阿朴嗎啡
阿朴嗎啡是一種合成的鴉片類衍生物，但與嗎啡不同，它缺乏顯著的鎮痛作用。在獸醫學中，它被廣泛認為是**犬隻的首選催吐劑**，用於迅速排除誤食的毒物。 * **作用迅速：** 經由腸胃外（靜脈/肌肉注射）或點入結膜囊給藥時，能非常快速地引發嘔吐。 * **物種特異性：** 對犬隻極為有效。由於在貓的療效較差且有潛在的安全疑慮，其在貓的使用具爭議性，通常不建議使用。 * **限制：** 與所有催吐劑一樣，它通常只能清除胃內 40-60%（最多 80%）的內容物。成功催吐並不代表不需要進一步的毒物學監測或治療（例如給予活性碳）。
作用機制: Apomorphine acts as a **non-selective dopamine agonist**. It directly stimulates **D2-dopaminergic receptors** in the **chemoreceptor trigger zone (CRTZ)** located in the area postrema of the medulla oblongata. **Mechanism Pathway:** Apomorphine administration → Crosses the blood-brain barrier → Stimulates D2 receptors in the CRTZ → Activates the central vomiting center → Initiates the emetic reflex. > **Clinical Pearl:** The CRTZ in dogs is highly sensitive to dopamine, making apomorphine highly effective. In contrast, the feline CRTZ is mediated primarily by alpha-2 adrenergic receptors, which is why alpha-2 agonists (like xylazine or dexmedetomidine) are the preferred emetics for cats, while apomorphine is often ineffective.
各物種劑量
- Induction of emesis · 0.03 mg/kg IV or 0.04 mg/kg IM (IV route preferred); alternatively a portion of tablet may be crushed in a syringe, dissolved with few drops of water and administered into the conjunctival sac. After sufficient vomiting occurs, rinse conjunctival sac free of unabsorbed apomorphine. · IV/IM/Topical · Once · IV route preferred.
- Induction of emesis · 0.04 mg/kg IV or 0.08 mg/kg IM or SC · IV/IM/SC · Once
- Induction of emesis · 0.04 mg/kg IV, 0.07 mg/kg IM, or 0.25 mg/kg into the conjunctival sac · IV/IM/Topical · Once
- Induction of emesis · 0.2 mg/kg · SC · single dose · single dose · Authorized dose. Do not repeat if ineffective.
- Induction of emesis · 20-40 μg/kg · IV · single dose · single dose · Non-authorized dose and route but some evidence suggests it is at least as effective.
- Induction of emesis · 0.04 mg/kg IV or 0.08 mg/kg IM or SC · IV/IM/SC · Once · Use of apomorphine in cats is controversial and many recommend not using in this species.
- Induction of emesis · Not recommended · IM · single dose · single dose · Xylazine is a potent emetic in cats and at least as safe.
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
- Rodents and rabbits (unable to vomit or lack stomach wall strength)
- Hypoxia, dyspnea, or shock
- Lack of normal pharyngeal reflexes (risk of aspiration)
- Seizuring, comatose, or severely CNS-depressed patients
- Patients who have already vomited repeatedly
- Ingestion of strong acids, alkalis, or other caustic agents (risk of esophageal/gastric rupture)
- Ingestion of petroleum distillates (unless toxicity risk outweighs aspiration risk)
- Ingestion of strychnine or other CNS stimulants (may precipitate seizures)
- Oral opiate or other CNS depressant (e.g., barbiturates) toxicity
- Hypersensitivity to morphine
不良反應
- Protracted vomiting
- CNS depression (lethargy, sedation)
- CNS stimulation (excitement, restlessness)
- Respiratory depression
- Corneal ulcers (anecdotal, associated with conjunctival administration)
藥物相互作用
- Antidopaminergic drugs (e.g., phenothiazines, metoclopramide) · May negate the emetic effects of apomorphine by blocking dopamine receptors in the CRTZ.
- Ondansetron · May cause severe hypotension; concurrent use is contraindicated in humans.
- Opiates or CNS/Respiratory depressants (e.g., barbiturates) · Additive CNS or respiratory depression may occur.
- Antidopaminergics (e.g., phenothiazines) · May reduce the emetic effects of apomorphine · moderate
- Opiates and CNS depressants · Additive CNS or respiratory depression · major
監測
- CNS status (depression or excitement)
- Respiratory rate and effort
- Heart rate and rhythm
- Vomitus (quantify volume, examine for toxic contents, and save for possible later analysis)
過量
Excessive doses of apomorphine may result in: * Respiratory and/or cardiac depression * CNS stimulation (excitement, seizures) or severe CNS depression * Protracted vomiting **Treatment:** * **Naloxone** may reverse the CNS and respiratory depressant effects of the drug, but it **cannot** be expected to halt the vomiting. * **Atropine** has been suggested to treat severe bradycardias associated with overdose. * If protracted vomiting occurs from conjunctival administration, thoroughly flush the eye with sterile saline.
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。