茶苯海明 (苯海拉明複合物)
茶苯海明是一種第一代**H1受體拮抗劑**，以人類品牌藥物Dramamine®（暈車藥）廣為人知。它是由**苯海拉明**（約54%）和**8-氯茶鹼**（約46%，一種溫和的興奮劑，用於抵消抗組織胺的鎮靜作用）組成的鹽類複合物。 在獸醫學中，它主要利用其**止吐**特性來預防和治療犬貓的**暈車/暈動症**。 **臨床要點：** * 因為組織胺被認為不是引起貓咪嘔吐的主要介質，其他止吐藥（如maropitant、prochlorperazine）對貓咪暈車可能更有效。 * 它常被視為「半強度的苯海拉明」，可用於任何需要H1受體阻斷劑的情況。 * 它可作為貓胰臟炎的輔助治療，以減少組織胺介導的微血管通透性增加。
作用機制: Dimenhydrinate exhibits antihistaminic (H1), antiemetic, anticholinergic, CNS depressant, and local anesthetic effects, primarily driven by the **diphenhydramine** moiety. * **H1-Receptor Antagonism**: Competitively blocks histamine at **H1 receptors** → prevents histamine-mediated responses in the GI tract, blood vessels, and respiratory tract. * **Antiemetic/Vestibular Effect**: Blocks **muscarinic acetylcholine receptors** → inhibits acetylcholine stimulation of the vestibular and reticular systems → reduces motion sickness. * **Pancreatitis Application**: H1 blockade → reduces histamine-mediated increases in microvasculature permeability → potentially limits hemorrhagic necrosis in feline pancreatitis.
各物種劑量
- Prevention and treatment of motion sickness/vomiting · 8 mg/kg · PO · q8h
- Prevention and treatment of motion sickness/vomiting · 4-8 mg/kg · PO · q8h
- Antihistamine · 4 mg per cat · PO · q8h
- Adjunctive treatment of pancreatitis · 8 mg/kg · PO · q8h
- Prevention and treatment of motion sickness (antiemetic) · 4-8 mg/kg · PO · three times daily
- Prevention and treatment of motion sickness · 4-8 mg/kg · PO · q8h
- Antihistamine · 4-8 mg/kg · PO · q8-12h
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
- Hypersensitivity to dimenhydrinate or other antihistamines in its class
- Angle closure glaucoma (use with caution)
- Prostatic hypertrophy (use with caution)
- Pyloroduodenal or bladder neck obstruction (use with caution)
- COPD if mucosal secretions are a problem (use with caution)
- Hyperthyroidism, seizure disorders, cardiovascular disease, or hypertension (use with caution)
不良反應
- CNS depression (lethargy, somnolence)
- Anticholinergic effects (dry mouth, urinary retention)
- GI effects (diarrhea, vomiting, anorexia - less common)
藥物相互作用
- Anticholinergic drugs (e.g., tricyclic antidepressants) · May potentiate the anticholinergic effects of other anticholinergic drugs.
- CNS Depressant Drugs · Increased sedation can occur if combined with other CNS depressants.
- Ototoxic Drugs (e.g., aminoglycosides) · May mask the clinical signs of ototoxicity; use with caution when administering concomitantly.
監測
- Clinical efficacy (reduction in vomiting/motion sickness)
- Adverse effects (sedation, anticholinergic signs such as dry mouth or urinary retention)
過量
Overdosage may cause **CNS stimulation** (excitement to seizures) or **depression** (lethargy to coma), anticholinergic effects, respiratory depression, and death. **Treatment:** * Empty the gut if ingestion was oral. Induce emesis if the patient is alert and CNS status is stable. * Administration of a saline cathartic and/or activated charcoal may be given after emesis or gastric lavage. * Symptomatic and supportive therapies. * **Phenytoin (IV)** is recommended in the treatment of seizures caused by antihistamine overdose in humans; use of barbiturates and diazepam are avoided.
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。