04 prescription interpretation

8/4/2019 04 Prescription Interpretation

http://slidepdf.com/reader/full/04-prescription-interpretation 1/32

PRESCRIPTIONINTERPRETATION Pharm.D Balsam Alhasan



INTRODUCTION

• Many of the calculations performed in the

pharmacy rely on the pharmacist’s ability to

interpret a prescription. Two significant factors,

in regard to prescription interpretation, are the

METRIC LINE and ROMAN NUMERALS. Most of

the weighing and measuring is done in the

metric system with:



• a. Solids being weighed in the unit of

grams or parts of a gram.

• b. Liquids being measured in milliliters or

parts of milliliters.



METRIC LINE

• The METRIC LINE acts as a decimal point for both

grams and milliliters. The unit gram is indicated if

the substance is a solid and milliliters if the

substance is a liquid.



Question:



NOTE:

• The metric line pertains to grams and milliliters only. Whenany other unit designation follows an amount on theprescription, the metric line must be ignored for thatsubstance. For example:

• (1 gr = 64.8 mg)



Problem Set #1



• Roman numerals are sometimes used in place of Arabic

numbers on a prescription to designate the number of

tablets or the number of fluid ounces of a liquid to be

dispensed. For example:



Abbreviations used in

prescriptions:

• Letters or symbols based on Latin words,

that define rout, frequency, time of

administration, dosage form, name of the

drug or disease or a combination of the

above.



Instructions on the prescription:

• Name of the medication

• Dose of the medication

• How often to take the medication

• When to take the medication

•

How to take the medication

• How many pills or boxes..etc.

• How many refills, if any.



Frequency abb.

• ad lib - freely, as needed

• bid - twice a day

• prn - as needed

•

q – every• q3h - every 3 hours

• q4h - every 4 hours

• qd - every day

• qid - four times a day

• qod - every other day

• tid - three times a day



Time of administration:

• ac - before meals

• hs - at bedtime

• int - between meals

• pc - after meals



Amount or size of dose:

• caps – capsule

• gtt – drops

• I, II, III, or IV- the number of doses (1, 2, 3, or 4)

• mg – milligrams

• ml – milliliters

• ss - one half

• tabs – tablets

• tbsp - tablespoon (15ml)

• tsp - teaspoon (5ml)



Rout of administration/area of

application:• ad - right ear

• al - left ear

• c or o – with

• od - right eye• os - left eye

• ou - both eyes

• po - by mouth

• s or ø – without

• sl – sublingual

• top - apply topically



• Often the abbreviation "sig" will appear

just before the directions on the

prescription. "Sig" is short for the Latin,

signetur, or "let it be labeled."



Common Abbreviations

Abbreviation Meaning Latin

a.c. before food ante cibum

a.d. or AD right ear auris dexter

ad. lib. freely as wanted ad libitum

a.l. left ear aurix laevus

alt. die every other day alternus die

alt. h. every other hour alternus horis

a.m. morning ante meridiem

aq. water aqua

a.s. or AS left ear auris sinister

a.u. or AU each ear auris utro

aurist. ear drops auristillae



b.d. twice a day bis die

b.i.d. twice a day bis in diecap. capsule capsula

div. divide divide

eq.pts. equal parts equalis partis

gtt. drop gutta

h. hour hora

h.s. at bedtime hora somni

Mane in the morning mane

mixt. mixture mixtura

narist. nasal drops naristillae

no. number numero



Nocte at night nocte

O. pint octarius

oc. eye ointment oculentum

o.d. daily omni die

o.d. or OD right eye oculus dexter

o.l. left eye oculus laevus

o.m. in the morning omni mane

o.n. at night omni nocte

o.s. or OS left eye oculus sinister

o.u. or OU each eye oculus utro



p.c. after food post cibum

p.m. afternoon post meridiem

p.o. orally per os

p.r. rectally per rectum

p.r.n. as occasion requires pro re nata

p.v. vaginally per vaginumq.4.h. every 4 hours quaque 4 hora

q.6.h. every 6 hours quaque 6 hora

q.d. or QD every day quaque die

q.d.s. four times a day quater die sumendus

q.i.d. four times a day quater in die

q.o.d or QOD Every other day quaque altera die

q.q.h. every four hours quarta quaque hora



q.s. a sufficient quantity quantum sufficiat

s.i.d. once a day semel in die

Sig. or S. write on the label signa

stat. immediately statim

supp. suppository suppositorum

syr. syrup syrupus

tab. a tablet tabella

t.d.s. three times a day ter die sumendus

t.i.d. three times a day ter in die

ut dict. or u.d. as directed ut dictum

ung. ointment unguentum



Be careful!!!!!!

• Despite their widespread use in prescription writing,

some of them are considered dangerous to use by

Institute of Safe Medication Practices (ISMP) since

they have been found to cause serious medication

errors as a result of misinterpretation. Hence, their

use is discouraged. Problematic Latin abbreviations

are illustrated in the following table:



Abbreviation Intended

Meaning

Misinterpretation Correction

AD, AS, AU Right ear, Left

ear, Each ear

Mistaken as OD,

OS, OU (right eye,

left eye, each eye)

Use "right ear",

"left ear", "each

ear".

OD, OS, OU Right eye, lefteye, each eye

Mistaken as rightear, left ear, each

ear.

Use "right eye","left eye", "each

eye".

HS

hs

Half-strength

at bed-time,

hours of sleep

Mistaken as

bedtimeMistaken as half-

strength

Use "half-

strength"

Use "bedtime"



Abbreviation Intended

Meaning

Misinterpretation Correction

o.d. or OD Once daily Mistaken as "right

eye" (OD Oculus

Dexter) leading to oral

medications given

through the eye

Use "daily"

Per os By mouth, orally "os" can be mistaken

as left eye

Use "PO", "by

mouth" or

"orally".

q.d. or QD Every day Mistaken for q.i.d, Use "daily"

qhs Nightly at bedtime Mistaken as "qhr" or

every hour.

Use nightly.

q.o.d or QOD Every other day Mistaken as "q.d"

(daily) or "q.i.d" (four

times daily)

Use "every

other day"



Problem Set:

• Example 1:

• Simvastatin 40 mg I PO qhs

• Disp. 60 tabs

• Refill =0



Example 2

• Isordil 5mg tab

• I tab S.L PRN q5min up to III tabs.

• Disp. 30 tabs

• Refill = 3



Example 3:

• Diclogesic ear drops:

• III gutt ad qid.

• Disp. 1

• Refill = 0



Example 4

• Voltarin CR 75 mg tabs

• I tab PO bid pc.

• Disp. 30 tabs.

• Refill = 1



Questions?

04 prescription interpretation

Documents