A medical prescription (Rx) is a written order by a medical doctor to a pharmacist for a treatment to be provided to the doctor's patient.
Format and Definition
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 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]), the "recipe" of the medication and the directions for taking it. Finally there is the doctor's signature.
The symbol "Rx" means "prescription" and is derived from the abbreviation "rx" [1] from the Latin word "to take", recipere[1]. Literally, "Rx" is an instruction to the patient, "to take" what is specified in the prescription. 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".
Many brand name drugs have less expense generic drug substitutes that are chemically equivalent. Prescriptions will also contain instructions on whether the doctor will allow the pharmacist to substitute a generic version of the drug. This instruction is communicated in a number of ways. In some jurisdictions, the preprinted prescription contains two signature lines: one line has "dispense as written" printed underneath; the other line has "subsitution permitted" underneath. Some have a preprinted box "dispense as written" for the doctor to check off (but this is easily checked off by anyone with access to the prescription). Other jurisdictions the protocol is for the doctor to handwrite one of the following phrases: "dispense as written", "DAW", "brand necessary", "do not substitute", "no substitution", "medically necessary", "do not interchange"[1].
As a guideline, pediatric prescriptions should include the age of the child if the patient is less than twelve and the age and months if less than five. (In general, including the age on the prescription is helpful.) In some jurisdictions, it may be a legal requirement to include the age of child on the prescription [1]. Adding the weight of the child is also helpful.
Prescriptions often have a "label" box [1]. When checked, pharmacist is instructed to label the medication. When not checked, the patient only receives instructions for taking the medication and no information about the prescription itself.
Some doctors further inform the patient and pharmacist by providing the indicator for the medication; i.e. what is being treated. This assists the pharmacist in checking for errors as many common medications can be used for multiple medical conditions.
Some prescriptions will specify whether and how many "repeats" or "refills" are allowed; that is whether the patient may obtain more of the same medication without getting a new prescription from the doctor. Legislation may restrict some categories of drugs from being refilled.
In group practices, the preprinted portion of the prescription may contain multiple doctors' names. Doctors typically circle themselves to indicate who is prescribing or there may be a checkbox next to their name.
When filled by the pharmacist, prescriptions are typically assigned a "prescription number" (often abbreviated "Rx#") that is unique to the pharmacy that filled the prescription. The prescription number is written right on the prescription by the pharmacist. The prescription number has the practical purpose of uniquely identifying the prescription later on while filed (both manual and electronic). The prescription number is also put on the label on the dispensed medication. The patient may be required to reference the prescription number for refills and drug insurance claims. There may also be a legal requirement for prescription numbers for subsequent identification purposes.
As a legal document, some jurisdictions will mandate the archiving of the original paper prescription in the pharmacy. Very rarely can the patient take the original prescription with them. The retention period varies but can be as long as six years. See Exhibit B for sample legislation governing the archiving of prescriptions. Once the retention period has passed, privacy legislation may dictate what can be done with the original paper prescription. Legislation may also dictate what happens to the prescriptions if the pharmacy closes or is sold.
Prescriptions for non-narcotic drugs may also be "transferred" from one pharmacy to another for subsequent repeats to be dispensed from another pharmacy. The physical piece of paper that is the prescription is not transferred, but all the information on it is transferred from one pharmacy to another. Legislation may dictate the protocol by which the transfer occurs and whether the transfer needs to be noted on the original paper prescription.
It is estimated that 3 billion (3 thousand million) prescriptions were written in the United States in 2002class="external">[1
Some doctors will use prescription pads that contain similar security measures as checks to make photocopying prescriptions harder. These security measures may be mandated by law - see Exhibit C for sample legal specifications. Prescribers can make it harder for amount forgeries by writing out the amounts in words. Again, this may be mandated by law[1].
Some jurisdictions help control stolen prescriptions by requiring special "triplicate prescriptions" for certain classes of drugs[1]. Blank triplicates are only available from the regulating agency and are individually numbered. The doctor retains a copy, the second and third copies are given to the patient to give to the pharmacist. The pharmacist retains the second copy and the third copy is submitted to the regulating agency. The regulating agency can issue lists of stolen prescriptions that pharmacists can check. In this example, the prescription's validity is further limited to 72 hours from issuance. This system also has the further benefit of managing "double doctoring" where patients visit multiple doctors to get prescriptions.
When forgery is suspected, pharmacists will call the doctor to verify the prescription and will attempt to detain the suspect pending arrival of authorities. Forged prescriptions are no longer considered medical documents and doctor-patient confidentiality rules no longer applies.
To avoid ambiguity, the following abbreviations are not recommended [1]:
Doctors will often use blank prescriptions as general letterhead. A "doctor's note" for absent days from school or work for minor illnesses will often be written on a blank prescription.
Legislation may define certain equipment as "prescription devices"[1]. Such prescription devices can only be used under the supervision of authorized personnel and such authorization is typically documented using a prescription. Examples of prescription devices include dental cement (for affixing braces to tooth surfaces), various prothesis, gut sutures, sickle cell tests, cervical cap and ultrasound monitor.
In some jurisdictions, hypodermic syringes are in a special class of its own, regulated as illicit drug use accessories[1] separate from regular medical legislation. Such legislation will often specify a prescription as the mean by which one may legally possess syringes.
Contents of the prescription
Both pharmacists and physicians are regulated professions in most jurisdictions. A prescription as a communications mechanism between them is also regulated and is a legal document. Legislation may define what constitutes a prescription, the contents and format of the prescription (including the size of the piece of paper - see Exhibit C paragraph 10) and how prescriptions are handled and stored by the pharmacist. Many jurisdictions will now allow faxed or phone prescriptions containing the same information. Exhibit A below illustrates the legal definition of a prescription.Handling of the prescription
When filled by a pharmacist, as a matter of business practice, the pharmacist may write certain information right on the prescription. This may also be mandated by legislation (see Exhibit D). Information such as the actual manufacturer of the drug and the date the medication was dispensed may be written right onto the prescription. Legislation may require the pharmacist sign the prescription. In computerized pharmacies, all such information is printed and stapled to the prescription. Sometimes such information is printed onto labels and the labels affixed right onto the prescription.Forgeries
Prescriptions are sometimes forged because many narcotics are cheaper and safer as prescription drugs than as street drugs. Forgery takes many forms: Doctor's prescription pads are sometimes stolen by drug addicts, amounts may be altered on legitimate prescriptions, call back numbers may be falsified and phoned or faxed prescriptions faked[1]. Writing Prescriptions
Who can write prescriptions
Who can issue prescriptions are governed by local legislation. Some examples are: veterinarians, dentists, some nurse practictioners. Ophthalmologists will also issue prescriptions for corrective eyeglasses, though technically these are not medical prescriptions.Legibility of prescriptions
Prescriptions, when handwritten, are notorious for being often illegible (5% according to an Irish study [1]). Contrary to popular belief, pharmacists do not have special deciphering skills. When in doubt, they call the doctor. At other times, even though some of the individual letters are illegible, the position of the legible letters and length of the word is sufficient to distinguish the medication based on the knowledge of the pharmacist. For doctors that the pharmacist deals with regularly, they learn to read the doctor's handwriting. Patients are advised to ensure that the prescription is legible before leaving the doctor's office. Some jurisdictions have made legible prescriptions a law (e.g. Florida[1]). Some have advocated the elimination of handwritten prescriptions altogether[1].Writing good prescriptions
Independent of the actual prescribing decision, elements of a good prescription writing include:
[1]
[1]
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Abbreviations
See Appendix 1 for a complete list of common abbreviations found on prescriptions. Many abbreviations are derived from Latin phrases. Hospital pharmacies have more abbreviations, some specific to the hospital. Different jurisdictions follow different conventions on what is abbreviated or not. Prescriptions that don't follow area conventions may be flagged as possible forgeries.Non prescription drug prescriptions
Prescriptions are also used for things that are not strictly regulated as a prescription drug. Doctors will often give non-prescription drugs out as prescriptions because drug benefit plans may reimburse the patient only if the over-the-counter medication is taken under the direction of a doctor. Conversely, if a medication is available over-the-counter, doctors may ask patients if they want it as a prescription and possibly incur a pharmacist's dispensing fee or whether they want to get it themselves at a lower price. If the patient wants the medication not under prescription, the doctor is usually careful to give the mediation name to the patient on a blank piece of paper to avoid any confusion with a prescription. This is applied to non-medications as well. For example, crutches, and registered massage therapy may be reimbursed under some health plans, but only if given out by a doctor as a prescription.Related Usage of the Term "Prescription"
Prescription may also be used as a short form for prescription drugs to distinguish from over-the-counter drugs. It may also be used in reference to the entire system of controlling drug distribution (as opposed to illicit drugs).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 class="external">[1
Modern prescriptions are actually "extemporaneous prescriptions" from the Latin (ex tempore) for "instant"[1]. "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 physician[1]. 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.
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). The symbol "Rx" separates the superscription from the inscriptions sections. In this arrangement of the prescription, the "Rx" is literally an abberviation for an exhortation to the patient to "take thou" what is described in the inscription section.
The inscription section defines what is the medication. The inscription section is further composed of one or more of[1]:
- 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 "signature" section contains directions to the patient[1] and is often abbreviated "Sig."[1]. It also obviously contains the signature of the prescribing doctor though the word "signature" has two distinct meanings here.
Thus sample prescriptions in modern textbooks are often presented as:
Rx: medication Disp.: dispensing instructions Sig.: patient instructions
Future directions of prescriptions
As a prescription is nothing more than information among a doctor, pharmacist and patient, information technology can be applied to it. Existing information technology is adequate to print out prescriptions. Medical information systems in some hospitals do away with prescriptions within the hospital. There are proposals to securely transmit the prescription from the doctor to the pharmacist using smart cards and the internet[1].Within computerized pharmacies, the information on the piece of paper that is the prescription is captured immediately. Thereafter, the prescription is simply an entry within the pharmacy's information system and the paper prescription is stored for legal reasons only.
Pharmacy information systems are a potential source of valuable information for pharmaceutical companies as it contains information about doctor's prescribing habits. Prescription data mining of such data is a developing, specialized field[1].
Appendix 1: Complete List of Abbreviations
This appendix is meant to be a complete list of all abbreviations used in prescriptions. Its listing here does not mean such abbreviations should be used. See main article for discussion on the use of abbreviations. This listing does not include abbreviations for actual pharmaceuticals (which is a separate article in itself.) Capitalization and the use of a period is a matter of style. In the attached list, Latin is not capitalized whereas English acronyms are. The period is used wherever there are letters omitted in the abbreviation.Exhibit A: Sample Legal Definition of a Prescription
Taken from California's Business and Professions Code Section 4040
[1]:
Exhibit B: Sample Legal Requirement for Filing of Prescriptions
From the Mississippi Board of Pharmacy [1]:
Exhibit C: Sample Legal Requirements for Security and Format
From Indiana Board of Pharmacy [1]:
Exhibit D: Sample Requirements on Information Added by the Pharmacist
Taken from the Ontario's Drug and Pharmacies Regulation Act
[1], paragraph 156.