丁螺環酮
丁螺環酮 (Buspirone) 是一種屬於氮雜螺環酮 (azapirone) 類的非苯二氮平類抗焦慮藥物。主要用於獸醫學中治療犬貓的廣泛性焦慮、輕度恐懼症以及貓的噴尿標記行為。 與苯二氮平類藥物不同，它不具備鎮靜、肌肉鬆弛或抗癲癇作用，因此非常適合長期行為控制且不會造成明顯的認知或精神運動功能障礙。 **臨床要點：** * **延遲起效：** 此藥物需要長期給藥（通常 1 至 4 週）以改變受體密度並達到完全的臨床療效。 * **不適用於急性恐慌：** 由於起效緩慢，它不適合也無法作為急性、情境恐慌（例如立即的雷雨恐懼或急性分離焦慮發作）的單一療法。 * **社交動態：** 它對於與社交互動相關的焦慮特別有用，且在多貓家庭中的效果可能比單貓家庭更好。
作用機制: Buspirone is an anxioselective agent that acts primarily as a partial agonist at **serotonin (5-HT1A) receptors** and as an agonist/antagonist at presynaptic **dopamine (D2) receptors** in the CNS. * **Serotonin Pathway:** By binding to 5-HT1A autoreceptors → it slows the neuronal firing rate → decreasing the depletion of serotonin stores and modulating serotonergic tone over time. * **Receptor Specificity:** It does **not** share mechanisms with benzodiazepines; it has no significant affinity for benzodiazepine receptors and does not affect GABA binding.
各物種劑量
- Adjunctive treatment of low-grade anxieties/fears, spraying, overgrooming · 0.5-1 mg/kg PO q8-12h; 2.5-5 mg (total dose) per cat PO q8-12h · PO · q8-12h · 6-8 weeks · some cats do well on once daily dosing
- Adjunctive treatment of low-grade anxieties/fears, spraying, overgrooming · 2.5-5 mg (total dose) PO once a day to 3 times a day · PO · q8-24h
- Urine marking · 2.5-7.5 mg (total dose) per cat PO q12h · PO · q12h
- Adjunctive treatment of low-grade anxieties/fears, spraying, overgrooming · 0.5-1 mg/kg PO q12h; 2.5-7.5 mg (total dose) per cat PO q12h · PO · q12h
- Social phobias, panic disorders · 0.5-1 mg/kg PO q8-12h · PO · q8-12h · most useful in social phobias; may also be useful for panic disorders
- Low-grade anxieties and fears · 1 mg/kg PO q8-24h (mild anxiety); 2.5-10 mg (total dose) per dog PO q8-24h (mild anxiety); 10-15 mg per dog PO q8-12h (more severe anxiety, thunderstorm phobia) · PO · q8-24h or q8-12h
- Low-grade anxieties and fears · 1-2 mg/kg PO q12h; 5-15 mg (total dose) per dog PO q8-12h · PO · q8-12h or q12h
- Low-grade anxieties and fears · 5-10 mg (total dose) PO q8-12h · PO · q8-12h
- Global anxiety · 0.5-2 mg/kg PO q8-12h · PO · q8-12h · may take 2-4 weeks until effect
給藥途徑
禁忌症
- Severe hepatic disease (use with caution)
- Severe renal disease (use with caution)
- Aggressive animals (may reduce disinhibition)
- Working dogs (use with caution despite low sedation)
- Acute situational anxieties (as sole therapy)
不良反應
- Bradycardia
- Gastrointestinal disturbances
- Stereotypic behaviors
- Increased affection (cats)
- Paradoxical aggression/turning on attackers (previously timid cats)
- Dizziness (humans)
- Headache (humans)
- Nausea/anorexia (humans)
- Restlessness (humans)
- Tachycardia (rare)
藥物相互作用
- Tricyclic or SSRI agents · May be used in combination, but dosage reductions may be necessary to minimize adverse effects
- CNS Depressants · Potentially could cause increased CNS depression
- Diltiazem · May cause increased buspirone plasma levels and adverse effects
- Erythromycin · May cause increased buspirone plasma levels and adverse effects
- Grapefruit juice (powder) · May cause increased buspirone plasma levels and adverse effects
- Ketoconazole, Itraconazole · May cause increased buspirone plasma levels and adverse effects
- Monoamine Oxidase Inhibitors (e.g., selegiline, amitraz) · Use with buspirone is not recommended because dangerous hypertension may occur
- Rifampin · May cause decreased buspirone plasma levels
- Trazodone · Use with buspirone may cause increased ALT
- Verapamil · May cause increased buspirone plasma levels
監測
- Efficacy (reduction in anxiety, spraying, or fear behaviors)
- Adverse effect profiles (GI upset, behavioral changes)
過量
Limited information is available in veterinary species. The oral LD50 in dogs is 586 mg/kg. **Clinical Signs of Overdose:** * Vomiting * Dizziness * Drowsiness * Miosis (constricted pupils) * Gastric distention **Treatment:** Standard overdose protocols (e.g., decontamination, supportive care) should be followed after ingestion has been determined.
VetSheet 藥物參考供持牌獸醫專業人員作臨床決策輔助之用,不能取代專業判斷或廠方最新藥品說明書。