Doctor: Therein the patient
Must minister to himself.
MACBETH: Throw physic to the dogs; I'll none of it.
Come, put mine armour on; give me my staff.
Seyton, send out. Doctor, the thanes fly from me.
Come, sir, dispatch. If thou couldst, doctor, cast 
The water of my land, find her disease,
And purge it to a sound and pristine health,
I would applaud thee to the very echo,
That should applaud again.--Pull't off, I say.--
What rhubarb, senna, or what purgative drug, 
Would scour these English hence? Hear'st thou of them?
Doctor: Ay, my good lord; your royal preparation
Makes us hear something.
MACBETH: Bring it after me.
I will not be afraid of death and bane,
Till Birnam forest come to Dunsinane. 
Doctor: [Aside] Were I from Dunsinane away and clear,
Profit again should hardly draw me here.