イベルメクチン

解説イベルメクチンは米国の製薬会社メルク・アンド・カンパニーが製造している寄生虫駆除薬。商品名は「メクチザン」。動物の寄生虫の駆除のほか、「河川盲目症（オンコセルカ症）」など寄生虫によって引き起こされる人間の感染症にも効果が認められている。同社と日本の有機化学者・大村智が、同氏の発見した化合物「エバーメクチン」を改良して開発し、1981年、家畜やペットの寄生虫駆除薬として製品化した。その後の臨床研究で人間の感染症にも有効なことが判明し、87年よりメルク社が世界保健機関（WHO）を通じて蔓延地に無償提供を行っている。出典 朝日新聞出版/知恵蔵miniについて

用途イベルメクチンは、マクロライド類に属する物質。腸管糞線虫症の経口駆虫薬、疥癬、毛包虫症の治療薬でもある。商品名はストロメクトール(日本ではMSD社製造、マルホ社販売)。放線菌が生成するアベルメクチンの化学誘導体。

説明Ivermectin is an antiparasitic agent effective in the treatment of onchocerciasis, or "river blindness". Since ivermectin acts to prevent the adult worm from producing microfilariae, it needs to be administered only once or twice a year.

来歴The discovery of ivermectin was the result of a landmark collaboration in the 1970s between Merck & Co. and the Kitasato Institute in Japan. Microbiologist Satoshi Ōmura isolated a new Streptomyces species—Streptomyces avermitilis—from Japanese soil and sent its cultures to Merck. Merck scientist William C. Campbell then discovered ivermectins, a natural product with potent anthelmintic activity. To reduce its toxicity to mammals and optimize its efficacy, Merck chemists performed semi-synthetic modifications on ivermectin, hydrogenating it to obtain the derivative ivermectin. This optimization significantly improved the drug's safety, leading to its market launch as a highly effective veterinary drug in 1981. Its historic contribution lies in its application in human medicine: after demonstrating its remarkable efficacy against river blindness, Merck decided in 1987 to donate ivermectin (Mectizan®) indefinitely for the control and elimination of river blindness and lymphatic filariasis worldwide. This achievement ultimately earned Satoshi Ōmura and Campbell the 2015 Nobel Prize in Physiology or Medicine.

製造方法The synthesis of ivermectin involves the hydrogenation of the naturally occurring avermectin B1 (abamectin) at the double bond linking C-22 and C-23. This results in a mixture of two homologues, 22, 23-dihydroavermectin B1a (H2B1a) and 22, 23-dihydroavermectin B1b (H2 B1b). The a- and b- nomenclature refers to the presence on C-25, of either a secondary butyl side chain or an isopropyl group, respectively. The biological activities of H2B1a and H2B1b are similar. Large-scale separation of the two homologues is not practical, and, hence, ivermectin is marketed as a mixture of H2 B1a (>80%) and H2 B1b (