dosing, and contraindications. Sadly, that is occurring less and less with burnout, overwork, and the politics of working in many areas of health care now. Some, but not all of my colleagues at least check new drugs against known interactions with constantly updated apps on their phones--but that is assuming one knows all the drugs (and nutritional supplements) a patient might be on. The same challenges exist for pharmacists, despite their computerized data at their fingertips.
Those patients who see many physicians, shop multiple pharmacies for prescription drugs or, again, take a lot of nutritional supplements, are at especially higher risk. As difficult and time-consuming as it might be, many need an informed patient advocate (family member willing to stay on top of things or another person) to intercede on their behalf. Few have that, though. (And no, HIPAA need not be a barrier, if the advocate obtains the proper permissions from the patient).
"Best health care system in the world..." Maybe for a fortunate few. sigh...