Prescriptions are typically handwritten on
preprinted prescription forms that are assembled into pads, or
alternatively printed onto similar forms using a computer
printer. Preprinted on the form is text that identifies the
document as a prescription, the name and address of the
prescribing doctor and any other legal requirement such as a
registration number (e.g. DEA Number in the United States).
Unique for each prescription is the name of the patient, date
(some jurisdictions may place a time limit on the
prescription[1] (http://www.med.rug.nl/pharma/who-cc/ggp/chapter9/page01.htm)),
the "recipe" of the medication and the directions for taking it.
Finally there is the doctor's signature.
The symbol "Rx" meaning "prescription" is a transliteration of a
symbol resembling a capital R with a cross on the diagonal ( ℞).
There are various theories as to the origin of this symbol -
some note its similarity to the eye of Horus, others to the
ancient symbol for Jupiter, both gods whose protection may have
been sought in medical contexts. Alternatively, it may be
intended as an abbreviation of the Latin recipere, "to take" [2]
(http://www.m-w.com/cgi-bin/dictionary?book=Dictionary&va=recipe),
and it is quite possible that more than one of these factors
influenced its form. Literally, "Rx" indicates an instruction
"to take" what is specified in the prescription, although this
was probably originally directed at the pharmacist who needed to
take a certain amount of each drug and prepare them, rather than
at the patient who must take the medicine, in the sense of
consuming it.
The word "prescription" can be decomposed into "pre" and
"script" and literally means, "to write before" a drug can be
prepared. Those within the industry will often call
prescriptions simply "scripts".
