イベルメクチン

動物種別の用量

投与経路

禁忌

• Foals less than 4 months old (manufacturer recommendation)
• Puppies less than 6 weeks old
• Breeds susceptible to ABCB1-1Δ (MDR1) mutation at high doses (unless tested normal)
• Chelonians (turtles, tortoises)
• Indigo snakes
• Skinks
• Lactating dairy animals (no milk withdrawal established)
• Females of breeding age (cattle/swine, per label)
• Dogs with the MDR1 (ABCB1) gene mutation (unless using strictly at low heartworm preventative doses)
• Chelonians (turtles and tortoises) - causes fatal flaccid paralysis
• Kittens under 16 weeks of age (for topical ear gel)
• Use of concentrated livestock formulations in small animals

有害事象

• Horses: Ventral midline swelling and pruritus (hypersensitivity to dying Onchocerca microfilariae)
• Dogs: Shock-like reaction (when used as microfilaricide), depression, hypothermia, vomiting
• Dogs (MDR1/Toxicity): Ataxia, lethargy, hypersalivation, mydriasis, tremors, seizures, blindness, coma
• Cats: Agitation, vocalization, anorexia, mydriasis, rear limb paresis, tremors, disorientation, blindness
• Cattle: Paralysis/staggering or salivation/bloat (if Hypoderma bovis larvae are killed in vital areas), injection site swelling
• Birds: Lethargy, anorexia, death (especially in finches and budgerigars)
• Neurotoxicity (ataxia, tremors, mydriasis, blindness, coma, death) - especially in MDR1-mutant dogs
• Hypersalivation
• Vomiting
• Lethargy
• Bradycardia

薬物相互作用

• Benzodiazepines · Effects may be potentiated by ivermectin; concurrent use is not advised.
• Ketamine · Avoid ivermectin in reptiles within 10 days of ketamine administration.
• Spinosad · Increased risk of neurotoxicity; do not use with high extra-label doses of ivermectin. · major
• Amiodarone · P-glycoprotein inhibitor; increases risk of ivermectin CNS toxicity.
• Carvedilol · P-glycoprotein inhibitor; increases risk of ivermectin CNS toxicity.
• Clarithromycin · P-glycoprotein inhibitor; increases risk of ivermectin CNS toxicity.
• Cyclosporine · P-glycoprotein inhibitor; increases risk of ivermectin CNS toxicity. · moderate
• Diltiazem · P-glycoprotein inhibitor; increases risk of ivermectin CNS toxicity.
• Erythromycin · P-glycoprotein inhibitor; increases risk of ivermectin CNS toxicity.
• Itraconazole · P-glycoprotein inhibitor; increases risk of ivermectin CNS toxicity.
• Ketoconazole · Strong P-glycoprotein inhibitor; should never be used with ivermectin in dogs. · moderate
• Quinidine · P-glycoprotein inhibitor; increases risk of ivermectin CNS toxicity.

モニタリング

• Clinical efficacy (resolution of parasites, negative skin scrapes, etc.)
• Adverse effects/toxicity (especially neurologic signs: ataxia, mydriasis, tremors)
• MDR1 (ABCB1) genotype (prior to use in susceptible breeds)
• Neurological signs (ataxia, mydriasis, tremors)
• Resolution of parasitic infection

過量投与

**Clinical Signs of Toxicity:** * **Dogs:** Vomiting, ataxia, lethargy, tachycardia, hypersalivation, mydriasis, tremors, and seizures. In non-sensitive breeds, signs rarely occur at ≤ 1 mg/kg. Mydriasis occurs at 2.5 mg/kg, tremors at 5 mg/kg, severe tremors/ataxia at 10 mg/kg. LD50 is 80 mg/kg. In MDR1-sensitive breeds, severe signs can develop within 4 hours at much lower doses. * **Cats:** Agitation, vocalization, anorexia, mydriasis, rear limb paresis, tremors, disorientation, blindness, head pressing, wall climbing. Margin of safety is narrower in kittens (signs seen at 300 mcg/kg). * **Large Animals:** Horses show visual impairment, depression, ataxia at 2 mg/kg. Cattle show ataxia and listlessness at 8 mg/kg. Swine show lethargy, ataxia, tremors, lateral recumbency at 30 mg/kg. **Treatment:** * **Decontamination:** Emptying the gut should be considered for recent massive oral ingestions. Repeated doses of activated charcoal are advised to interrupt enterohepatic recirculation. * **Supportive Care:** Symptomatic and supportive therapy for CNS, GI, and cardiovascular effects. * **Advanced Therapy:** **Intravenous Lipid Emulsion (IVFE)** therapy has been used successfully to facilitate clearance of ivermectin due to its highly lipophilic nature.