Alphaoverlord is 100% correct. While standards and norms may vary from place to place, the textbooks that I have read on medical ethics are in agreement. In my pre-medical, medical, and postgraduate-medical training, I have always been taught that my mandate is to do the right thing for the person sitting in front of me. This in itself can lead to population-level problems, but that is a separate issue (social justice, the 4th of the principles that alphaoverlord outlined).

Also, a nitpick: it's nonmaleficence (doing no harm), not malfeasance.