スルファメトキサゾール

外観

白色の結晶性粉末～粉末

溶解性

N,N-ジメチルホルムアミド、水酸化ナトリウム溶液に溶け、エタノール(95)にやや溶けにくく、水に極めて溶けにくい。

解説

4-amino-N-(5-methylisoxazol-3-yl)benzenesulfonamide．C10H11N3O3S(253.28)．スルファメトキサゾールは，日本で開発された持続性サルファ剤で，3-アミノ-5-メチルイソオキサゾールとp-アセトアミノベンゼンスルホニルクロリドとを縮合したのち，脱アセチル化すると得られる．白色の結晶．融点169～172 ℃．水に不溶，エタノールに難溶．光によって徐々に着色する．持続性の抗菌剤．カリニ肺炎治療薬，大腸菌による膀胱炎治療薬として使用される．LD50 3900 mg/kg(マウス，経口)．森北出版「化学辞典（第2版）

用途

パラアミノ安息香酸と競合し てジヒドロ葉酸の合成を阻害します。

用途

パラアミノ安息香酸と競合し てジヒドロ葉酸の合成を阻害作用を示しま す。

用途

動物用医薬品定量用の標準品。

用途

スルファメトキサゾール（Sulfamethoxazole、略号：SMX または SMZ）とは、スルホンアミド系の静菌的抗生物質のひとつ。これはしばしばトリメトプリムとの組み合わせで相乗効果（シナジー）を示す。 MRSAを含むブドウ球菌?大腸菌?インフルエンザ菌?嫌気性菌に感受性を持つことが多い。また尿路感染症でしばしば処方される。副鼻腔炎においてペニシリン系薬剤の代替薬として用いられることもある。トキソプラズマ症?ニューモシスチス感染症でも用いられる。

効能

抗菌薬, 葉酸合成阻害薬

説明

Like sulfisoxazole, this drug is effective in treating infections caused by streptococci, gonococci, pneumococci, staphylococci as well as colon bacillus. Unlike sulfisoxazole, only about 70% of it binds with proteins in the plasma after oral administration, and it diffuses mostly to tissues and tissue fluids. However, since it is removed much slower than sulfisoxazole, it does not require frequent administration and is also the drug of choice for many systemic infections. Moreover, it is an ingredient of a combined drug named bactrim, biseptol, and so on (which will be examined later on), which has a fixed correlation with trimethoprim. Synonyms of this drug are gantanol, sinomin, sulfisomezole, and others.

化学的特性

solid

定義

ChEBI: An isoxazole (1,2-oxazole) compound having a methyl substituent at the 5-position and a 4-aminobenzenesulfonamido group at the 3-position.

抗菌性

The intrinsic activity is similar to that of sulfadiazine.

一般的な説明

Sulfamethoxazole’s plasma half-life is 11 hours. Sulfamethoxazole is a sulfonamide drug closely relatedto sulfisoxazole in chemical structure and antimicrobial activity.It occurs as a tasteless, odorless, almost white crystallinepowder. The solubility of sulfamethoxazole in the pHrange of 5.5 to 7.4 is slightly lower than that of sulfisoxazole but higher than that of sulfadiazine, sulfamerazine, or sulfamethazine.Following oral administration, sulfamethoxazole is notabsorbed as completely or as rapidly as sulfisoxazole, andits peak blood level is only about 50% as high.

空気と水の反応

Insoluble in water.

火災危険

Flash point data for Sulfamethoxazole are not available but Sulfamethoxazole is probably non-flammable.

応用例（製薬）

This is the sulfonamide component of co-trimoxazole. It is slightly soluble in water.

薬物動態学

Oral absorption： 85%
C_max 800 mg oral： c.50 mg/L after 3–6 h
Plasma half-life： 6–20 h
Volume of distribution： 12–18 L
Plasma protein binding： 65%
Penetration of extravascular sites, including the CSF, is good. It crosses the placenta and achieves levels in breast milk of about 10% of the simultaneous plasma concentration. It is extensively metabolized, but about 30% of the dose is excreted unchanged in urine so that high concentrations are achieved.

臨床応用

Sulfamethoxazole is used only in combination with the diaminopyrimidine trimethoprim.

副作用

Unwanted effects are those common to sulfonamides. In addition, benign intracranial hypertension has been reported in children. Most side effects of co-trimoxazole are thought to be attributable to the sulfonamide component.

安全性プロファイル

Moderately toxic by ingestion and intraperitoneal routes. Questionable carcinogen with experimental tumorigenic data. When heated to decomposition it emits very toxic fumes of NOx and SOx.