デキサメタゾン

解説C22H29FO5(392.46)．1958年，G.E. Arthらにより16α-メチルヒドロコルチゾン=アセタートから合成された．ベタメタゾンの16位のメチルがα配位であることが異なるのみである．白色～微黄色の結晶．分解点約245 ℃．[α]20D＋72～＋80°(ジオキサン)．メタノール，エタノール，アセトンまたはジオキサンに微溶，水，エーテルに難溶．デキサメタゾンは，副じん皮質ホルモン作用，とくにグルココルチコイド作用が強い．ヒドロコルチゾンの25倍の抗炎症作用をもつ．リウマチ性関節炎，アレルギー性疾患，皮膚疾患，アレルギー性および炎症性眼疾患などの治療に用いられる．LD50 120 mg/kg(ラット，皮下)．森北出版「化学辞典（第2版）

用途無血清培地添加剤、薬理研究用。

用途副腎皮質ホルモン剤です。糖 質コルチコイドの 16β 位にメチル基が付加し ています。鉱質コルチコイド作用を弱めた性 質を有しています。

説明The activity of dexamethasone, as measured by glycogen deposition, is 20 times greater than that of hydrocortisone. It has five times the anti-inflammatory activity of prednisolone. Clinical data indicate that this compound has seven times the antirheumatic potency of prednisolone. It is roughly 30 times more potent than hydrocortisone. Its pharmacokinetics are presented in Table 33.3. Routes of metabolism for dexamethasone are similar to those for prednisolone, with its primary 6β-hydroxy metabolite being recovered in urine. Dexamethasone sodium phosphate is the water-soluble sodium salt of the 21-phosphate ester, with an IV half-life of less than 10 minutes because of rapid hydrolysis by plasma phosphatases. Peak plasma levels for dexamethasone usually are attained in approximately 10 to 20 minutes following its IV administered dose. A similar reaction occurs when the phosphate ester is applied topically or by inhalation.

来歴A group of chemists at Merck discovered dexamethasone, a steroid hormone, in 1958 as an anti-inflammatory steroid. Merck marketed dexamethasone with a brand name Decadron in 1959.Since its emergence on the market in 1959, dexamethasone has become one of the two most popular orally bioavailable corticosteroids. The other one is prednisone. Having been on the market for over sixty years, dexamethasone has been tried with certain degree of success for many indications, making it seem like a panacea. For instance, it has been found to have efficacy for rheumatic problems, a number of skin diseases, severe allergies, asthma, chronic obstructive lung disease, croup, brain swelling, and along with antibiotics in tuberculosis. Doctors are very familiar with dexamethasone’s pharmacological properties. Therefore, they have been using this drug on severe COVID patients "off label" to relieve their pneumonia symptoms.

使用Dexamethasone is used for the same indications as all corticosteroids; however, it exhibits a significantly more powerful anti-inflammatory and anti-allergic action. It is used for circulatory collapse—shock during or after surgical operations, trauma, blood loss, myocardial infarction, and burns. It is also used in severe infections—toxemia, vascular collapse in meningococcosis, septicemia, diphtheria, typhoid fever, and peritonitis. It is used in severe allergic conditions—asthmatic status, laryngeal edema, severe anaphylactic reactions to medicinal drugs, and pyrogenic reactions.