頓とん服ぷく薬やくとんぷくやくMeanings1nounsingle-dose medicine; medicine taken as neededRefers 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.