頓とん服ぷく薬やく

noun

single-dose medicine; medicine taken as needed

Refers to medication prescribed to be taken only when symptoms appear, not on a regular schedule. Common in medical contexts.

• 頭ず痛つうがひどいときは、頓とん服ぷく薬やくを飲のんでください。

  When your headache is severe, please take the single-dose medicine.

• この頓とん服ぷく薬やくは、発はつ熱ねつ時じに一いっ回かいだけ服ふく用ようします。

  This single-dose medicine is taken only once when you have a fever.