Pharmacy Technician Days' Supply Practice & SIG Codes

Vocabulary terms, SIG abbreviations, and mathematical calculation assumptions from the Advanced Pharmacy Technician Days' Supply practice exercises.

Days' Supply Calculation (Variable Range)

The practice rule requiring calculation using the highest dose and shortest interval when a dosing range is given, rounding down to a whole day.

PRN Orders (Classroom Calculation Rule)

Directions indicating 'as needed' use, which are assumed to be taken at maximum possible frequency/dose for classroom days' supply exercises.

Ophthalmic & Otic Drop Factor (Standard Assumption)

The standard conversion factor assumed to be $20\text{ drops/mL}$ for eye and ear drop volume calculations.

U-100 Insulin

A standard insulin concentration containing $100\text{ units/mL}$, calculated assuming no inhaler priming or insulin waste.

PO

A SIG code abbreviation meaning 'by mouth' (per os), used in oral tablet, capsule, and liquid prescriptions.

PRN

A SIG code abbreviation meaning 'as needed' (pro re nata), such as for pain, spasms, nausea, itching, or anxiety.

QD

A SIG code abbreviation meaning 'every day' or 'once daily'.

BID

A SIG code abbreviation meaning 'twice a day' (bis in die), representing $2$ doses per day.

TID

A SIG code abbreviation meaning 'three times a day' (ter in die), representing $3$ doses per day.

QID

A SIG code abbreviation meaning 'four times a day' (quater in die), representing $4$ doses per day.

qAM

A SIG code abbreviation meaning 'every morning'.

qHS

A SIG code abbreviation meaning 'every night at bedtime' (quaque hora somni).

AC

A SIG code abbreviation meaning 'before meals' (ante cibum).

gtt

An abbreviation meaning 'drop' or 'drops' (guttae), commonly used in ophthalmic and otic orders.

OU

An ophthalmic SIG abbreviation meaning 'both eyes' (oculo utro).

OD

An ophthalmic SIG abbreviation meaning 'right eye' (oculo dextro).

OS

An ophthalmic SIG abbreviation meaning 'left eye' (oculo sinistro).

AU

An otic SIG abbreviation meaning 'both ears' (auribus utro).

AD

An otic SIG abbreviation meaning 'right ear' (aure dextra).

AS

An otic SIG abbreviation meaning 'left ear' (aure sinistra).

INH

An abbreviation indicating administration by inhalation, as used with aerosol and powder inhalers.

SC

An abbreviation denoting subcutaneous injection, as prescribed for insulin administration.

ODT

Orally Disintegrating Tablet; a solid dosage form formulated to disintegrate rapidly in the mouth without chewing or water.

HFA

Hydrofluoroalkane; an aerosol propellant formulation used in metered-dose inhalers (e.g., Albuterol HFA, Fluticasone HFA).

MWF

An alternate-schedule abbreviation meaning 'Monday, Wednesday, Friday'.