The word "prescription" can be decomposed into "pre" and "script" and literally means "to write before" a drug can be prepared. The concept of prescriptions date back to the beginning of history. So long as there were medications and a writing system to capture directions for preparation and usage, there were prescriptions. Latin served a good purpose on prescriptions when they were first written in the 1400s. Spread widely by Roman soldiers and traders, Latin was the main language of western Europe for hundreds of years. It was unlikely to change, because it was a "dead" language, and it was unlikely to be misinterpreted, because it was exact in its meaning. Of course, the patients who didn't know Latin probably didn't have the vaguest idea what they were taking.
Who can issue prescriptions are governed by local legislation. In the United States, all states, physicians, veterinarians, dentists, and pediatrists have full prescription power. Many countries allow mid-level practitioners different prescription privileges. Nurse practitioners, physician assistants, optometrists, homeopathic physicians, registered pharmacists, naturopathic physicians, and doctors of oriental medicine currently represent the spectrum of mid-level practitioners. Each country regulates what (if any) prescription powers members of the above group are allowed.
Prescriptions are typically written on preprinted prescription forms that are assembled into pads. Preprinted on the form is text that identifies the document as a prescription, the name and address of the hospital or the prescribing doctor.
Predating modern legal definitions of a prescription, a prescription traditionally is composed of four parts: a "superscription", "inscription", "subscription" and "signature".
1. The “superscription”section contains the date of the prescription and patient information (name, address, age, etc).
2. The word “Recipe:” (in English prescriptions “Rx”) addressed to the pharmacist separates the superscription from the “inscriptions” section. This is literally an abbreviation for an exhortation to the patient to “take to” what is described in the inscription section. The inscription section defines what is the medication.
3. The “subscription” section contains dispensing directions to the pharmacist. This may be compounding instructions or quantities.
4. The “signature” section contains directions to the patient.
Latin in Prescriptions in Some English-speaking Countries: The only part of a prescription where Latin appears today, however, is in the directions for taking the drug. This use has become a kind of medical shorthand. Some of these abbreviated terms have the potential to cause medication errors because they look so similar in handwriting, so their use is on the decline.