A prescription abbreviation is a short code that tells the person giving a medicine how often to give it, when, and by which route. The best known one is RX itself, the medical abbreviation for prescription, which also works as a common abbreviation for pharmacy on signs and bags.
This hub collects the shorthand you meet on orders, medication lists and hospital records, grouped by the job each term does in a line. Patients can use it to check a discharge list against the bottle, and pharmacy technician and nursing students can use it as a study sheet.
At a glance
Covers
Frequency, timing, route, eye and ear terms, drug shorthandMany come from
Latin phrases such as bis in die and per osWhere you see it
Orders, medication lists, hospital charts and some labelsSafety lists
QD and QOD are do-not-use; D/C and the eye and ear terms are error-proneBest version to follow
The plain words printed on your pharmacy label
How a prescription abbreviation fits into an order
A medication order is built in a fixed sequence: the drug, the strength, the route, the frequency, and sometimes a length of time or a reason. Abbreviations fill the route and frequency slots most often, which is why a short order can look like code.
From a hospital order: "Meclizine 25 mg PO q8h PRN dizziness." Read it as meclizine, 25 milligrams, swallowed, every eight hours, and only if dizziness shows up. It shows the format only; the actual medicine and amount are always set by the prescriber.
On the pharmacy side, staff translate these codes into full sentences before the label is printed. That is why the label on the bottle reads like plain instructions while the order behind it does not.
How often: frequency terms
Frequency shorthand is the group most people search for, and a one letter slip here changes the daily total. Several terms start with Q, which comes from the Latin quaque, meaning every.
| Term | Meaning | Note |
|---|---|---|
| QD | Every day | Do-not-use form; write daily |
| BID | Two times in a day | From bis in die |
| TID | Three doses a day | From ter in die |
| QID | Four doses a day | Often spaced through waking hours |
| QOD | Every second day | Do-not-use form; write every other day |
| QAM | Each morning | Q means every, AM means morning |
| QHS | Every night at bedtime | HS comes from hora somni |
| PRN | Only when needed | Usually paired with a reason, such as for pain |
Related forms include TIW for three times a week and the bare Q followed by a number of hours, such as q8h for every eight hours.
When: timing around meals, sleep and urgency
Timing terms say when a dose falls during the day rather than how many doses there are. They often sit right after a frequency term and change how a schedule works in practice.
| Term | Meaning |
|---|---|
| AC | Ahead of eating; Latin ante cibum |
| PC | Once a meal is finished; Latin post cibum |
| HS | Bedtime dose; may be taken as half strength, so ISMP favors QHS |
| STAT | Right away (statim) |
| ad lib | Freely, as much as wanted (ad libitum) |
Combined forms exist too. ACHS joins the two: a dose or check ahead of each meal plus one at bedtime, a pattern common with blood sugar checks.
Which way in: routes and body sites
Route shorthand tells you whether a medicine is swallowed, placed under the tongue, injected or dropped into an eye or ear. The eye and ear terms come from Latin words for right, left and both, and they get swapped by mistake more often than most shorthand.
Drug names and groups in shorthand
Some abbreviations stand for a medicine or a whole drug class rather than an instruction. They show up most in allergy lists, medication histories and hospital notes.
| Term | Stands for |
|---|---|
| ASA | Aspirin (acetylsalicylic acid) |
| APAP | Acetaminophen |
| PCN | Penicillin, often seen in allergy lists |
| ABX | Antibiotics |
| PPI | Proton pump inhibitor, a stomach acid reducer |
| DOAC | Direct oral anticoagulant, a type of blood thinner |
For allergy shorthand such as NKDA and for chart terms around medicines, see the chart notes hub.
Pharmacy abbreviation list safety points
The Joint Commission bars QD and QOD on orders because each was misread as the other or as QID. ISMP, a medication safety group, lists the eye terms and the ear terms as error-prone, because a single letter separates right from left. For bedtime it advises QHS or qhs rather than HS, which can also mean half strength.
- Read the full words on the label, not the shorthand on a printout.
- Check that the number of doses per day on the label matches what you were told.
- For eye or ear drops, confirm which side before the first dose.
- Ask the pharmacist about anything handwritten or unclear.
These tables describe how shorthand is generally used. Your own schedule is set by the people who prescribe and dispense your medicine, so talk with them before you alter anything.
Frequently asked questions
What is the abbreviation for prescription?
It is Rx, written with a capital R and often a line through its tail. It appears on prescription pads, pharmacy signs and bags.
What does q mean in a prescription?
Q stands for every, from the Latin quaque. It joins a time word, so q4h is every four hours and QAM is every morning.
Why does my label use full words when the order had letters?
Pharmacies convert shorthand into plain instructions so patients can follow them safely. When the bottle and a printout do not match, a quick call to the pharmacy sorts it out.
Which prescription abbreviations should not be used?
The Joint Commission has banned QD for daily and QOD for every other day from orders, together with U and IU for units. The safer choice is to write the words out.
Are pharmacy abbreviations the same everywhere?
Most are widely shared, but some differ by country and by facility. In some places OD means once daily rather than right eye, which is one reason the eye terms are considered error-prone.