pyrantel pamoate

Action and Spectrum

Actions and Spectrum: 

Action: 

Neuromuscular Blockade: 

pyrantel pamoate acts on the neuromuscular system of the parasites, particularly nematodes. It inhibits cholinesterase, an enzyme responsible for breaking down acetylcholine (a neurotransmitter), leading to the accumulation of acetylcholine at neuromuscular junctions. This causes sustained muscle contractions and paralysis in the parasites, ultimately leading to their detachment from the intestinal walls. 

Spectrum: 

Enterobius vermicularis (Pinworm): pyrantel pamoate is commonly used to treat pinworm infections, one of the most prevalent intestinal worm infections worldwide. 

Ascaris lumbricoides (Roundworm): This medication is also effective against roundworm infections, which can lead to abdominal discomfort and other symptoms. 

Drug Interaction

Adverse Reaction

Frequency not defined  

Weakness 

Elevated LFTs 

Tenesmus 

Diarrhea 

Abdominal cramps 

Vomiting 

Nausea 

Anorexia 

Rash 

Headache 

Insomnia 

Drowsiness 

Dizziness 

Black Box Warning

Black Box Warning:  

None

Contraindication / Caution

Contraindication/Caution:  

Hypersensitivity: Individuals who have a known hypersensitivity or allergy to pyrantel pamoate or any of its components should avoid using this medication. 

Pregnancy: pyrantel pamoate should be used with caution during pregnancy, especially during the first trimester. It is important to have a conversation with a medical professional to thoroughly explore the potential advantages and disadvantages. 

Breastfeeding: Prior to utilizing pyrantel pamoate during breastfeeding, it is advised to seek guidance from a healthcare professional. 

Severe Liver Dysfunction: Patients with severe liver dysfunction may experience altered metabolism and excretion of pyrantel pamoate, potentially leading to increased drug levels in the body. A healthcare provider should evaluate the risks and benefits before prescribing this medication. 

Neurological Disorders: pyrantel pamoate may have neuromuscular effects. People afflicted by specific neurological conditions, like myasthenia gravis, must exercise care when utilizing this medication and should do so under the supervision of a medical expert. 

Gastrointestinal Obstruction: pyrantel pamoate works by paralyzing worms, and in cases of severe gastrointestinal obstruction, there may be an increased risk of complications. Use of this medication in such cases should be avoided. 

Pregnancy / Lactation

Pregnancy warnings:     

Pregnancy category: C 

Lactation: Excreted into human milk is unknown 

Pregnancy Categories:         

Category A: Studies that were well-controlled and met expectations revealed no risk to the fetus in either the first or second trimester. 

Category B: There were a lack of studies on pregnant women and no evidence of risk to the fetus in animal experiments.   

Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.    

Category D: adequate data with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.   

Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women.    

Category N: There is no data available for the drug under this category

Pharmacology

Pharmacology:  

pyrantel pamoate is an anthelmintic medication primarily used to treat parasitic worm infections. 

Pharmacodynamics:  

pyrantel pamoate primarily acts as a depolarizing neuromuscular blocking agent in nematode parasites. It causes a sustained depolarization of the worm’s neuromuscular junction, leading to a loss of motor coordination and paralysis. This paralysis makes it easier for the host’s natural peristaltic movements to expel the worms from the gastrointestinal tract.   

Pharmacokinetics: 

Absorption 

pyrantel pamoate is an anthelmintic drug used to treat intestinal worm infections. It is administered orally and is well-absorbed from the gastrointestinal tract. The absorption may vary based on factors such as individual metabolism, presence of food, and formulation. 

Distribution 

After absorption, pyrantel pamoate is distributed throughout the body. It is primarily distributed to the gastrointestinal tract, where it exerts its anthelmintic effects against various parasitic worms. The drug may also be distributed to other tissues, but its specific tissue distribution information is limited. 

Metabolism 

pyrantel pamoate undergoes minimal metabolism in the body. It is primarily excreted unchanged or in its active form. The drug’s metabolism is not a significant factor in its overall pharmacokinetics. 

Excretion and Elimination 

The primary route of excretion for pyrantel pamoate is through the feces. A small portion of the drug may be excreted in the urine. The unchanged drug and its metabolites are eliminated from the body within a relatively short period. 

Adminstartion

Administration:  

The administration is by oral route. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: pyrantel pamoate 

Why do we use pyrantel pamoate?  

Pinworm Infections (Enterobiasis): pyrantel pamoate is commonly prescribed to treat pinworm infections caused by Enterobius vermicularis. Pinworms are an intestinal parasite that primarily affects children and can cause itching and discomfort around the anus. 

Hookworm Infections: pyrantel pamoate can also be used to treat hookworm infections caused by species like Ancylostoma duodenale and Necator americanus. These parasites adhere to the lining of the intestines, leading to symptoms such as stomach discomfort, low red blood cell count, and exhaustion. 

Roundworm Infections (Ascariasis): Ascariasis is caused by the roundworm Ascaris lumbricoides. pyrantel pamoate can be used to treat these infections, which may cause symptoms such as abdominal pain, vomiting, and diarrhea. 

Other Parasitic Infections: pyrantel pamoate may also be used to treat other intestinal parasitic infections caused by various types of roundworms.