奧沙拉秦鈉
奧沙拉秦鈉是一種局部作用的胃腸道抗發炎藥物，主要用於獸醫學中治療犬隻的**慢性結腸炎**。 它可作為對**柳氮磺胺吡啶 (sulfasalazine)** 無效或無法耐受（通常是因為磺胺基團引起乾眼症等副作用）的病患的替代療法。在結構上，它是一種前驅藥，由兩個**5-氨基水楊酸 (5-ASA, mesalamine)** 分子透過偶氮鍵連接而成。由於它缺乏柳氮磺胺吡啶中的磺胺吡啶基團，因此引發免疫介導副作用的風險通常較低，但偶爾仍可能發生淚液分泌減少的問題。
作用機制: Olsalazine is a prodrug that passes through the stomach and small intestine largely intact. Upon reaching the colon, **bacterial azoreductase enzymes** (produced by normal colonic flora) cleave the azo bond, releasing two molecules of **5-ASA (mesalamine)**. * **5-ASA** acts locally on the colonic mucosa. * It inhibits the **cyclooxygenase (COX)** and **lipoxygenase (LOX)** pathways → decreasing the production of pro-inflammatory prostaglandins and leukotrienes. * It also acts as a **free radical scavenger**, reducing oxidative tissue damage in the inflamed colon.
各物種劑量
- For dogs who cannot tolerate sulfasalazine · 10-20 mg/kg · PO · three times daily
- Chronic colitis · 10-20 mg/kg · PO · q8h · Has had limited use in dogs without causing apparent side effects.
- Chronic colitis · 10-15 mg/kg · PO · q8-12h
- Chronic colitis · 5-10 mg/kg · PO · three times daily · Initially, then reduce gradually.
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 olsalazine or salicylates
不良反應
- Keratoconjunctivitis sicca (KCS / dry eye) - less frequent than with sulfasalazine
- Diarrhea (paradoxical worsening reported in humans)
- Vomiting (especially with overdose)
- Decreased motor activity (with overdose)
- Elevated ALT or AST
藥物相互作用
- Warfarin · Olsalazine may increase prothrombin times in patients receiving warfarin.
監測
- Clinical efficacy (resolution of colitis signs)
- Adverse effects (especially signs of KCS/dry eye)
- Schirmer Tear Test (STT) periodically
- Serum ALT and AST
過量
Overdosage in dogs may cause **vomiting, diarrhea, and decreased motor activity**. * **Toxicity:** Dosages up to 2 grams/kg were not lethal in dogs. * **Treatment:** Treat symptomatically and supportively. GI decontamination may be considered if a massive overdose was recently ingested.
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。