烏洛托品 / 孟德立酸烏洛托品
Methenamine
Hexamethylenetetramine
別名: Hiprex · Hexamine hippurate · Methenamine hippurate
由 VetSheet 獸醫團隊審訂更新於 2026年4月5日本內容以實證獸醫文獻為本
各物種劑量
此藥的劑量資料尚未收錄於 VetSheet 藥典，以下其他章節資料完整。處方前請參閱最新藥品說明書。
概覽
烏洛托品（又稱六亞甲基四胺）是一種泌尿道抗菌劑，主要用於預防和長期管理反覆發作的下泌尿道感染。
臨床提示： 它不是傳統的抗生素，而是一種前驅藥。因為它的療效完全依賴於在酸性環境中轉化為甲醛，所以它在鹼性尿液中或對全身性感染無效。細菌對甲醛不會自然產生抗藥性，這使其非常適合用於慢性感染管理。
作用機制
Methenamine is a prodrug that is hydrolyzed in an acidic environment (urine pH < 5.5) → ammonia and formaldehyde.
Formaldehyde acts as a non-specific bactericidal agent that denatures bacterial proteins and nucleic acids. It requires sufficient time in the bladder to convert and exert its effects.
安全性與警告
禁忌症
- Renal insufficiency (can exacerbate systemic acidosis)
- Severe hepatic disease (due to ammonia production)
- Severe dehydration
- Metabolic acidosis
- Concurrent use of sulfonamides
不良反應
- Gastrointestinal upset (nausea, vomiting, diarrhea)
- Dysuria or pollakiuria (due to formaldehyde irritation)
- Hematuria
- Crystalluria (at high doses)
注意事項
Urine pH must be monitored and maintained below 5.5 for the drug to be effective. Not effective for upper urinary tract infections (pyelonephritis) or systemic infections. Use with caution in patients with pre-existing gastrointestinal disease.
藥物相互作用
Formaldehyde forms an insoluble precipitate with sulfonamides, increasing the risk of crystalluria and renal damage.
Raises urine pH, preventing the conversion of methenamine to its active form (formaldehyde).
May increase urine pH and promote diuresis, reducing formaldehyde concentration and contact time in the bladder.
監測
- Urine pH (target < 5.5)
- Urinalysis (monitor for crystalluria or hematuria)
- Renal function
- Hepatic function (in prolonged use)
藥物動力學
半衰期
吸收
Rapidly absorbed from the gastrointestinal tract.
分佈
Widely distributed throughout the body, but only active in the urinary tract where it concentrates and hydrolyzes.
代謝
Approximately 10-30% may be hydrolyzed in the acidic environment of the stomach unless administered as an enteric-coated formulation or with a salt (like hippurate) that delays gastric hydrolysis.
排除
Excreted almost entirely unchanged in the urine, where it subsequently hydrolyzes to formaldehyde.
過量
Overdosage primarily manifests as severe gastrointestinal distress (vomiting, diarrhea) and urinary tract irritation (hematuria, dysuria, crystalluria). Treatment is supportive and symptomatic. Alkalinizing the urine can halt further conversion to formaldehyde and reduce urinary irritation.
可用產品
劑型
- 150 mg methenamine + 116 mg monosodium phosphate tablet
- 1 g methenamine hippurate tablet
人用標示
- Hiprex 1 g tablet
各地核准狀態
Human-approved formulations used off-label in veterinary medicine.
POM (Prescription Only Medicine)
POM (Prescription Only Medicine)
暫無法規資料: 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
儲存與穩定性
Store at room temperature (15-30°C) in a tightly closed container. Protect from moisture and light.
飼主須知
請隨餐餵食此藥物以減少腸胃不適。
您的獸醫可能會建議特定的飲食或泌尿道酸化補充劑；嚴格遵守這些指示至關重要，因為此藥物只有在尿液呈酸性時才有效。
請確保您的寵物隨時有乾淨的飲水。未經獸醫同意，請勿給您的寵物服用任何非處方制酸劑。
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。