硫普羅寧 (Tiopronin)
**硫普羅寧 (Tiopronin)** 是一種專門的**抗尿結石劑**，主要用於獸醫學中以管理和預防犬隻的**胱氨酸尿結石**（膀胱結石）。胱氨酸尿症是一種遺傳性代謝缺陷，導致腎小管對某些氨基酸（特別是胱氨酸）的重吸收出現問題，而胱氨酸在酸性尿液中極難溶解，容易形成結石。 當飲食調整（超低蛋白、鹼化飲食）和尿液鹼化無法完全溶解或預防這些結石復發時，通常會使用硫普羅寧。 * **主要特點：** * 作為**螯合劑**，增加尿液中胱氨酸的溶解度。 * 通常比青黴胺 (penicillamine) 更受青睞，因為其潛在的不良反應發生率較低，儘管價格相對昂貴。 * 需要終身治療和飼主的嚴格配合才能達到預防成功。
作用機制: Tiopronin is an active **sulfhydryl (-SH) compound**. In the urine, it undergoes a **thiol-disulfide exchange** with cystine (which is a cysteine-cysteine disulfide). * **Mechanism Pathway:** Tiopronin + Cystine → **Tiopronin-Cysteine Disulfide Complex** + Cysteine. * This newly formed complex is up to 50 times more water-soluble than cystine alone. * By increasing the solubility of cystine in the urine, tiopronin prevents the precipitation of cystine crystals and facilitates the gradual dissolution of existing **cystine calculi**.
各物種劑量
- Prophylactic treatment of cystine urinary calculi · 30 mg/kg PO q12h · PO · q12h · Increase water intake and urine diuresis. Alkalinize urine (pH 6.5-7.0) using potassium citrate. In cases with low cystine excretion and low urolith recurrence rate, tiopronin dose may be individually decreased (<30 mg/kg) or stopped.
- Dissolution of uroliths · Approximately 40 mg/kg PO q12h · PO · q12h · Reevaluation of uroliths with ultrasound or radiography every 4th week. After urolith dissolution, give prophylactic dose. If urolith dissolution is not achieved after 2-3 months, surgery is recommended.
- In conjunction with an alkalinizing, protein and sodium restricted diet (e.g., u/d) · 30-40 mg/kg PO divided into two daily doses · PO · divided into two daily doses
- Treatment of cystine urinary calculi · 20 mg/kg PO twice daily · PO · twice daily · 1-3 months · Relatively high incidence of adverse effects
- Prevention of cystine urinary calculi · 15 mg/kg PO twice daily · PO · twice daily
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
- Agranulocytosis
- Aplastic anemia
- Thrombocytopenia or other significant hematologic abnormality
- Impaired renal or hepatic function
- Sensitivity to either tiopronin or penicillamine
不良反應
- Coombs'-positive regenerative spherocyte anemia
- Aggressiveness
- Proteinuria
- Thrombocytopenia
- Elevations in liver enzymes and bile acids
- Dermatologic effects (small pustules, dry crusty nose, ecchymosis, itching, rashes, mouth ulcers, jaundice)
- Myopathy (staggering, difficulty chewing)
- Lethargy
- Sulfur odor of the urine
- GI distress
- Allergic reactions (adenopathy)
- Arthralgias
- Dyspnea
- Fever
- Edema
- Nephrotic syndrome
藥物相互作用
- Nephrotoxic drugs · Potentially additive toxic effects
- Hepatotoxic drugs · Potentially additive toxic effects
- Bone marrow depressing drugs · Potentially additive toxic effects
監測
- Physical examination (1, 3, 6, & 12 months after start, then twice a year)
- Ultrasonography/radiography of the urinary tract
- Urinalyses (specific gravity, protein, pH, sediment, and cyanide nitroprusside reaction) using AM samples
- CBC (with platelets)
- Liver enzymes (alkaline phosphatase, ALT)
- Quantitative measurements of urinary cystine excretion related to urinary creatinine excretion (AM samples, before start and once a year during treatment)
過量
There is little information available regarding acute toxicity or overdosage of tiopronin in veterinary species. It is suggested to contact an animal poison control center for further information and guidance in the event of an overdose situation. Treatment would likely be supportive and symptomatic.
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。