クエン酸ジエチルカルバマジン
**クエン酸ジエチルカルバマジン (DEC)** はピペラジン誘導体の駆虫薬であり、かつては犬の毎日のフィラリア予防における標準的な薬剤でした。 * **現状**: 現在では、月に1回投与するマクロライド系薬剤（イベルメクチン、ミルベマイシンなど）にほぼ取って代わられています。米国では獣医用経口剤は市販されていません。 * **適応症**: 犬のフィラリア（*D. immitis*）予防および回虫症の治療薬としてFDAに承認されています。フェレット、動物園の動物、および牛や羊の寄生虫性気管支炎（英国）にも使用されます。 * **臨床のポイント**: 新しい月1回の予防薬とは異なり、DECは**毎日**投与する必要があるため、飼い主のコンプライアンス維持が歴史的な課題でした。
作用機序: The exact mechanism of DEC is not completely understood, but it exhibits both direct paralytic and host-dependent immunomodulatory effects: * **Direct Paralysis**: DEC acts as an agonist at **nicotinic acetylcholine receptors (nAChRs)** on the nematode somatic muscle → Depolarization of the muscle membrane → **Spastic paralysis** of the parasite. * **Immunomodulation**: DEC alters the parasite's surface membrane (interfering with arachidonic acid metabolism) → Exposes hidden antigens → Enhances host immune system clearance of microfilariae.
動物種別の用量
- Treatment of ascarids · 55-110 mg/kg PO · PO · Once · Single dose
- Heartworm prophylaxis · 5.5 mg/kg PO once a day · PO · q24h · Continuous
- Treatment of early stages of Dictyocaulus viviparous infestations · 22 mg/kg IM for 3 successive days; or 44 mg/kg IM once. · IM · q24h or Once · 3 days or Single dose · DEC is available in an injectable dosage form containing 400 mg/mL in the U.K., no FDA-approved injectable form is available in the U.S.A.
- Heartworm prophylaxis · 6.6 mg/kg PO once a day preceding infection and for 60 days following last exposure to mosquitoes. · PO · q24h · 60 days post-exposure · In dogs that become microfilaremic while on DEC, may continue, but do not interrupt daily DEC therapy.
- Heartworm prophylaxis · 6.6 mg/kg PO daily from beginning of mosquito season and for two months thereafter. · PO · q24h · Seasonal + 2 months · Should be given year-round in areas where mosquitoes are active throughout the year. Re-examine 3 months after starting therapy and at 6-month intervals for microfilaria.
- Heartworm prophylaxis · 2.5-3 mg/kg PO daily; begin prior to mosquito season · PO · q24h · Continuous
- Heartworm prophylaxis · 5-7 mg/kg PO daily. Begin before infection is likely and continue 60 days after mosquito season. · PO · q24h · Seasonal + 60 days · Some areas will require year-round treatment.
投与経路
禁忌
- Dogs with circulating microfilaria (due to risk of severe shock-like reaction)
有害事象
- Vomiting
- Diarrhea
- Fixed drug eruptions (rare)
- Severe anaphylactoid reaction (in microfilaremic dogs)
- Hepatic injury (reported in cats)
薬物相互作用
- Pyrantel · Theoretical enhancement of toxic effects due to shared nicotine-like mechanism of action; use with intensified monitoring.
- Morantel · Theoretical enhancement of toxic effects due to shared nicotine-like mechanism of action; use with intensified monitoring.
- Levamisole · Theoretical enhancement of toxic effects due to shared nicotine-like mechanism of action; use with intensified monitoring.
モニタリング
- Microfilaria status (prior to and during heartworm prophylaxis)
- Clinical efficacy (when used as an anthelmintic)
過量投与
DEC is considered a relatively non-toxic compound with a wide margin of safety. * **Clinical Signs**: Large overdoses generally result in self-limiting vomiting or CNS depression. * **Management**: For very large, recent ingestions, consider GI decontamination (inducement of vomiting, activated charcoal, cathartics). If clinical signs occur, provide supportive care (e.g., IV fluids).
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。