溴化鉀
**溴化鉀 (KBr)** 是一種抗癲癇藥物，主要作為輔助或替代療法，用於控制犬隻的難治性癲癇，特別是在單獨使用苯巴比妥 (phenobarbital) 效果不佳或有禁忌症時。其半衰期極長，這意味著除非使用負荷劑量 (loading dose)，否則需要數個月才能達到穩定的治療血藥濃度。 > **嚴重警告**：溴化鉀嚴禁使用於貓，因為有引發嚴重且可能致命的嗜酸性支氣管炎的高風險。 **臨床提示：** 由於標準實驗室分析儀器會將溴離子測量為氯離子，服用 KBr 的病患會出現假性高氯血症 (血清氯離子濃度假性升高)。
作用機制: Within the central nervous system, bromide competes with transmembrane **chloride** transport and inhibits **sodium** transport → resulting in membrane hyperpolarization and elevation of the seizure threshold. Bromide also competes with chloride in post-synaptic anion channels following activation by inhibitory neurotransmitters → potentiates the effect of **GABA**. It acts synergistically with other GABA-ergic therapeutic agents (such as phenobarbital).
各物種劑量
- Control of seizures (Maintenance) · 20-40 mg/kg · PO · q24h · Long-term · Initial daily maintenance dose. More frequent dosing is not detrimental but not necessary.
- Control of seizures (5-day Loading Dose) · 200 mg/kg/day divided into 4-6 hour doses · PO · Divided q4-6h · 5 days · After 5 days, decrease to maintenance dose (20-40 mg/kg p.o. q24h). If seizures resolve sooner, decrease to maintenance earlier to reduce adverse effects.
- Control of seizures (Single Loading Dose) · 600-1000 mg/kg · PO · Single dose · Once · Likely to result in excessive sedation, ataxia, and potentially vomiting.
- Control of seizures (Intrarectal Loading) · 100 mg/kg · PR · q4h · 6 doses (over 24 hours) · Total 600 mg/kg over 24 hours. Use liquid bromide (250 mg/ml). Useful if animal is not conscious enough for oral medication.
- Contraindicated · Do not use · PO · N/A · N/A · Causes severe coughing due to eosinophilic bronchitis, which may be fatal.
劑量為持牌獸醫專業人員的臨床參考。請務必對照最新藥品說明書及個別病患確認。
給藥途徑
禁忌症
- Cats (causes severe, potentially fatal eosinophilic bronchitis)
- Dogs with a history of, or predisposition to, pancreatitis
不良反應
- Ataxia
- Sedation
- Somnolence
- Vomiting (especially with high concentration solutions >250 mg/ml)
- Polyphagia
- Polydipsia
- Pancreatitis
- Skin reactions (in animals with pre-existing skin diseases)
- Behavioural changes (irritability, restlessness)
- Transient diarrhoea (with intrarectal loading)
藥物相互作用
- Dietary salt (Sodium chloride) · Increased dietary salt increases renal elimination of bromide, decreasing serum bromide concentrations. · major
- Chloride-containing IV fluids · Increases bromide excretion and lowers serum bromide levels. · major
- Loop diuretics (e.g., furosemide) · Increases bromide excretion and decreases serum bromide concentrations. · moderate
- Phenobarbital · Synergistic GABA-ergic anticonvulsant effects. · minor
監測
- Serum KBr concentrations (Therapeutic range: 0.8-1.5 mg/ml)
- Serum chloride (Note: KBr causes falsely elevated chloride readings on standard chemistry panels)
- Renal function (BUN, Creatinine, USG)
- Signs of excessive sedation, ataxia, or vomiting
- Pancreatic enzymes if clinical signs of pancreatitis develop
過量
Acute bromide toxicity (bromism) presents with profound sedation, ataxia, somnolence, and potentially vomiting. **Treatment of choice:** Intravenous administration of **0.9% NaCl (normal saline)**. The chloride in the saline competes with bromide for renal reabsorption, rapidly accelerating the renal excretion of bromide.
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。