Order Entry and Processing Study Guide for the PTCB Exam

Sig Codes

Sig codes are abbreviations used in the directions section of a prescription to communicate information from the prescriber to the pharmacy. They are typically derived from Latin. In simple terms, sig codes are shorthand abbreviations used on prescriptions to ease the amount of text the prescriber needs to write.

It is important for prescribers to clearly write these codes to minimize error, as the codes can look similar. For instance, QD (code for “once daily”) and QID (code for “four times daily”) could easily be mixed up with sloppy handwriting. As a pharmacy technician, it is important to be familiar with the standard sig codes used in practice, as it will make data entry of prescriptions that much easier.

The sig (directions) of a prescription has a basic format as follows:

quantity + route of administration + frequency + further information

Here are two examples:

Sig:	Meaning
1 TAB PO BID PRN PAIN	Take 1 tablet by mouth twice daily as needed for pain.
1 GTT OU QID	Instill 1 drop in both eyes four times daily.

Again, this is your most basic and simplistic format for a prescription’s sig. As you will see in pharmacy practice, some sigs can be more complex, like a medication taper.

Here is a list of the most common sig codes you should be familiar with, separated by category:

Frequency

QD—once daily
QOD—every other day
QOW—every other week
BID—twice daily
TID—three times daily
QID—four times daily
Q4H/Q6H/Q8H/Q12H—every four/six/eight/12 hours

Route of Administration

PO—by mouth
SL—sublingually (under the tongue)
BUCC—buccally (inside the cheek)
TOP—topically
SC/SUBQ—subcutaneously
IM—intramuscularly
IN—intranasally
IV—intravenously
ID—intradermally
IT—intrathecally (into spinal fluid)
INH—inhalation
PV—per vagina (vaginally)
PR—per rectum (rectally)
opth—ophthalmic (eye)
otic—auricular (ear)

You will find other important pharmacy abbreviations under the Medical Terminology section below.

Roman Numerals

Roman numerals are sometimes used in the pharmacy setting in place of numbers. Here are the Roman numerals and their number values:

I (i)—one
V (v)—five
X (x)—10
L—50
C—100
D—500
M—1,000

Following specific rules, these Roman numerals can be placed together to make additional numbers, like II (or ii) for two and LV for 55. With Roman numerals, you can never have more than three of the same symbol in a row. For instance, to equal eight, you have VIII. However, you can’t write VIIII for nine. We need another rule.

When a lesser Roman numeral is placed before another numeral, that means subtraction, while a lesser numeral placed after another numeral means addition. As such, to get nine, we use X (ten) and place a single I (one) in front of it, which translates to 10 - 1 = 9.

Based on these rules, you should be able to determine what the Roman numeral XII stands for. As you know from above, X is 10, and I is one, and the lesser numerals come after the larger numeral, so we have:

\[10 + 1 + 1 = 12\]

Note: There are no Roman numerals for fractions, but in the pharmacy setting, half (1/2) is represented with SS or ss.

Medical Terminology

Medical terminology is used quite frequently in the healthcare system, which includes the pharmacy. It is used in all forms of communication, like a phone call from a doctor’s office or verbiage on a prescription. It is important for a pharmacy technician to become familiar with and understand basic medical terminology, as it is essential for proper communication.

Be sure to do your homework and write out a list of basic medical terms. Knowing the difference between hypertension (high blood pressure) and hyperlipidemia (high cholesterol) will help you identify the associated medication(s) in the patient’s profile and also allow you to communicate effectively with both patients and other healthcare professionals. .

Here is a list of some common medical conditions with which you should be familiar. You may encounter them in the pharmacy setting, and it would be helpful to know their meanings:

Condition	Meaning
hypertension	high/elevated blood pressure
hypotension	low blood pressure
myocardial infarction	heart attack; decreased or blocked blood flow to the heart
arrhythmia	irregular heartbeat caused by dysregulation of electrical impulses
tachycardia	fast heart rate (>100 beats per minute)
bradycardia	slow heart rate (<60 beats per minute)
atherosclerosis	narrowing of the artery walls due to plaque buildup
angina	chest pain
hypercholesterolemia	high/elevated cholesterol levels in the blood
hypertriglyceridemia	high/elevated triglyceride levels in the blood
CVA	cerebrovascular accident (stroke); caused by loss of blood flow to the brain or hemorrhage (blood vessel rupture)
Parkinson’s disease	movement disorder caused by lack of dopamine
narcolepsy	daytime sleepiness and falling asleep
osteoporosis	weak, brittle, porous bones
bursitis	swelling/inflammation of fluid sacs between joints
osteoarthritis	pain in joints caused by the wearing down of cartilage
gout	build-up of uric acid crystal formations in joints
GERD	gastroesophageal reflux disease; heartburn
dyspepsia	indigestion; discomfort and bloating after eating
ulcerative colitis	inflammation/ulcers in the colon caused by the immune system
Crohn’s disease	inflammation/irritation affecting any portion of the digestive tract
gastritis	inflammation of the stomach lining
peptic ulcer	open sores located in the stomach lining or small intestine
hypothyroidism	low thyroid hormone levels
hyperthyroidism	high/elevated thyroid hormone levels
Graves’ disease	autoimmune disorder causing the thyroid gland to be overactive
Cushing’s syndrome	pituitary gland produces too much of the hormone cortisol
hypocalcemia	low calcium levels in the blood
hyponatremia	low sodium levels in the blood
hypernatremia	high/elevated sodium levels in the blood
hypokalemia	low potassium levels in the blood
hyperkalemia	high/elevated potassium levels in the blood
allergic rhinitis	inflammation/irritation of the nasal membrane
pulmonary edema	build-up of fluid in the lungs caused by heart problems
rosacea	flushing/redness of the skin, typically involving the face
dermatitis	swelling, inflammation, and irritation of the skin
eczema	dry, itchy, bumpy skin; also referred to as atopic dermatitis
impetigo	contagious infection of the skin causing sores and blisters
melanoma	skin cancer identified as dark skin spots
thrush	fungal infection of the mouth and/or throat
BPH	benign prostate hyperplasia; enlarged prostate gland not caused by cancer
PID	pelvic inflammatory disease; infection within the female reproductive system
cystitis	infection of the bladder
Hodgkin lymphoma	cancer that forms in the body’s lymphatic system (e.g., lymph nodes)
varicella-zoster infection	contagious viral infection categorized as chickenpox in adolescents and shingles in adults

Abbreviations

Just like sig codes and medical terminology, knowing healthcare and pharmacy-related abbreviations is essential for effective communication and will also make order entry and the processing of prescriptions that much easier.

Below is a list of some standard abbreviations that should be committed to memory:

Abbreviation	Meaning		Abbreviation	Meaning
Stat	immediately		oint, ung	ointment
PRN	as needed		sol	solution
tab	tablet		sup	suppository
cap	capsule		susp	suspension
AAA	apply to affected area		syr	syrup
amp	ampule		inj	injection
gtt	drop		TDS	transdermal delivery system
OS/OD/OU	left eye/right eye/both eyes		ODT	oral disintegrating tablet
AS/AD/AU	left ear/right ear/both ears		MDI	metered-dose inhaler
AM/PM/HS	morning/evening/bedtime		neb	nebulization
Q	every (or at)		ATC	around the clock
UD	as directed		NR	no refill
C	with		DAW	dispense as written
AC/PC	before meals/after meals		DC	discontinue
NPO	nothing by mouth		diag	diagnosis
pre-op/post-op	before surgery/after surgery		disp	dispense
N/S	normal saline		D5W	dextrose 5% in water

This is just a basic list of important abbreviations a pharmacy technician should be familiar with. Also, be comfortable using and understanding these measurement abbreviations:

Abbreviation	Unit of Measurement
gm	gram
mg	milligram
mcg	microgram
mL	milliliter
L	liter
tsp	teaspoon
tbsp	tablespoon
lb	pound
qt	quart
kg	kilogram
oz	ounce
pt	pint
in	inch
cm	centimeter

Let’s try an example problem.

What does the following sig mean?

1 tab PO QHS PRN insomnia

Solution

Let’s break this down one set of letters at a time. First, we have “tab,” which we know from the above list means “tablet.” So, right away we know the prescription is for one tablet. After that, we have “PO,” which stands for “by mouth.” The “Q” means “every” (or “at”) and the “HS” means “bedtime.” Finally, “PRN” stands for “as needed.”

So, putting that all together, you would read the sig as:

“Take one tablet by mouth at bedtime as needed for insomnia.”

Other Symbols

Other symbols are used in the field of pharmacy to convey information like a medication’s concentration or the quantity of the medication needed to dispense to fulfill a prescription. You will need to be familiar with these symbols along with the sig codes and various medical terms.

Days Supply

A medication’s days supply (abbreviated as “DS”) sometimes must be calculated by the pharmacy technician based on the prescribed quantity and specific directions listed on a prescription. In other instances, days supply may be written using various codes, such as “x7D” (“for seven days”), “x3Mon” (“for three months”), or “until gone” (“until the entire quantity is finished”).

In many cases, the prescriber will not list a day’s supply on a prescription if the medication is a maintenance medication. This means the patient is on the medication long term, with no foreseeable stop date.

Quantity

The quantity of a prescription can be expressed in numerous ways. A prescriber can simply write the number of units (e.g., “30 tablets” or “5 patches”), which is the most basic and frequent way quantities are expressed. However, a suspension or liquid quantity is typically written in milliliters (mL), while most creams and ointments are written in grams (g). With regard to solutions, quantity will be written in milliliters as well, although some prescribers may write “QS” (“quantity sufficient”), which is then based on the specified days’ supply written on the prescription.

Dose

The dose is the amount of medication the patient is supposed to take or use at a certain frequency. It can be written as simply the number of units (e.g., “1 tablet” or “2 patches”) or expressed as a weight or volume. For instance, diclofenac 1% gel is a topical pain medication whose dose is written in grams. A common sig seen for diclofenac 1% gel is as follows: Apply 1-2GM TOP to affected joint q4-6hr prn. This sig translates to, “Apply one to two grams topically to the affected joint every four to six hours as needed.

Eye and ear solutions are dosed by the number of drops (gtt). Oral solutions are typically dosed in milliliters; however, sometimes they will be dosed using other standardized units like teaspoons or tablespoons. It is important to note how many milliliters are in a teaspoon (five) and tablespoon (15), as oral syringes are calibrated with measurement marks listed in milliliters.

Concentration

Concentrations can be expressed in numerous ways, depending on the prescription. However, only certain concentrations of such medications are commercially available. For example, morphine solution is commercially available in a concentration of 10 milligrams per five milliliters (10 mg/5 mL) in addition to a concentrated formulation of 100 milligrams per five milliliters (100 mg/5 mL).

Most creams and ointments come supplied as a percentage concentration. Erythromycin comes in a 0.5% eye ointment, which can also be expressed as a concentration of five milligrams per gram. Amoxicillin comes as a 400 milligrams per five milliliters oral suspension, while azithromycin comes in a 200 milligrams per five milliliters oral suspension.

It is important to know the units of measure and how to convert from one to another (e.g. grams to milligrams, milligrams to micrograms). In the event a prescriber writes a prescription for levothyroxine 0.075 milligram (mg), you will know to use levothyroxine 75 micrograms (mcg) for prescription data entry and processing. Likewise, if a prescriber writes for morphine concentrate oral solution “20 mg/mL,” you know to select the morphine concentrate oral solution 100 milligrams per five milliliters (100 mg/5 mL) commercial product, as the concentration is the same.

Dilutions

A dilution is the process of decreasing the concentration of a solute in a solution. The following formula is used to calculate dilution problems:

Concentration \(1 \,\times\) Quantity \(1 =\) Concentration \(2 \, \times\) Quantity \(2\)

For example, suppose your pharmacy has an abundance of lidocaine 5%, and the pharmacist on duty wants you to make 1,000 milliliters of lidocaine 2%. How much lidocaine 5% is needed using a compatible solvent? It’s just a matter of doing basic math:

\[5\% \times x = 2\% \times 1\text{,}000\text{ mL}\] \[0.05x = 20\text{ mL}\] \[x = \frac{20\text{ mL}}{0.05}\] \[x = 400\text{ mL}\]

So, 400 milliliters of lidocaine 5% is needed to make 1,000 milliliters of lidocaine 2%. But how much solvent is needed to dilute it? To figure that out, we need to subtract the calculated quantity (400) from the final quantity (1,000):

\[1\text{,}000 \text{ mL} - 400 \text{ mL} = 600 \text{ mL}\]