クロナゼパム

動物種別の用量

投与経路

禁忌

• Hypersensitivity to clonazepam or other benzodiazepines
• Significant liver disease or dysfunction
• Acute narrow-angle glaucoma
• Myasthenia gravis (may exacerbate weakness)
• Marked CNS depression
• Respiratory depression
• Severe muscle weakness
• Hepatic impairment (may worsen hepatic encephalopathy)
• Acute narrow angle glaucoma

有害事象

• Sedation and lethargy
• Ataxia (incoordination)
• Paradoxical excitement, hyperactivity, or vocalization
• Increased salivation
• Gastrointestinal upset (vomiting, diarrhea, constipation)
• Dogs: Rapid tolerance to anticonvulsant effects
• Cats: Polyphagia, potential for acute hepatic necrosis (rare)
• Sedation
• Respiratory suppression (at higher doses)
• Ataxia
• Acute hepatic necrosis (idiosyncratic in cats)
• Tolerance development

薬物相互作用

• Azole Antifungals (itraconazole, ketoconazole) · May increase clonazepam levels by inhibiting its metabolism.
• Cimetidine · May decrease the metabolism of benzodiazepines, increasing their effects.
• CNS Depressants (barbiturates, narcotics, anesthetics) · Additive CNS depression; may cause profound sedation or respiratory depression.
• Erythromycin · May decrease the metabolism of benzodiazepines.
• Phenobarbital · May decrease clonazepam concentrations via hepatic enzyme induction. · moderate
• Phenytoin · May decrease clonazepam concentrations. · moderate
• Propantheline · May decrease clonazepam concentrations.
• Rifampin · May induce hepatic microsomal enzymes and decrease the pharmacologic effects of benzodiazepines.
• Antifungal imidazoles (e.g., Ketoconazole, Itraconazole) · Inhibition of CYP450 enzymes may decrease clonazepam clearance, increasing its plasma levels and risk of toxicity. · moderate
• Other CNS Depressants · Additive sedation and respiratory depression. · major

モニタリング

• Clinical efficacy (seizure frequency, anxiety levels)
• Adverse effects (sedation, ataxia, paradoxical excitement)
• Therapeutic blood levels (reported target: 0.015-0.07 mcg/mL)
• Cats: Baseline and periodic liver function tests
• Degree of sedation and ataxia
• Respiratory rate and effort
• Hepatic function panel (especially in cats)
• Clinical response (seizure frequency, muscle tone, or behavioral changes)

過量投与

Overdoses commonly cause profound **sedation, depression, and ataxia**. - **Paradoxical Reactions:** Some animals may exhibit paradoxical signs such as hyperactivity, disorientation, agitation, and vocalization. Paradoxical excitation can be treated with a mild sedative, such as diphenhydramine. - **Management:** Emesis is generally NOT indicated due to the risk of rapid CNS depression and aspiration. Mild to moderate overdoses can often be monitored at home if the animal is rousable and not showing paradoxical signs. Keep the animal confined and minimize stimulation. - **Severe Toxicity:** Massive overdoses can lead to respiratory depression or hypotension. **Flumazenil** (a specific benzodiazepine antagonist) can be used to reverse severe respiratory or CNS depression. Because flumazenil has a short half-life, multiple doses may be required.