イミドカルブ
**イミドカルブ（Imidocarb）**は、主に獣医学においてマダニ媒介性の原虫感染症の治療に使用されるジアミジン系抗原虫薬です。 **主な臨床応用：** - **バベシア症**：犬の犬バベシア（*Babesia canis*）や、馬および羊のバベシア種に対して高い有効性を示します。 - **サイトウゾーン症**：猫の*Cytauxzoon felis*感染症の治療に使用され、多くの場合、包括的な治療プロトコルの一部として用いられます。 - **その他の用途**：エールリヒア、ヘパトゾーン、および猫のヘモプラズマの代替または補助治療として利用されることもあります。 *臨床のポイント*：犬バベシアには非常に有効ですが、ギブソンバベシア（*B. gibsoni*）に対する有効性は一般的に低いです。また、アメリカヘパトゾーンのシスト（嚢子）期を排除することはできません。
作用機序: Imidocarb acts by directly targeting the **nucleic acids** of susceptible protozoal organisms. - It binds to and intercalates with **DNA** → causing the double helix to unwind and denature. - This structural damage → **inhibits cellular repair and replication** → leading to parasite death. - *Mechanistic Note*: As a diamidine derivative, it may also interfere with polyamine synthesis and function, further disrupting the parasite's metabolic pathways.
動物種別の用量
- Cytauxzoon felis · 3-4 mg/kg · IM · repeated 7 days after initial dose · Efficacy not proven. Cholinergic effects can be mitigated by pre-treating with atropine. Must also give supportive therapy (IV fluids, prophylactic heparin, nutritional/nursing care, analgesia, and potentially transfusion).
- Cytauxzoon felis · 5 mg/kg · IM · once and then 14 days later
- Feline hemoplasmosis (Mycoplasma haemofelis, M. haemominutum) · 5 mg/kg · IM, SC · every 14 days · until able to maintain a normal PCV · Alternative for cats intolerant of doxycycline.
- Feline clinical ehrlichiosis or anaplasmosis · 5 mg/kg · IM · every 14 days · for at least 2-4 treatments · Alternative to doxycycline.
- Treatment of large babesial species infection · 2.5 mg/kg · IM · once · 1 dose · Dose based on imidocarb dipropionate. Can improve clinical signs. Alternative agents are preferable for smaller species (e.g., B. felis).
- Babesiosis · 1.2 mg/kg · IM · repeat in 10-14 days
- Equine piroplasmosis (Babesia caballi; Babesia equi) · 2.2 mg/kg · IM · once · Will generally allow clinical signs to subside.
- Equine piroplasmosis (Babesia caballi) · 2 mg/kg · IM · once a day · for 2 days · To eliminate B. caballi.
投与経路
禁忌
- Intravenous (IV) administration
- Patients exposed to cholinesterase-inhibiting drugs
- Patients exposed to pesticides or certain chemicals
有害事象
- Pain and inflammation at the injection site (rarely ulceration)
- Salivation/drooling
- Nasal drip/discharge
- Vomiting (usually brief)
- Panting
- Diarrhea
- Restlessness
- Lacrimation and sweating (horses)
- Severe renal tubular or hepatic necrosis (rare)
- Salivation (drooling)
- Vomiting
- Injection site inflammation (mild to severe, potential ulceration)
- Anaphylactoid reactions (reported in cattle)
薬物相互作用
- Cholinesterase-inhibiting drugs (e.g., pyridostigmine) · Increased risk of severe cholinergic toxicity; concurrent use is contraindicated.
- Pesticides and chemicals · May exacerbate cholinergic adverse effects and toxicity.
- Anticholinesterases · Increased risk of severe cholinergic toxicity · major
モニタリング
- Clinical efficacy (resolution of parasitemia and clinical signs)
- Adverse effect profile (cholinergic signs, injection site reactions)
- Creatine kinase (CK) levels (may be significantly increased post-IM injection)
- Liver and kidney function (especially in cases of suspected overdose or pre-existing disease)
- Resolution of clinical signs of babesiosis (fever, anemia, lethargy)
- Blood smears or PCR to confirm parasite clearance
- Injection site for signs of inflammation, necrosis, or ulceration
- Immediate post-injection monitoring for cholinergic crisis
過量投与
**Acute Toxicity & Overdose Signs:** - **Dogs**: At 1.5X the labeled dose (9.9 mg/kg), dogs exhibited signs of liver injury (mildly elevated liver enzymes), pain/swelling at the injection site, and vomiting. - **General Overdose/Chronic Toxicity**: Presents primarily with severe **cholinergic signs** (vomiting, weakness, lethargy, excessive salivation) or adverse changes in liver, kidney, lung, or intestinal function. - **Horses**: The reported LD-50 is 16 mg/kg. **Treatment:** - **Atropine** or other antimuscarinics may be highly useful to treat the cholinergic signs associated with imidocarb toxicity. - Provide symptomatic and supportive care for organ dysfunction.
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。