パレゴリック（カンフルアヘンチンキ）
パレゴリックは、獣医療において下痢の対症療法として時折使用されるオピオイド系消化管運動調節薬です。 **主な臨床的ポイント：** * **成分：** 5 mLあたり2 mgの無水モルヒネ当量を含み、アニス油、グリセリン、安息香酸、カンフル、アルコールを含有します。 * **規制状況：** スケジュールIII（C-III）の規制薬物です。 * **重要な警告：** パレゴリックをアヘンチンキ（Opium tincture）と**絶対に**混同しないでください。アヘンチンキは5 mLあたり50 mgの無水モルヒネを含み、パレゴリックの**25倍の効力**があります。取り違えると致命的な過剰投与を引き起こす可能性があります。 * **動物種に関する注意：** 猫では逆説的な中枢神経興奮を引き起こすリスクがあるため、使用には議論があります。馬や感染性下痢の可能性がある動物では、オピオイドが病原体の排除を遅らせ、症状を悪化させる可能性があります。
作用機序: Paregoric exerts its antidiarrheal effects primarily through the action of morphine on **mu-opioid receptors** in the gastrointestinal tract. * **Motility Inhibition:** Binding to enteric opioid receptors decreases the release of acetylcholine → inhibits excessive GI propulsion and peristalsis, increasing intestinal transit time. * **Secretion Reduction:** Decreases intestinal secretion induced by cholera toxin, prostaglandin E2, and calcium-mediated (non-cyclic AMP/GMP mediated) diarrheas. * **Absorption:** Prolonged transit time allows for enhanced mucosal absorption of water and electrolytes, solidifying the stool.
動物種別の用量
- Maldigestion, malabsorption, anti-diarrheal · 0.05-0.06 mg/kg PO two to three times daily · PO · BID to TID · Use is controversial; this species may react with excitatory behavior.
- Antidiarrheal · 15-30 mL PO · PO · Dose for calves.
- Antidiarrheal · 15-30 mL PO (Foals); 15-60 mL PO (Adults) · PO · May have a detrimental effect in acute/bacterial diarrhea by delaying microbe clearance.
- Acute colitis · 0.06 mg/kg PO three times daily · PO · TID
- Maldigestion; malabsorption; antidiarrheal · 0.05-0.06 mg/kg PO two to three times daily · PO · BID to TID
- Antidiarrheal · 0.05-0.06 mg/kg PO q12h · PO · q12h
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
- Known hypersensitivity to narcotic analgesics
- Patients receiving monoamine oxidase inhibitors (MAOIs)
- Diarrhea caused by toxic ingestion (until the toxin is eliminated from the GI tract)
有害事象
- Dogs: Constipation, bloat, sedation, paralytic ileus, toxic megacolon, pancreatitis, CNS effects
- Cats: Excitatory behavior (controversial use)
- Horses: Delayed clearance of GI microbes, prolonged febrile state
薬物相互作用
- CNS Depressants (anesthetics, antihistamines, phenothiazines, barbiturates, tranquilizers, alcohol) · May cause increased CNS or respiratory depression when used concurrently.
- Monoamine Oxidase Inhibitors (MAOIs, e.g., amitraz, selegiline) · Contraindicated. Opiates should not be used for at least 14 days after receiving MAOIs due to the risk of severe, potentially fatal reactions.
モニタリング
- Clinical efficacy (resolution of diarrhea)
- Fluid and electrolyte status (especially in severe diarrhea)
- CNS effects (sedation in dogs, excitation in cats), particularly if using high dosages
過量投与
Acute overdosage of opiate antidiarrheals can result in severe **CNS, cardiovascular, gastrointestinal, or respiratory toxicity**. * Because opiates significantly reduce GI motility, absorption of the drug from the GI tract may be delayed and prolonged, leading to a sustained toxic effect. * **Treatment:** Naloxone is the specific reversal agent and may be necessary to reverse opiate-induced respiratory depression and CNS effects. Supportive care is essential.
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。