In Shakespeare's play, Macbeth, in Act Five, there is reference to illness and medication.

In Act Five, scene one, Lady Macbeth, ironically is troubled over the deaths she and/or Macbeth are responsible for, and she starts walking and talking in her sleep. Her famous lines refers to the murder of Duncan and all the blood, her husband's fear to commit the deed and visions of death:

Out, damned spot! Out, I say! One–two—
why then ’tis time to do't. Hell is murky. Fie, my lord, fie!
A soldier, and afeard? What need we fear who knows it,
when none can call our power to account? Yet who would
have thought the old man to have had so much blood in him? (31-35)

The Doctor and a Gentlewoman watch her in such a state; in is obvious that the two are hearing things they should not be listening to; and it is no secret by this time that those people closest to the Macbeths end up dead (Duncan, Banquo, the Macduffs, etc.).

Foul whisperings are abroad. Unnatural deeds
Do breed unnatural troubles: infected minds
To their deaf pillows will discharge their secrets:
More needs she the divine than the physician.
God, God, forgive us all! Look after her;
Remove from her the means of all annoyance,
And still keep eyes upon her. So good night:
My mind she has mated, and amazed my sight:
I think, but dare not speak. (63-71)

The Doctor admits that unnatural deeds (murder) can affect someone's mind. Often they will speak to their pillows or talk in their sleep, when no one can hear them ("deaf pillow"). He suggests that the Gentlewoman remove anything with which Lady Macbeth might harm herself, and that she should watch her still. He admits that he is amazed by what he has seen and heard: but regardless of his thoughts, he knows better than to speak of them.

By Act Five, scene three, when chaos is descending on Macbeth with rumors of war, his men are joining the other side, and he is worrying of Malcolm approaching, Macbeth asks the Doctor about his wife:

How does your patient, doctor? (42)

The Doctor responds by saying that her thoughts, imaginings, trouble her and keep her from her sleep. So Macbeth speaks to the Doctor regarding illness and healing:

Cure her of that.
Canst thou not minister to a mind diseased,
Pluck from the memory a rooted sorrow,
Raze out the written troubles of the brain,
And with some sweet oblivious antidote
Cleanse the stuff'd bosom of that perilous stuff
Which weighs upon the heart? (46-52)

Macbeth asks the Doctor if he cannot heal her of her "diseased mind," remove, somehow, the thoughts that are rooted so deeply in her psyche. Mention of medicine is found with Macbeth's reference to "some sweet oblivious antidote" (50) that could lighten her heart somehow: does the Doctor have such a thing?

The Doctor answers that she must find a way to heal herself:

Therein the patient / Must minister to himself. (52-53)