スルファダイアジン

外観

白色～わずかにうすい黄色, 結晶性粉末～粉末

溶解性

希塩酸, 水酸化ナトリウム試液, アンモニア試液に可溶, アセトン, エタノールに難溶, 水に不溶水酸化ナトリウム溶液に溶けやすく、水にほとんど溶けない。

解説

スルファダイアジンは，サルファ剤の一種。ぶどう球菌・大腸菌などに抗菌力を持ち、皮膚の細菌感染症や肺炎・赤痢などに用いる。小学館 デジタル大辞泉について　情報 | 凡例

用途

スルファジアジン（Sulfadiazine）は、サルファ薬の一つ。感染源の細菌細胞内での葉酸の合成を阻害することによって殺す効果があり、尿路感染症（UTIs）の治療に使われる。 スルファジアジンとピリメタミンとの組み合わせは、トキソプラズマ（Toxoplasma gondii）が原因のトキソプラズマ症の治療に使われる。

用途

細菌性下痢症、ヘモフィルス感染症 (豚) 。

効能

抗菌薬, 葉酸合成阻害薬

化学的特性

White to slightly yellow crystalline pow

使用

It is used in the form of silver salts (sulfadiazine silver) as an external antibacterial agent, primarily for treating burns. It is believed that the presence of the silver ion in the molecule facilitates increased antimicrobial and wound-healing action.

定義

ChEBI: A sulfonamide consisting of pyrimidine with a 4-aminobenzenesulfonamido group at the 2-position.

抗菌性

Sulfadiazine is somewhat more active than other sulphonamides.

一般的な説明

Sulfadiazine’s plasma half-life is 17 hours. It is a white,odorless crystalline powder soluble in water to the extentof 1:8,100 at 37°C and 1:13,000 at 25°C, in human serumto the extent of 1:620 at 37°C, and sparingly soluble in alcoholand acetone. It is readily soluble in dilute mineralacids and bases. Its pKa is 6.3.

応用例（製薬）

Sulfadiazine is almost insoluble in water and unstable on exposure to light. It is administered orally or, as the sodium salt, by intravenous injection. It is a component of several multi-ingredient preparations. Its low solubility in urine led to its general replacement by other compounds. The intravenous solution is highly alkaline and should not be given by any other route.

薬物動態学

Oral absorption： Very good
C_max 3 g oral： c. 50 mg/L after 3–4 h
Plasma half-life ：7–12 h
Volume of distribution： 0.36 L/kg
Plasma protein binding： c. 40%
Absorption and distribution
Adequate blood concentrations are easily achieved and maintained after oral administration. It is well distributed and penetrates in therapeutic concentrations into the CSF, but because of resistance it is no longer the drug of choice in meningitis. It crosses the placenta and enters breast milk to achieve concentrations around 20% of plasma levels.
Metabolism and excretion
Sulfadiazine is subject to acetylation in the liver. The acetyl derivative lacks antibacterial activity and is excreted more slowly (half-life 8–18 h). Parent compound and metabolite are both excreted mainly by glomerular filtration.

臨床応用

Urinary tract infection
Nocardiasis
Chancroid
Toxoplasmosis (in combination with pyrimethamine)
Meningococcal infections
Prophylaxis of rheumatic fever

副作用

In addition to side effects common to the group, sulfadiazine inhibits the metabolism of phenytoin. The risk of crystalluria can be reduced by high fluid intake and alkalization of the urine.

安全性プロファイル

Poison by intravenous route. Moderately toxic by ingestion and intraperitoneal routes. Human systemic effects by ingestion: hematuria, anuria, general anesthesia, gastrointestinal effects. Experimental teratogenic and reproductive effects. When heated to decomposition it emits very toxic fumes of NOx and SOx.