I beg to differ on the two examples I gave.
Research study monitors do not need to have had direct patient care. Not all of them are nurses; one lady I know has a BA in Music; another gentleman has a BA in psychology; a third was previously a lab tech who worked with AIDS viruses. None of these three have ever done anything in the way of patient care. The companies however tend to like nurses as opposed to other degrees because they have the medical terminology
across a wide range of areas, they can spot AEs, they know their drugs so they know if a drug was being taken for an event that was not the event being studied. I think about half of the monitors I've worked with are nurses.
Pharmaceutical salespeople (and other medical salespeople, such as EKG equipment) are also not all nurses although they do all have some degree, preferably a four-year science oriented degree...but even that is not set in stone. The important thing is being able to SELL. But again, nurses do seem to be on the preferred list of job candidates.
Job postings always target the "perfect" candidate. That doesn't mean someone who doesn't fit perfectly won't be hired (or won't do a good job).