薬くすりが効ききすぎる

expression, ichidan verb

to work too well (of a punishment, reprimand, etc.); to be too much (for someone); to have a stronger effect than intended

Idiomatic expression used when a punishment, scolding, or harsh measure has an excessive effect, often implying it backfires or causes unintended suffering. The 'medicine' metaphor suggests the remedy is too strong.

• 彼かれを叱しかったら、薬くすりが効ききすぎて落おち込こんでしまった。

  When I scolded him, it worked too well and he got depressed.

• 軽かるい注ちゅう意いのつもりだったが、薬くすりが効ききすぎて彼かの女じょは泣なき出だした。

  I meant it as a light warning, but it had a stronger effect than intended and she burst into tears.