Medical prescription

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A prescription (℞) is a health-care program implemented by a physician or other medical practitioner in the form of instructions that govern the plan of care for an individual patient.^[1] Prescriptions may include orders to be performed by a patient, caretaker, nurse, pharmacist, physician or other therapist. Previously, the term prescription was used in the narrow sense of a physician's instructions to a pharmacist to prepare medications (see compounding pharmacy) and to a patient to take certain medications. However, as medications have increasingly become pre–packaged manufactured products and medical practice has become more complex, the scope of meaning of the term "prescription" has broadened to also include clinical assessments, laboratory tests, and imaging studies relevant to optimizing the safety or efficacy of medication use. Thus, prescribers often write prescriptions for monitoring tests as part of a patient's plan–of-care for taking a medication (e.g., use of the prothrombin time or International Normalized Ratio laboratory assays to monitor warfarin therapy). Further, it has become common for physicians to write prescriptions for non–medication health care programs such as nutritional prescription, eyeglass prescription, exercise prescription, and physical therapy prescription. Prescriptions are often handwritten, though they may be entered electronically via a computerized physician order entry (also called a computerized prescriber order entry system). (See electronic prescribing). Alternatively, they may be issued verbally to the patient, a nurse, a pharmacist or other therapist. Prescriptions have legal implications, as they may indicate that the prescriber takes responsibility for the clinical care of the patient and in particular for monitoring efficacy and safety.

[edit] Format and definition

Prescription symbol

Prescriptions are either entered into a Computer physician order entry system, 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 provider 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. In the United Kingdom the patient's name and address must also be recorded. Each prescription is dated and some jurisdictions may place a time limit on the prescription.^[2] There is the specific "recipe" of the medication and the directions for taking it. Finally there is the medical practitioner's signature.

The symbol "R_x" meaning "prescription" is a transliteration of a symbol resembling a capital R with a cross on the diagonal (℞).

There are various theories about the origin of this symbol - some note its similarity to the Eye of Horus^[3][4], 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 "recipe" ^[5], the imperative form of "recipere", "to take or take thus"^[6] and it is quite possible that more than one of these factors influenced its form. Literally, "Recipe" means simply "Take...." and when a medical practitioner writes a prescription beginning with "Rx", he or she is completing the command. This was probably originally directed at the pharmacist who needed to take a certain amount of each ingredient to compound the medicine, 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".

[edit] Contents

Both pharmacists and prescribers are regulated professions in most jurisdictions. A prescription as a communications mechanism between them is also regulated and is a legal document. Regulations may define what constitutes a prescription, the contents and format of the prescription (including the size of the piece of paper.^[7]) and how prescriptions are handled and stored by the pharmacist. Many jurisdictions will now allow faxed or phone prescriptions containing the same information.^[8]

Drug companies use direct-to-prescriber advertising in an effort to convince prescribers to dispense as written with brand-name products rather than generic drugs.

Many brand name drugs have less expensive generic drug substitutes that are therapeutically equivalent. Prescriptions will also contain instructions on whether the prescriber 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 "substitution permitted" underneath. Some have a preprinted box "dispense as written" for the prescriber to check off (but this is easily checked off by anyone with access to the prescription). Other jurisdictions the protocol is for the prescriber to handwrite one of the following phrases: "dispense as written", "DAW", "brand necessary", "do not substitute", "no substitution", "medically necessary", "do not interchange".^[9] In other jurisdictions may they use completely different languages, never mind a different formula of words.

In some jurisdictions, it may be a legal requirement to include the age of child on the prescription.^[10] For pediatric prescriptions some advise the inclusion of 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.) Adding the weight of the child is also helpful.

Prescriptions often have a "label" box.^[11] 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 prescribers 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 medical practitioner. Regulations may restrict some types of drugs from being refilled.

In group practices, the preprinted portion of the prescription may contain multiple prescribers' names. Prescribers typically circle themselves to indicate who is prescribing or there may be a checkbox next to their name.

[edit] Handling

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.^[12] 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.

When filled by the pharmacist, prescriptions are typically assigned a "prescription number" (often abbreviated "Rx#" in the US) 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. Often the patient cannot take the original prescription with them. Some jurisdictions may entitle patients to a copy. The retention period varies but can be as long as six years.^[13] 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. For example, if the pharmacy goes out of business, the pharmacist may be required to return the prescription to the patient, to the next closest pharmacy or to the governing body for pharmacists.

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 2002.^[14] This number has grown from 1.5 billion in 1989 and is expected to continue to grow.

[edit] Forgeries and prevention

Prescriptions are sometimes forged because many narcotics are cheaper and safer as prescription drugs than as street drugs. Forgery takes many forms: Prescription pads are sometimes stolen, amounts may be altered on legitimate prescriptions, call back numbers may be falsified and phoned or faxed prescriptions faked.^[15]

Some medical practitioners will use prescription pads that contain similar security measures as checks to make photocopying prescriptions harder. These security measures may be mandated by law.^[7] Legislation may mandate that only certain printers may print prescriptions.^{[16][dead link]}. New Jersey, for example, requires that only state approved printers may be used to print official "New Jersey Prescription Blanks."^{[17][dead link][18]} Prescribers can make it harder for amount forgeries by writing out the amounts in words. Again, this may be mandated by law.^{[19][dead link]}

Wikinews has related news: Canadian woman faces 234 counts of double-doctoring

Some jurisdictions help control stolen prescriptions by requiring special "triplicate prescriptions" for certain classes of drugs.^{[20][dead link]} Blank triplicates are only available from the regulating agency and are individually numbered. The medical practitioner 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 forged prescriptions that pharmacists can check. In this example, the prescription's validity is further limited to 72 hours from issuance. California has recently replaced triplicate forms with new forms that are impossible to photocopy or fax: the background is printed with repetitions of the word void in a color that shows up as black on a photocopy.

States have various laws making theft of prescription blanks or forgery of prescriptions criminal offenses and/or providing special treatment for these offenses (for Example N.J. Stat. 2C:21-1. making forgery of a prescription blank a third degree rather than fourth degree offense).^[21]

When forgery is suspected, pharmacists will call the medical practitioner to verify the prescription. Forged prescriptions are no longer considered medical documents and doctor-patient confidentiality rules no longer apply.

[edit] Writing prescriptions

[edit] Who can write prescriptions

Who can issue prescriptions is governed by local legislation. In the United States medical practitioners, veterinarians, dentists, and podiatrists have prescribing power. In addition, clinical pharmacists are allowed to prescribe in some states through the use of a drug formulary or collaboration agreements. In all states, optometrists prescribe medications to treat certain eye diseases, and also issue spectacle and contact lens prescriptions for corrective eyewear.^[22] States allow registered certified physician assistants (also known as physician associates or PAs) prescription powers in all 50 states. Several states have passed RxP legislation, allowing clinical psychologists (PhD's or PsyD's) who are registered as medical psychologists and have also undergone specialized training in script-writing to prescribe a limited number of drugs to treat emotional and mental disorders.

[edit] Legibility

Prescriptions, when handwritten, are notorious for being often illegible . In the US, medical practitioners' sloppy handwriting kills more than 7,000 people annually, according to a July 2006 report from the National Academies of Science's Institute of Medicine (IOM).^[23] Historically, physicians used Latin words and abbreviations to convey the entire prescription to the pharmacist. Today, many of the abbreviations are still widely used and must be understood to interpret prescriptions. 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. When in doubt, pharmacists call the medical practitioner. Some jurisdictions have legislated legible prescriptions (e.g. Florida^[24]). Some have advocated the elimination of handwritten prescriptions altogether,^[25] and computer printed prescriptions are becoming increasingly common in some places.

[edit] Conventions for avoiding ambiguity

Over the years, prescribers have developed many conventions for prescription-writing, with the goal of avoiding ambiguities or misinterpretation.^{[26] [27] [28]} These include:

• Careful use of decimal points to avoid ambiguity:
  • Avoiding unnecessary decimal points: a prescription will be written as 5 mL instead of 5.0 mL to avoid possible misinterpretation of 5.0 as 50.
  • Always using zero prefix decimals: e.g. 0.5 instead of .5 to avoid misinterpretation of .5 as 5.
  • Avoiding trailing zeros on decimals: e.g. 0.5 instead of .50 to avoid misinterpretation of .50 as 50.
  • Avoiding decimals altogether by changing the units: 0.5 g is less easily confused when written as 500 mg.
• "mL" is used instead of "cc" or "cm³" even though they are technically equivalent to avoid misinterpretation of 'c' as '0' or the common medical abbreviation for "with" (the Latin "cum"), which is written as a 'c' with a bar above the letter. Further, cc could be misinterpreted as "c.c.", which is an uncommonly used abbreviation for "take with meals" (the Latin "cum cibum").
• Directions written out in full in English (although some common Latin abbreviations are listed below).
• Quantities given directly or implied by the frequency and duration of the directions.
• Where the directions are "as needed", the quantity should always be specified.
• Where possible, usage directions should specify times (7 am, 3 pm, 11 pm) rather than simply frequency (3 times a day) and especially relationship to meals for orally consumed medication.
• The use of permanent ink.
• Avoiding unspecified prn or "as needed" instructions—instead, specific limits and indicators are provided e.g. "every 3 hours prn pain."
• For refills, the minimum duration between repeats and number of repeats should be specified.
• Providing the indication for all prescriptions even when obvious to the prescriber, so that the pharmacist may identify possible errors.
• Avoiding units such as "teaspoons" or "tablespoons."
• Writing out numbers as words and numerals ("dispense #30 (thirty)") as in a bank draft or cheque.
• The use of apothecary/avoirdupois units and symbols of measure -- pints (O), ounces (℥), drams (ℨ), scruples (℈), grains (gr), and minims (♏) -- is discouraged given the potential for confusion. For example, the abbreviation for a grain ("gr") can be confused with the gram, abbreviated g, and the symbol for minims (♏), which looks almost identical to an 'm', can be confused with micrograms or meters. Also, the symbols for ounce (℥) and dram (ℨ) can easily be confused with the numeral '3', and the symbol for pint (O) can be easily read as a '0'. Given the potential for errors, metric equivalents should always be used.
• The use of the degree symbol (°), which is commonly used as an abbreviation for hours (e.g., "q 2-4°" for every 2 - 4 hours), should not be used, since it can be confused with a '0'. Further, the use of the degree symbol for primary, secondary, and tertiary (1°, 2°, and 3°) is discouraged, since the former could be confused with quantities (i.e. 10, 20 and 30, respectively).

[edit] Abbreviations

See list of abbreviations used in medical 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.

Some abbreviations which are ambiguous, or which in their written form might be confused with something else, are not recommended and should be avoided. These are included in a separate list in Appendix 1. However, all abbreviations carry an increased risk for confusion and misinterpretation and should be used cautiously.

[edit] Non-prescription drug prescriptions

Prescriptions are also used for things that are not strictly regulated as a prescription drug. Prescribers 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 medical practitioner. Conversely, if a medication is available over-the-counter, prescribers may ask patients if they want it as a prescription or purchase it themselves. Pharmacists may or may not be able to price the medication competitively with over-the-counter equivalents. If the patient wants the medication not under prescription, the prescriber is usually careful to give the medication 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 prescriber as a prescription.

Prescribers will often use blank prescriptions as general letterhead. Legislation may define certain equipment as "prescription devices".^[29] 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 prostheses, gut sutures, sickle cell tests, cervical cap and ultrasound monitor.

In some jurisdictions, hypodermic syringes are in a special class of their own, regulated as illicit drug use accessories,^[30] separate from regular medical legislation. Such legislation will often specify a prescription as the means by which one may legally possess syringes.

[edit] 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. In reference to the entire system of controlling drug distribution (as opposed to illicit drugs), "prescription" is often used as a metaphor for healthy directions from a prescribing medical practitioner. A "green prescription" is direction from a medical practitioner to a patient for exercise and healthy diet.

[edit] History

The concept of prescriptions dates 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.^[31]

Modern prescriptions are actually "extemporaneous prescriptions" from the Latin (ex tempore) for "at/from time".^[32] "Extemporaneous" means the prescription is written on the spot for a specific patient with a specific ailment. This is distinguished from 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.^[33] 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".^[34]

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 the imperative "take." This is an exhortation to the pharmacist by the medical practitioner, "I want the patient to have the following medication"^[35] - in other words, "take the following components and compound this medication for the patient."

The inscription section defines what is the medication. The inscription section is further composed of one or more of:^[36]

• 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.

The "signature" section contains directions to the patient ,^[37] and is often abbreviated "Sig." ^[38] or "Signa." It also obviously contains the signature of the prescribing medical practitioner though the word "signature" has two distinct meanings here and the abbreviations are sometimes used to avoid confusion.

Thus sample prescriptions in modern textbooks are often presented as:

Rx:  medication
Disp.:  dispensing instructions
Sig.: patient instructions

[edit] Use of Technology

As a prescription is nothing more than information among a prescriber, 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 prescriber to the pharmacist using smartcard or the internet.^[39] In the United Kingdom a project called the Electronic Transfer of Prescriptions (ETP) within the National Programme for IT (NPfIT) is currently piloting such a scheme between prescribers and pharmacies.

Within computerized pharmacies, the information on paper prescriptions is recorded into a database. Afterward, the paper prescription is archived for storage and legal reasons.

A pharmacy chain is often linked together through corporate headquarters with computer networking. Walgreens, for example, uses satellite technology to share patient information. A person who has a prescription filled at one Walgreens can get a refill of that prescription at any other store in the chain, as well as have their information available for new prescriptions at any Walgreens.

Some online pharmacies also offer services to customers over the internet. Walgreens' web site, for example, allows customers to order refills for medicine over the internet, and allows them to specify the store that they will pick up the medicine from. Their web site also allows consumers to lookup their prescription history, and to print it out.

Many pharmacies now offer services to ship prescription refills right to the patient's home. CVS, for example, will ship refills free of charge. They also offer mail service where you can mail in a new, original prescription and a signed document, and they will ship the filled prescription back to you.

Pharmacy information systems are a potential source of valuable information for pharmaceutical companies as it contains information about the prescriber's prescribing habits. Prescription data mining of such data is a developing, specialized field.^[40]

Many prescribers lack the digitized information systems that reduce prescribing errors.^[41] To reduce these errors, some investigators have developed modified prescription forms that prompt the prescriber to provide all the desired elements of a good prescription. The modified forms also contain pre-defined choices such as common quantities, units and frequencies that the prescriber may circle rather than write out. Such forms are thought to reduce errors, especially omission and handwriting errors and are actively under evaluation. (See: Kennedy AG, Littenberg B. A Modified Outpatient Prescription Form to Reduce Prescription Errors. Joint Commission Journal of Quality and Safety 2004; 30:480-487.)

[edit] Notes

[edit] References

[edit] See also

• Eyeglass prescription
• List of abbreviations used in medical prescriptions
• Off-label use
• Prescription drugs
• Private prescription