Medical prescription

A medical prescription (℞) is a written order by a medical doctor to a pharmacist for a treatment to be provided to the doctor's patient.

History

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 http://www.pharmacy.wsu.edu/History/history02.htmlhttp://139.80.66.65/edmedia/HxPharmacy/Pharmacy_main.asp?doMove=NEXT&thisFile=main_002.txt.

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Modern prescriptions are actually "extemporaneous prescriptions" from the Latin (ex tempore) for "instant"http://www.m-w.com/cgi-bin/dictionary?book=Dictionary&va=extemporaneous. "Extemporaneous" means the prescription is written on the spot for a specific patient with a specific ailment. This is distinguished from the a non-extemporaneous prescription which is a generic recipe for a general ailment. Modern prescriptions evolved with the separation of the role of the pharmacists from that of the physicianhttp://www.bartleby.com/65/ph/pharmacy.html. Today the term "extemporaneous prescriptions" is reserved for "compound prescriptions" which requires the pharmacist to mix or "compound" the medication in the pharmacy for the specific needs of the patient.

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Predating modern legal definitions of a prescription, a prescription traditionally is composed of four parts: a "superscription", "inscription", "subscription" and "signature"http://www.ibiblio.org/herbmed/eclectic/potter-comp/prescription.html.

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The superscription section contains the date of the prescription and patient information (name, address, age, etc). The symbol "Rx" separates the superscription from the inscriptions sections. In this arrangement of the prescription, the "Rx" is a symbol for recipe or literally "take thou". This is most likely an exhortation to the pharmacist by the doctor, "I want the patient to have the following medication"http://www.vnh.org/HospitalCorpsman14295/14295_ch6.pdf. It should not be interpreted as instructions to the patient to "take thou" as patient instructions are in a later section. Some the literal exhortation to the pharmacist is "take thou this recipe".

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The inscription section defines what is the medication. The inscription section is further composed of one or more ofhttp://2.1911encyclopedia.org/T/TH/THERAPEUTICS.htm:

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• a "basis" or chief ingredient indended to cure (curare)
• an "adjuvant" to assist its action and make it cure quickly (cito)
• a "corrective" to prevent or lessen any undesirable effect (tuto)
• a "vehicle" or "excipient" to make it suitable for administration and pleasant to the patient (jucunde)

The "subscription" section contains dispensing directions to the pharmacist. This may be compounding instructions or quantities.

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The "signature" section contains directions to the patienthttp://www.m-w.com/cgi-bin/dictionary?book=Dictionary&va=signature and is often abbreviated "Sig."http://www.bartleby.com/61/96/S0399600.html or "Signa." It also obviously contains the signature of the prescribing doctor though the word "signature" has two distinct meanings here and the abbreviations are sometimes used to avoid confusion.

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Thus sample prescriptions in modern textbooks are often presented as:

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Rx: medication

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Disp.: dispensing instructions

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Sig.: patient instructions

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