If your doctor directs you to 'abstain from alcohol' would you be OK to have it injected into your veins rather than drink it?
Yes. It would.
A doctor tells a patient to abstain from alcohol if the patient's use of alcohol is bad for his health. But if the same patient shows up at an emergency room with ethyl glycol poisoning he'll likely have alcohol administered to counteract the deadly effect. In each case (i.e., abstention and administration) the reason is the same: best interest of the patient.