image2 = Pyrantel ball-and-stick model from PubChem 708857 optimized.png

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| tradename = Pin-X, Combantrin, others{{cite book| vauthors = Hamilton R |title=Tarascon Pocket Pharmacopoeia 2015 Deluxe Lab-Coat Edition|date=2015|publisher=Jones & Bartlett Learning|isbn=9781284057560|page=54}}

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| pregnancy_US = C

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| routes_of_administration = by mouth

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| legal_US = OTC

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| bioavailability = poorly absorbed

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| CAS_number = 15686-83-6

| CAS_supplemental = {{cascite|correct|??}}

| ATCvet =

| ATC_prefix = P02

| ATC_suffix = CC01

| ATC_supplemental = {{ATCvet|P52|AF02}}

| PubChem = 708857

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| DrugBank = DB11156

| ChemSpiderID = 618121

| UNII = 4QIH0N49E7

| KEGG = D08451

| ChEBI = 8654

| ChEMBL = 1626223

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| C=11 | H=14 | N=2 | S=1

| smiles = CN1CCCN=C1/C=C/c2cccs2

| StdInChI = 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+

| StdInChIKey = YSAUAVHXTIETRK-AATRIKPKSA-N

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| melting_high = 179

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Pyrantel is a medication used to treat a number of parasitic worm infections. This includes ascariasis, hookworm infections, enterobiasis (pinworm infection), trichostrongyliasis, and trichinellosis. It is taken by mouth.{{cite book | title = WHO Model Formulary 2008 | year = 2009 | isbn = 9789241547659 | vauthors = ((World Health Organization)) | veditors = Stuart MC, Kouimtzi M, Hill SR | hdl = 10665/44053 | author-link = World Health Organization | publisher = World Health Organization | hdl-access=free |pages=89, 608 }}

Side effects include nausea, headache, dizziness, trouble sleeping, and rash. A lower dose should be used in people with liver disease. While it does not appear to be harmful during pregnancy, it has not been studied for this use.{{cite web|title=Pyrantel Use During Pregnancy | work =Drugs.com |url= https://www.drugs.com/pregnancy/pyrantel.html |access-date=8 December 2016|url-status=live|archive-url= https://web.archive.org/web/20161220223330/https://www.drugs.com/pregnancy/pyrantel.html |archive-date=20 December 2016}} It is unclear if it is safe for use during breastfeeding. It is in the antihelmintic family of medications. It works by paralyzing worms.{{cite web|title=Pyrantel Pamoate|url=https://www.drugs.com/monograph/pyrantel-pamoate.html|publisher=The American Society of Health-System Pharmacists|access-date=8 December 2016|url-status=live|archive-url=https://web.archive.org/web/20161220223248/https://www.drugs.com/monograph/pyrantel-pamoate.html|archive-date=20 December 2016}}

Pyrantel was initially described in 1965.{{cite book | vauthors = Maddison JE, Page SW, Church DB |title=Small Animal Clinical Pharmacology|date=2008|publisher=Elsevier Health Sciences|isbn=978-0702028588|page=209|url=https://books.google.com/books?id=RpsROVqemk8C&pg=PA209|language=en|url-status=live|archive-url=https://web.archive.org/web/20161220080719/https://books.google.ca/books?id=RpsROVqemk8C&pg=PA209|archive-date=2016-12-20}} It is on the World Health Organization's List of Essential Medicines.{{cite book | vauthors = ((World Health Organization)) | title = World Health Organization model list of essential medicines: 21st list 2019 | year = 2019 | hdl = 10665/325771 | author-link = World Health Organization | publisher = World Health Organization | location = Geneva | id = WHO/MVP/EMP/IAU/2019.06. License: CC BY-NC-SA 3.0 IGO | hdl-access=free }} Pyrantel is available as a generic medication. It may also be used to treat worms in a number of other animals.

Pregnancy and breastfeeding

Pyrantel pamoate is considered a pregnancy category C drug for use during pregnancy for humans, but is in category A for canines and felines. Pyrantel is considered safe to use in nursing animals.{{cite book | vauthors = Plumb DC | title = Plumb's veterinary drug handbook | publisher = PharmaVet | location = Stockholm, Wis | year = 2005 | isbn = 978-0-8138-0518-4 }}

Mechanism of action

Pyrantel pamoate acts as a depolarizing neuromuscular blocking agent, thereby causing sudden contraction, followed by paralysis, of the helminths. This has the result of causing the worm to "lose its grip" on the intestinal wall and be passed out of the system by natural process. Since Pyrantel is poorly absorbed by the host's intestine, the host is unaffected by the small dosage of medication used. Spastic (tetanic) paralyzing agents, in particular pyrantel pamoate, may induce complete intestinal obstruction in a heavy worm load.{{cite journal | vauthors = Salman AB | title = Management of intestinal obstruction caused by ascariasis | journal = Journal of Pediatric Surgery | volume = 32 | issue = 4 | pages = 585–587 | date = April 1997 | pmid = 9126759 | doi = 10.1016/S0022-3468(97)90712-0 }} This obstruction is usually in the form of a worm impaction and happens when a very small, but heavily parasitized animal is treated and tries to pass a large number of dislodged worms at once. Worms usually pass in normal stool or with diarrhea, straining, and occasional vomiting.

Names

There are a number of brands, including "Reese's Pinworm Medicine", "Pin-X", "Pin-Rid", "PYRANTRIN", "COMBANTRIN", "Anthel", "Helmintox", "Helmex", "Strongid", Konvermex, and Drontal Cat.

References

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