ロペラミド

動物種別の用量

投与経路

禁忌

• Dogs tested positive for the ABCB1-1Δ (MDR1) mutation
• Untested dogs of herding breeds susceptible to the MDR1 mutation
• Diarrhea caused by toxic ingestion (until the toxin is eliminated)
• Known hypersensitivity to narcotic analgesics
• Infectious enteritis (relative contraindication, as decreased motility can delay pathogen clearance)
• Intestinal obstruction
• Dogs likely to be ivermectin-sensitive (MDR1/ABCB1 mutation, e.g., Collies, Australian Shepherds)
• Infectious enteritis (where decreased motility may delay pathogen clearance)
• Toxigenic diarrhea

有害事象

• Constipation
• Bloat
• Sedation
• Paralytic ileus
• Toxic megacolon
• Pancreatitis
• CNS depression (especially in MDR1-mutant dogs)
• Excitatory behavior (cats)
• Excitability (especially in cats)
• Profound sedation and ataxia (in MDR1 mutant dogs)

薬物相互作用

• Amiodarone · Inhibits P-glycoprotein (P-gp), which may increase loperamide plasma concentrations and risk of CNS toxicity.
• Carvedilol · Inhibits P-glycoprotein (P-gp), which may increase loperamide plasma concentrations and risk of CNS toxicity.
• Erythromycin · Inhibits P-glycoprotein (P-gp), which may increase loperamide plasma concentrations and risk of CNS toxicity.
• Ketoconazole · Inhibits P-glycoprotein (P-gp), which may increase loperamide plasma concentrations and risk of CNS toxicity.
• Itraconazole · Inhibits P-glycoprotein (P-gp), which may increase loperamide plasma concentrations and risk of CNS toxicity.
• Quinidine · Inhibits P-glycoprotein (P-gp), which may increase loperamide plasma concentrations and risk of CNS toxicity.
• Tamoxifen · Inhibits P-glycoprotein (P-gp), which may increase loperamide plasma concentrations and risk of CNS toxicity.
• Verapamil · Inhibits P-glycoprotein (P-gp), which may increase loperamide plasma concentrations and risk of CNS toxicity.
• Other antimotility drugs · Additive reduction in GI motility, increasing risk of ileus · moderate
• P-glycoprotein inhibitors (e.g., ketoconazole, cyclosporine, spinosad) · May increase CNS penetration of loperamide, leading to neurotoxicity · major
• CNS depressants · Additive sedation if loperamide crosses the blood-brain barrier · moderate

モニタリング

• Clinical efficacy (resolution of diarrhea)
• Fluid and electrolyte status (especially in severe diarrhea)
• CNS effects (sedation, ataxia, depression), particularly if using high dosages or in susceptible breeds
• Fecal consistency and frequency
• Signs of constipation or paralytic ileus
• Neurological status (watch for sedation or ataxia, especially in at-risk breeds)
• Hydration status

過量投与

In dog toxicity studies, doses of 1.25-5 mg/kg/day produced **vomiting, depression, severe salivation, and weight loss**. > **CRITICAL WARNING:** Breeds with a defective MDR1 (ABCB1-1Δ) gene are profoundly more sensitive to CNS depression with loperamide than other breeds and have shown clinical signs of toxicity at doses as low as **0.06 mg/kg**. Common clinical signs of overdose include diarrhea, vomiting, lethargy, anorexia, weakness, and hypersalivation. **Treatment:** * Follow standard GI decontamination protocols. * **Avoid apomorphine** for emesis, as it can have additive CNS or respiratory depressant effects. * **Naloxone** may be used to treat severe CNS/respiratory depression; higher than usual doses of naloxone may be required to reverse loperamide toxicity.