It's the odd North American English "abbreviation" for a "prescription medicine". Where a "prescription medicine" is one that cannot be bought directly by a co

It's the odd North American English "abbreviation" for a "prescription medicine". Where a "prescription medicine" is one that cannot be bought directly by a consumer and instead requires a medical professional to prescribe it: https://en.wikipedia.org/wiki/Medical_prescription https://en.wikipedia.org/wiki/Medical_prescription