Pyrantel pamoate is a broad-spectrum anthelmintic agent widely used in India for the treatment of intestinal nematode infections. It is a depolarizing neuromuscular blocking agent that causes spastic paralysis of the helminth, leading to its expulsion from the gastrointestinal tract. It is considered a first-line treatment for ascariasis and enterobiasis (pinworm) due to its efficacy, single-dose regimen, and favorable safety profile, especially in pediatric populations.
Adult: For Ascariasis & Hookworm: 11 mg/kg (base) as a single dose (max 1 gram). Typically, 250mg tablet: 4 tablets (1g) as a single dose. For Enterobiasis: Same single dose, repeated after 2 weeks to prevent reinfection.
Note: Administer orally. Can be taken with or without food. Taking with food may reduce GI upset. Tablet can be chewed, crushed, or swallowed whole. For pinworm infection, treat all household members simultaneously to prevent cross-reinfection. Strict hygiene (handwashing, nail trimming, laundering bedding) is crucial.
Pyrantel pamoate acts as a depolarizing neuromuscular blocking agent. It stimulates nicotinic acetylcholine receptors on the body wall of susceptible nematodes, leading to persistent activation. This causes a massive influx of sodium ions, resulting in sustained depolarization of the helminth's muscle cells. The consequent spastic (tetanic) paralysis renders the worm immobile, detaching it from the intestinal mucosa. The paralyzed worm is then expelled from the body by normal peristalsis.
Pregnancy: Category C (US FDA). Animal studies are inconclusive. No well-controlled studies in pregnant women. Use during pregnancy, especially the first trimester, only if the potential benefit justifies the potential risk to the fetus. Often avoided in routine antenatal care unless active infection is diagnosed.
Driving: May cause dizziness or drowsiness in some individuals. Patients should be cautioned about operating machinery or driving if they experience these effects.
| Piperazine | Pharmacological antagonism. Piperazine causes flaccid paralysis, opposing the spastic paralysis of pyrantel. Combined use may reduce efficacy of both. | Major |
| Theophylline | Pyrantel may increase theophylline serum levels, potentially leading to toxicity. Monitor theophylline levels. | Moderate |
| Pyran tel Pamoate | Concurrent use with other anthelmintics like levamisole or metronidazole is generally not recommended without medical supervision. | Moderate |
Same composition (Pyrantel Pamoate (250mg)), different brands: