氯二氮平與克利idinium
氯二氮平（Chlordiazepoxide）是一種長效的**苯二氮平類藥物**，主要用於其抗焦慮和輕度鎮靜作用。克利idinium（Clidinium bromide）是一種合成的四級銨**抗蕈毒鹼（抗膽鹼）**藥物，可減少胃腸道蠕動和痙攣。 在獸醫學中，這些藥物偶爾會單獨或合併使用： * **單獨使用氯二氮平**：作為行為障礙的輔助治療，例如狗的噪音恐懼症，或貓的貓際攻擊行為和噴尿問題。 * **氯二氮平 + 克利idinium (Librax®)**：此複方藥物在治療壓力引起的胃腸道疾病（如狗的**大腸激躁症 IBS**）方面具有獨特地位。它能同時處理中樞焦慮成分（透過氯二氮平）和周邊胃腸痙攣（透過克利idinium）。 > **臨床要點**：由於克利idinium是一種四級胺，它不易穿過血腦屏障，因此避免了阿托品（atropine）常見的中樞抗膽鹼副作用。
作用機制: The combination product exerts its effects through two distinct mechanisms targeting the central nervous system and the peripheral gastrointestinal tract: * **Chlordiazepoxide (Anxiolytic/Sedative)**: Binds to the benzodiazepine allosteric site on the **GABA-A receptor** complex in the CNS → enhances the affinity of the receptor for the inhibitory neurotransmitter **gamma-aminobutyric acid (GABA)** → increases the frequency of chloride channel openings → neuronal hyperpolarization. This dampens activity in the limbic system, thalamus, and hypothalamus, producing anxiolytic, muscle relaxant, and anticonvulsant effects. * **Clidinium (Antispasmodic)**: Acts as a competitive antagonist at **muscarinic acetylcholine receptors** (primarily M3 receptors in the gut) → inhibits parasympathetic nerve impulses → significantly reduces gastrointestinal smooth muscle spasms, motility, and gastric acid secretion.
各物種劑量
- As an anxiolytic · 0.5-1 mg/kg · PO · q12-24h · Chlordiazepoxide alone
- Behavior indications (thunderstorm/noise phobias) · 2.2-6.6 mg/kg · PO · as needed · Chlordiazepoxide alone; start low
- Symptomatic treatment of irritable bowel syndrome · 0.1-0.25 mg/kg of clidinium or 1-2 capsules · PO · two times to three times a day · Discontinued in a few days · Using the combination product (e.g., Librax). Give when abdominal pain or diarrhea first noticed or if stressful conditions are encountered.
- Symptomatic treatment of irritable bowel syndrome · 0.44-1.1 mg/kg of clidinium · PO · two to three times a day · 1 day to 2 weeks (some require long-term treatment at 1-2 doses per day) · Using the combination product (e.g., Librax). Use at first signs of cramping or abdominal pain.
劑量為合格獸醫專業人員的臨床參考。請務必對照最新藥品仿單及個別病患確認。
給藥途徑
禁忌症
- Known hypersensitivity to benzodiazepines or antimuscarinics
- Coma, shock, or significant respiratory depression
- Aggressive patients (may disinhibit bite inhibition and worsen aggression)
- Tachycardia secondary to thyrotoxicosis or cardiac insufficiency
- Myocardial ischemia
- Gastrointestinal obstructive disease or paralytic ileus
- Severe ulcerative colitis
- Obstructive uropathy
- Myasthenia gravis
- Known or suspected GI infections (may prolong retention of toxins/pathogens)
不良反應
- Paradoxical CNS excitement or agitation (especially in dogs)
- Variable sedation and lethargy
- Behavioral changes (irritability, aberrant demeanor in cats)
- Potential hepatotoxicity (idiosyncratic hepatic failure reported with oral diazepam in cats; unknown if chlordiazepoxide shares this risk)
- Dry mouth (xerostomia)
- Constipation or dysphagia
- Urinary retention or hesitancy
- Tachycardia (at higher doses) or initial bradycardia
藥物相互作用
- Digoxin · Pharmacologic effects of digoxin may be increased; clidinium may also increase serum levels of slow-dissolving digoxin.
- CNS Depressants (barbiturates, opiates, anesthetics) · Additive CNS depression and sedative effects.
- Probenecid · May interfere with benzodiazepine metabolism in the liver, causing increased or prolonged effects.
- Rifampin · May induce hepatic microsomal enzymes and decrease the pharmacologic effects of benzodiazepines.
- Cimetidine · May decrease the metabolism of chlordiazepoxide, leading to excessive sedation.
- Erythromycin · May decrease the metabolism of chlordiazepoxide, leading to excessive sedation.
- Fluoxetine · May decrease the metabolism of chlordiazepoxide, leading to excessive sedation.
- Isoniazid · May decrease the metabolism of chlordiazepoxide, leading to excessive sedation.
- Ketoconazole · May decrease chlordiazepoxide metabolism. Additionally, increased gastric pH from clidinium may decrease GI absorption of ketoconazole (administer clidinium 2 hours after ketoconazole).
- Metoprolol · May decrease the metabolism of chlordiazepoxide, leading to excessive sedation.
- Propranolol · May decrease the metabolism of chlordiazepoxide, leading to excessive sedation.
監測
- Clinical efficacy (reduction in anxiety, resolution of GI spasms/diarrhea)
- Adverse effects (excessive sedation, paradoxical excitement, anticholinergic signs)
- Baseline and periodic liver function tests in cats (due to idiosyncratic hepatotoxicity risks associated with oral benzodiazepines)
過量
Overdoses of chlordiazepoxide alone are generally limited to significant **CNS depression** (confusion, coma, decreased reflexes). Hypotension, respiratory depression, and cardiac arrest are possible but rare. **Treatment**: * Standard protocols for acute oral toxicity (gastric decontamination, binding agents like activated charcoal). * Supportive systemic measures (fluids, cardiovascular support). * **Flumazenil** may be considered as a specific reversal agent for severe benzodiazepine-induced CNS depression. * Analeptic agents (CNS stimulants like caffeine) are generally not recommended.
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