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 prescriber to pharmacy and 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 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.

b.i.d., t.i.d., etc.

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

Quantity + route of administration + frequency + other

Example Sig:	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 into 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:

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 hours, every six hours, every eight hours, every twelve 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
INH - Inhale
PV - Per vagina or vaginally
PR - Per rectum or rectally
Opth - Ophthalmic (eye)
Otic - Ear

Also, you will find important pharmacy abbreviations under the Medication Terminology section below.

Roman Numerals

Roman numerals are sometimes used in pharmacy, although not regularly, in place of numbers. Here are the Roman numerals and their number values:

SS—\(\frac{1}{2}\)
I (i)—one
V (v)—five
X (x)—ten
L—fifty
C—one hundred
D—five hundred
M—one thousand

These Roman numerals can be placed together to make additional numbers, like II or ii for 2 and LV for 55. It is important to note that a lesser Roman numeral placed before another means subtraction, while a lesser numeral placed after another means addition. For example: IV equals 4, while VI equals 6. Another example: XLI equals 41, while LXI equals 61.

Medical Terminology

Medical terminology is used quite frequently in the healthcare system, which includes 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.

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. Be sure to do your homework and write out a list of basic medical terms, which can be done with a simple search engine search.

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 processing of prescriptions that much easier.

Below is a basic 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		ATC	Around the clock
UD	As directed		NR	No refill
C	With		DAW	Dispense as written
AC, PC	Before meals, after meals		D/C	Discontinue
NPO	Nothing by mouth		Diag	Diagnosis
Preop, postop	Before surgery, after surgery		Disp	Dispense
N/S	Normal saline		D5W	Dextrose 5% in water

As stated above, this is just a basic list of important abbreviations a pharmacy technician should be familiar with. More comprehensive lists may be available online using a simple web engine search. Also, be sure to freshen up on units of measure and what their associated abbreviations (mL—milliliter, mcg—microgram, tsp—teaspoon [5 mL], Tbsp—tablespoon [15 mL], lb—pound, qt—quart, L—liter, etc.).

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.

Days supply

As mentioned in other modules, days supply (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 as “x7D”, which means for 7 days, “x3Mon”, which means for 3 months, or “until gone”, which means until the entire quantity is finished. In many cases, the prescriber will not list a days supply on a prescription if the medication is a maintenance medication. This means the patient will be 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 seen. However, a suspension or liquid quantity is typically written in mLs (milliliters) while most creams and ointments are written in gms (grams). With regard to solutions, quantity will be written in mLs 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 (1 tablet or 2 patches) or be expressed as a weight or volume. 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 1-2 grams topically to the affected joint every 4-6 hours as needed. Eye and ear solutions are dosed by the amount of drops (gtts). Oral solutions are typically dosed in mLs; however, sometimes they will be dosed using other standardized units like teaspoon or tablespoon. It is important to note how many mLs are in a teaspoon (5 mL) and tablespoon (15 mL) as oral syringes are calibrated with measurement marks listed in mLs.

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 comes commercially available in a concentration of 10mg/5 mL in addition to a concentrated formulation of 100mg/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 5 mg/gm. Amoxicillin comes as a 400 mg/5 mL oral suspension, while azithromycin comes in a 200 mg/5 mL oral suspension.

It is important to know the units of measure and how to convert from one to another (grams to milligrams, milligrams to micrograms, percentage to mg/gm, etc.). In the event a prescriber writes a prescription for levothyroxine 0.075 mg, you will know to use levothyroxine 75 mcg for prescription data entry and processing. Another example: if a prescriber writes for morphine concentrate oral solution 20 mg/mL, you know to select the morphine concentrate oral solution 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 x Quantity 1 = Concentration 2 x Quantity 2

For example, your pharmacy has an abundance of lidocaine 5% and the pharmacist on duty wants you to make 1000 mL of lidocaine 2%. How much lidocaine 5% is needed, using a compatible solvent?

\[5 \ \% \times x = 2 \ \% \times 1000 \ mL\] \[0.05x = 20 \ mL\] \[x = \dfrac{20 \ mL}{0.05}\] \[x = 400 mL\]

So, 400 mL of lidocaine 5% is needed to make 1000 mL of lidocaine 2%. But how much solvent is needed to dilute it? Final quantity - calculated quantity = solvent needed. In this case:

\[1000 \ mL - 400 \ mL = 600 \ mL\]