he best defense against medication screwups is an informed patient that knows why he is prescribed a particular medication, what if any side effects it may cause, how much how often he is to get it, and then checks the nurse as she lays out that smorgesbrod of pills.
Sadly, this does not work for most folks who are sick enough to be in a hospital in the first place, and definately does not work for the young. It also does not work for parents who both cannot spend 24/7 at their child's bedside and who are mostly caught up in the doctor-as-godhead syndrome.
What I have had the pleasure of experiencing at the local VA is finding out that my wristband "talks to" both the pharmacy and the meds cart in verifying the order the doctor entered. Now my main concern is seeing the doc enters the order properly. (Example: my diuretics are Rx'd tid and can be given up to half-way to the next scheduled dose -- except that no diuretic can be administered between 8 PM and 4 AM or within 4 hours of administering any sedative. My doc and I work this out every time I am admitted mostly because he hates being called by the head nurse for instructions on how to deal with a patient who is refusing meds.) (Yes, when I am going to be knocked out or immobilized I get the dreaded Foley catheter.)
Sadly, I would bet that less than 10% of the patients know about this, and that the doctors/nurses do not try to explain it to patients.
stay safe.