In Act v of Macbeth by William Shakespeare, the Doctor thinks that Lady Macbeth is suffering from troubles in her mind, which are keeping her from sleeping soundly.
Macbeth wants the Doctor to cure his wife, and he would like the clinician to give her some medicine that may erase the troubling thoughts from Lady Macbeth's mind.
On the other side, the Doctor replies that Lady Macbeth will have to erase these thoughts herself.
Macbeth is obviously upset by this, and says that the Doctor is throwing medicine to the dogs.