prescription

Meaning of prescription: Part instruction and part legal document, a prescription records exactly what was ordered and by whom, and stays in the record long afterward.

Definition of prescription

A prescription is an order from a licensed prescriber authorizing a specific medication or other treatment for a named patient. It sets out what is being given, how much, by which route, how often and for how long, and it carries the prescriber's identification. Written on paper or sent electronically, it works as both an instruction to the pharmacy and a legal record.

What is written on one?

ElementWhat it states
Patient detailsName and identifiers, and age or weight where the amount depends on them
Drug, strength and formWhich medicine, at what strength, as tablet, liquid, cream or injection
DirectionsAmount per administration, route and frequency, traditionally called the sig
Quantity and repeatsHow much to supply and whether it may be supplied again
Prescriber detailsName, registration number, signature and date

The directions are still often abbreviated from Latin: po for by mouth, bd or bid for twice a day, prn for as needed. Many services now discourage these, because several of them look alike in handwriting and have been mistaken for one another.

Who is allowed to write one?

Physicians and dentists prescribe almost everywhere. Beyond that the rules differ by country and often by region within a country. Nurse practitioners, pharmacists, physician associates, optometrists, podiatrists and midwives hold prescribing rights in some places and not others, sometimes restricted to a defined list of medicines. Veterinarians prescribe for animals. The common thread is a license that carries personal accountability for the decision, which is what separates a prescription written by a clinician from a recommendation made by anyone else.

How does prescription only differ from over the counter?

A prescription only medicine is one a regulator has judged to need professional oversight. The reasons vary: the condition is hard to identify without training, the gap between a useful and a harmful amount is narrow, the drug interacts with many others, or its use has to be monitored. Products sold over the counter have passed a different test. The line between the two is not fixed. Medicines move onto open sale once enough is known about them, and the same drug can require a prescription in one country and sit on a shelf in another. A middle tier exists in many places, kept behind the counter and supplied after a conversation with a pharmacist.

What happens once it is written?

The pharmacy checks the order before filling it, against the person's other medicines for interactions, against the usual amounts for that drug, and against what has already been supplied. That review acts as a second check on the prescribing decision, and a query back to the prescriber is a routine part of it rather than a sign of error. Once filled, the prescription remains in the record. It shows what has been taken and for how long, which matters when a new medication is added, when a reaction has to be explained, or when care passes to another service.

Used in a sentence

The physician wrote a prescription for a course of antibiotics.

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Good to know

A prescription differs from an over the counter product in requiring authorization from a licensed prescriber, which reflects a judgment that the medicine needs professional oversight rather than that it is necessarily stronger.

Word origin

Where “prescription” comes from

From Latin praescriptio, formed from prae- meaning before and scribere meaning to write, so literally something set down in advance.

For learning, not diagnosis. This glossary provides general educational information and is not a substitute for advice from a qualified healthcare professional. If you may be experiencing a medical emergency, contact local emergency services.