ピランテル
**ピランテル**は、獣医療において消化管内線虫、特に回虫や鉤虫の駆除に広く使用される広域駆虫薬です。鞭虫への有効性を高めるために**フェバンテル**や**オキサンテル**と、あるいは条虫を標的とするためにプラジクアンテルと頻繁に配合されます。 > **臨床のポイント:** ピランテルは消化管からの吸収が非常に悪いです。この薬物動態学的特性は、標的となる寄生虫が存在する腸管内で高濃度を維持できる一方で、全身への曝露を最小限に抑え、宿主に対する高い安全性に寄与するため、非常に有益です。
作用機序: Pyrantel acts as a **depolarizing neuromuscular blocking agent** in susceptible parasites. It functions as a **cholinergic agonist** at the nicotinic acetylcholine receptors of the nematode → causes continuous depolarization of the parasite's muscle cell membrane → results in **spastic paralysis** of the worm. The paralyzed parasites lose their attachment to the intestinal wall and are subsequently expelled from the host's gastrointestinal tract via normal peristalsis.
動物種別の用量
- Control of Toxocara canis, Toxascaris leonina, Trichuris vulpis, Uncinaria stenocephala, and Ancylostoma caninum · 5 mg/kg pyrantel + 15 mg/kg febantel or 20 mg/kg oxantel · PO · repeat as required · Single dose, repeat as required · Often administered as a combination product.
- Control of susceptible gastrointestinal nematodes · 57.5 mg/kg pyrantel embonate · PO · repeat as required · Single dose, repeat as required · Equivalent to approximately 20 mg/kg pyrantel base.
用量は獣医療従事者向けの臨床リファレンスです。必ず最新の添付文書と個々の患者で確認してください。
投与経路
禁忌
- Puppies < 2 months of age
- Puppies < 1 kg body weight
- Pregnant animals (safety not established)
- Lactating animals (safety not established)
有害事象
- Vomiting
- Diarrhoea
薬物相互作用
- Febantel · Synergistic effect against whipworms · null
- Oxantel · Synergistic effect against whipworms · null
- Piperazine · Antagonistic mechanisms of action (piperazine causes flaccid paralysis, pyrantel causes spastic paralysis) · major
- Levamisole · Similar mechanism of action; concurrent use increases the risk of cholinergic toxicity · major
- Cholinesterase inhibitors · Increased risk of cholinergic toxicity · major
モニタリング
- Resolution of clinical signs (e.g., diarrhea, poor weight gain)
- Fecal flotation/egg counts to confirm parasite clearance
過量投与
Due to its poor gastrointestinal absorption, pyrantel has a wide margin of safety. Massive overdosage may result in systemic cholinergic signs, including **salivation, vomiting, tremors, ataxia, and dyspnea**. Treatment is supportive and symptomatic.
VetSheet の薬剤リファレンスは、獣医療従事者向けの臨床意思決定支援を目的としており、専門的判断やメーカーの最新添付文書に代わるものではありません。