Methotrexate
別名: Rheumatrex, Trexall, Methotrexate LPF, Matrex, Methotrexate
> **WARNING: CHEMOTHERAPY AGENT** > This medication is highly toxic and can be hazardous to humans if handled improperly. * **Handling Safety:** Always wear disposable gloves when administering tablets, especially if they are crushed or split. If gloves are not used, wash hands thoroughly immediately after handling. Pregnant women or immunocompromised individuals should avoid handling this drug. * **Toxicity Risks:** You must be aware of the possibilities of severe toxicity developing from this drug, including drug-related mortality. * **When to Call the Vet:** Contact your veterinarian immediately if your pet exhibits clinical signs of profound depression, lethargy, abnormal bleeding (including bloody diarrhea, dark tarry stools), bruising, vomiting, or loss of appetite. * **Nursing:** Do not allow pets on this medication to nurse offspring; switch to a milk replacer.
劑量必須由獸醫按你寵物的個別情況決定。切勿在沒有獸醫指導下給予人類藥物或其他寵物的處方藥。
用途
- For susceptible neoplastic diseases (usually as part of a multi-drug protocol)
- For non-suppurative cholangitis/cholangiohepatitis (CCHC) syndrome with fibrosis
- As part of the LMP protocol for maintenance of canine lymphoma
- In combination with other antineoplastics (per protocol)
給藥方式
可能的副作用
- Diarrhea
- Nausea
- Vomiting
- Inappetence (especially in cats)
- GI toxicity (ulcers, mucosal sloughing, stomatitis)
- Hematopoietic toxicity / Myelosuppression (nadir at 4-6 days)
- Hepatopathy
- Renal tubular necrosis
- Alopecia
- Depigmentation
- Pulmonary infiltrates and fibrosis
- CNS toxicity (encephalopathy) if given intrathecally
- Anaphylaxis (rare)
- Myelosuppression (neutropenia, thrombocytopenia, anemia)
注意事項與禁忌
- Preexisting bone marrow depression
- Severe hepatic insufficiency
- Severe renal insufficiency
- Hypersensitivity to the drug
- Pregnancy (Teratogenic/Embryotoxic - FDA Category X)
- Nursing mothers
- Pre-existing severe bone marrow suppression
- Severe renal impairment
- Severe hepatic impairment
- Pregnancy and lactation (teratogenic and embryotoxic)
- Patients with significant third-space fluid accumulations (e.g., ascites, pleural effusion)
- Use with extreme caution in patients susceptible to or with preexisting clinical signs of MTX adverse reactions. **Handling Precautions:** Wear gloves or immediately wash hands after handling. Gloves are particularly important if handling split, broken, or crushed tablets. Preparation of intravenous solutions should ideally be performed in a vertical laminar flow hood to avoid human exposure. Teratogenic and may affect spermatogenesis.
藥物相互作用
- Amiodarone: Prolonged PO administration (>2 weeks) may inhibit MTX metabolism
- Asparaginase: Given concomitantly with MTX may decrease MTX efficacy
- Azathioprine: Potential for increased risk for hepatic toxicity
- Chloramphenicol: May displace MTX from plasma proteins increasing risk for toxicity, but also may reduce MTX absorption and enterohepatic recirculation
- Cisplatin: May have synergistic action with MTX, but alter the renal elimination of MTX
- Cyclosporine: May increase MTX levels
- Folic Acid: May reduce MTX efficacy, but folate deficiency increases MTX toxicity
- Neomycin (oral): May decrease the absorption of oral methotrexate if given concomitantly
- NSAIDs / Salicylates: Severe hematologic and GI toxicity risk; use caution in dogs also on MTX
- Penicillins: May decrease MTX renal elimination
- Probenecid: May inhibit the tubular secretion of MTX and increase its half-life
常見問題
Methotrexate用於寵物有甚麼用途？
> **WARNING: CHEMOTHERAPY AGENT** > This medication is highly toxic and can be hazardous to humans if handled improperly. * **Handling Safety:** Always wear disposable gloves when administering tablets, especially if they are crushed or split. If gloves are not used, wash hands thoroughly immediately after handling. Pregnant women or immunocompromised individuals should avoid handling this drug. * **Toxicity Risks:** You must be aware of the possibilities of severe toxicity developing from this drug, including drug-related mortality. * **When to Call the Vet:** Contact your veterinarian immediately if your pet exhibits clinical signs of profound depression, lethargy, abnormal bleeding (including bloody diarrhea, dark tarry stools), bruising, vomiting, or loss of appetite. * **Nursing:** Do not allow pets on this medication to nurse offspring; switch to a milk replacer.
Methotrexate對我的寵物安全嗎？
劑量必須由獸醫按你寵物的個別情況決定。切勿在沒有獸醫指導下給予人類藥物或其他寵物的處方藥。
本文僅供一般健康教育，不能取代專業獸醫意見。如寵物身體不適，請諮詢獸醫。