noun
quick-acting remedy; fast-acting medicine
Refers to a medicine or treatment that works quickly. Can also be used figuratively for a swift solution.
この即効薬を飲めば、すぐに痛みが治まる。
If you take this fast-acting medicine, the pain will subside right away.
彼のアドバイスは、まるで即効薬の
His advice solved the problem like a quick-acting remedy.