馬羅皮坦
馬羅皮坦（Cerenia®）是一種強效的**神經激肽-1 (NK-1) 受體拮抗劑**，廣泛用於預防和治療犬貓的急性嘔吐及暈車。除了止吐作用外，它還具有**內臟鎮痛**的特性，並能降低全身麻醉劑（如七氟醚）的需求量。
作用機制: Maropitant exerts its effects by acting as a potent and selective antagonist at the **neurokinin-1 (NK-1) receptors** in the central nervous system (specifically the emetic center and chemoreceptor trigger zone). * **Substance P Inhibition**: It competitively binds to NK-1 receptors, blocking the binding of **Substance P**, a key neuropeptide/neurotransmitter involved in the emetic pathway. * **Dual Action**: Because Substance P is the final common pathway for vomiting, maropitant effectively suppresses emesis triggered by both **central** and **peripheral** stimuli. * **Pain Modulation**: Substance P is also heavily involved in nociception; blocking its receptors in the visceral pathways provides significant visceral pain relief.
各物種劑量
- As an antiemetic · 1 mg/kg · SC or PO · Unknown · Based on pharmacokinetic study
- As an antiemetic · 0.5-1 mg/kg · SC · once daily · up to 5 days
- Treatment of vomiting · Dose not specified in text · SC/IV · Not specified · Not specified · Treatment by injection is recommended for frequent vomiting. Very high doses may cause haemolysis.
- Prevention of acute vomiting · 1 mg/kg · SC · q24h · up to 5 consecutive days · Given at least one hour prior to anticipated emetogenic event
- Prevention of acute vomiting · 2 mg/kg · PO · q24h · up to 5 consecutive days · Given at least two hours prior to anticipated emetogenic event
- Treatment of acute vomiting · 1 mg/kg · SC · q24h · up to 5 consecutive days · If a longer duration of therapy is needed, a 48 hour washout period is recommended due to accumulation of the drug.
- Prevention of vomiting due to motion sickness · 8 mg/kg (minimum dose) · PO · q24h · up to 2 consecutive days · Given at least two hours prior to travel. If a longer duration of therapy is needed, a 72 hour washout period is recommended.
- Treatment and prevention of vomiting (including chemotherapy) · Dose not specified in text · PO/SC/IV · Not specified (duration of activity is 24 hours) · Up to 5 days · Repeat treatment at a lower dose may be adequate in some individuals. If longer periods of treatment are required, a 72-hour interval is recommended between courses.
- Motion sickness · Dose not specified in text · PO/SC/IV · Not specified · Up to 2 days · Not all preparations are specifically licensed for this purpose.
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
- Puppies less than 11 weeks old (due to risk of bone marrow hypoplasia)
- Suspected gastrointestinal obstruction
- Suspected gastrointestinal perforation
- Use for longer than 48 hours without a definitive diagnosis
不良反應
- Pre-travel vomiting (especially at higher motion sickness doses)
- Hypersalivation
- Pain or swelling at the subcutaneous injection site
- Diarrhea
- Anorexia
- Localized injection site reactions (cats)
- Transient pain reaction during injection (very common, especially in cats)
- Haemolysis (at very high doses in cats)
藥物相互作用
- Highly protein-bound medications · Use with caution; maropitant is highly protein-bound (99.5%) and could theoretically compete for binding sites, though clinical significance is undetermined.
- Calcium-channel antagonists · Maropitant has an affinity for calcium-channels; concurrent use should be avoided. · major
- Highly protein-bound drugs · Maropitant is highly bound to plasma proteins and may compete with other highly bound drugs, potentially altering free drug concentrations. · moderate
監測
- Clinical efficacy (decreased episodes of vomiting)
- Adverse effects (e.g., injection site pain, hypersalivation)
- Resolution of vomiting
- Liver function (in patients with pre-existing hepatic disease)
- Signs of gastrointestinal obstruction or perforation
過量
Maropitant has a wide margin of safety. * **Dogs**: Tolerance has been confirmed at doses up to 3 times the recommended oral dose (8 mg/kg) for 3 times longer than the maximum duration. * **High-Dose Toxicity (20 mg/kg/day in dogs)**: Can cause emesis, significant body weight loss (8-15%), ECG changes (slight increases in P-R interval, P wave duration, and QRS amplitude), slightly lower serum albumin, and increased adrenal weights. * **Rodent Studies**: Doses up to 30-100 mg/kg PO caused decreased activity, irregular/labored respiration, ataxia, and tremors.
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。