Mechanism of Action
From a pharmacological standpoint, Pyrantel is an agent that induces neuromuscular blockade in helminths. The drug causes a blockade of cholinergic neuromuscular transmission in nematodes, leading to persistent spastic paralysis. Immobilized parasites are unable to maintain their position in the intestinal lumen and are eliminated naturally via peristalsis.
Pharmacokinetics and Characteristics
The main pharmacokinetic feature of Pyrantel is that it is minimally absorbed from the gastrointestinal tract and excreted unchanged. Due to minimal systemic absorption, the drug has a low toxicity profile, making it safe for use in pediatric and pregnant patients.
Indications for Use
Pyrantel is a specific antinematodal agent with a narrow spectrum targeted at intestinal helminthiases. Main indications for prescription include:
- Ascariasis;
- Enterobiasis (pinworm infection);
- Ancylostomiasis (hookworm infection);
- Necatoriasis;
- Trichuriasis (whipworm infection).
Side Effects and Contraindications
Despite its low toxicity, potential side effects affecting various organ systems include gastrointestinal distress (nausea, diarrhea), central nervous system disturbances (headache, drowsiness), and allergic manifestations such as skin rash.
Contraindications to the drug include individual hypersensitivity and severe hepatic impairment.
Clinical Application and Administration
In clinical practice, the drug is administered orally. The single dose for adults and older children based on body weight is 0.75 g (equivalent to three 0.25 g tablets or 15 mL of suspension). Tablets must be thoroughly chewed before swallowing. Administration should be performed strictly with meals.