Prescription Writing 101 for Medical Students

Marc Imhotep Cray, M.D.
2
 Identify required elements of a prescription
(noncontrolled substances).
 Identify dangerous abbreviations that should
be avoided.
 Identify common prescription writing errors.
 Demonstrate an ability to write a correct
hand written prescription.

3
Historically, writing prescriptions is not well covered in
medical school may be one of reasons for so many
medication errors in medicine ?
Some commonly quoted statistics include:
 Medication errors occur in approximately 1 in every 5 doses
given in hospitals
 One error occurs per patient per day
 1.3 million people are injured and approx. 7,000 deaths occur
each year in U.S. from medication-related errors
 Drug-related morbidity and mortality is estimated to cost $177
billion in U.S.
 If there are 800,000 physicians in U.S, each physician accounts
for $221,250!  1 reason why malpractice insurance is so
expensive?

4
A prescription is an order written by you, the physician
(or medical student w signature by a physician) to tell
pharmacist what medication you want your pt. to take
 Basic format of a prescription includes patient’s name and
another patient identifier, usually date of birth
 It also includes meat of Rx
o Medication and strength,
o Amount to be taken,
o Route by which it is to be taken and
o Frequency
o For “as needed” medications, there is a symptom included
for when it is to be taken
o Prescriber also writes how much should be given, and
how many refills

5
Certain elements should be included in every Rx,
whether a noncontrolled or controlled substance
Basic elements include following:
 Date the prescription was written
 Prescriber identification
 Patient identification
 The inscription
 The subscription
 Signa
 Indication
 Refill information
 Generic substitution
 Warnings
 Container information
 Prescriber’s signature

Following, we will briefly discuss each of the 11
basic elements of the Rx (as per U.S standards )
listed in the previous slide.
6

7
In many cases, this is preprinted on a
standard prescription form
 Includes name and title of prescriber and address
and telephone number of practice or institution
 When prescriber is a nonphysician some states
in U.S. require supervising physician’s name be
printed on Rx form as well

8
This includes patient’s name, address, age or date of
birth, and sometimes, weight
 Recommended (and in some states required) that you use
patient’s legal name instead of a nickname
o If you are unsure of pt’s legal name, ask to see a driver’s
license or an insurance card if available
• This helps avoid confusion & correctly identifies pt.
 Date of birth (DOB) is more commonly requested than
patient’s age b/c it allows more specific identification
 When a Rx is written for a pediatric patient, you should
include patient’s weight so pharmacist can verify medication
has been dosed appropriately

9
This includes name and strength of Medication
 Generic or trade names may be used
Avoid abbreviating names of medications to help
reduce possibility of error
 There are exceptions for well-known
medications for example, trimethoprim-
sulfamethoxazole is commonly abbrev. TMP/SMX
 Strength= amount per dosing unit, such as a 50 mg
tablet or 250 mg per 5 mL

10
Some meds come in many different
strengths and forms (i.e., tablets and
liquids)
 If you are unsure which strengths and forms
are available you should consult a
prescribing guide, pharmacology text, or
medication reference formulary
NB: Strength is not same as total amount
to be taken by patient over course of
prescription

11
This provides information to pharmacist on
dosage form and number of units or doses to
dispense
 Instructions about dosage form may be tablets,
capsules, or suspension, for example
 If a liquid or semiliquid is to be dispensed
provide quantity, such as how many milliliters
of suspension or how many grams in a tube

12
 Amount dispensed should be amt.
needed to complete a course of
treatment
 For example, if a pt. is to take a tablet
twice a day for 10 days subscription, or
amount to dispense, would be 20 tablets
o You will often see #20 or Disp: 20 tabs
either is acceptable

13
This provides instructions to patient on how
to take medication and should be as specific
as possible It should include:
 route
 any special instructions, such as to take on an
empty stomach or with food, and
 how often to take
 When medication is Rx on a prn basis reason for
taking med. should be included
NB: Avoid writing vague or ambiguous instructions,
such as take as directed or apply in usual manner

14
Numerous studies have documented pts
usually do not remember all information
they are given during course of a doctor–
patient encounter
 therefore, it is necessary to provide instructions
that are as detailed and accurate as possible
to reduce chance medication may be taken
inappropriately

15
 Frequency is simply how often you want
prescription to be taken
 This can be anywhere from once a day, once a night, twice
a day or even once every other week
 Many frequencies start with letter “q” Q if from
Latin word quaque which means once
 So it used to be that if you wanted a medication to be
taken once daily, you would write QD, for “once daily” (“d”
is from “die,” Latin word for day)
 However, to help reduce medication errors, QD and QOD
(every other day) are on the JCAHO* “do not use” list.
Instead you need to write “daily” or “every other day.”
*Joint Commission on Accreditation of Healthcare Organizations

16
Common Route Abbreviations:
 PO (by mouth)
 PR (per rectum)
 IM (intramuscular)
 IV (intravenous)
 ID (intradermal)
 IN (intranasal)
 TP (topical)
 SL (sublingual)
 BUCC (buccal)
 IP (intraperitoneal)
Common Frequencies Abbreviations:
 daily (no abbreviation)
 every other day (no abbreviation)
 BID/b.i.d. (Twice a Day)
 TID/t.id. (Three Times a Day)
 QID/q.i.d. (Four Times a Day)
 QHS (Every Bedtime)
 Q4h (Every 4 hours)
 Q4-6h (Every 4 to 6 hours)
 QWK (Every Week)

17
 U or u (unit) – use “unit”
 IU (International unit) – use “International Unit”
 Q.D./QD/q.d./qd – use “daily”
 Q.O.D./QOD/q.o.d./qod – use “every other day”
 Trailing zeros (#.0 mg) – use # mg
 Lack of leading zero (.#) – use 0.# mg
 MS – use “morphine sulfate” or “magnesium sulfate”
 MS04 and MgSO4 – use “morphine sulfate” or
“magnesium sulfate”
http://www.jointcommission.org/assets/1/18/Do_Not_Use_List.pdf

18
Including indication for prescription is
mandatory in some U.S. states
 Even when states do not require an indication,
Institute for Safe Medication Practices (ISMP)
recommends including it for two reasons:
 First, many drugs have names that look and sound alike
 Second, illegible writing may cause confusion or
misinterpretation
 Including indication for prescribed medication
provides another safety check for the
prescriber, the pharmacist, and the patient

19
This should be included on prescription
form & can be written as number of times a
prescription may be refilled or a period
during which Rx may be refilled
Most U.S. states impose a 1-year maximal
refill period
 Pts taking medications for chronic conditions
should be assessed at least annually so it is
not prudent to write medication refills for more
than a 1-year period

20
Most Rx forms will allow you to indicate
whether medication should be dispensed as
written (DAW) or if substitution of a generic
form of medication is permitted
Generic medications usually offer
considerable cost savings to pt., and with few
exceptions, it is preferable to allow
substitution

21
Prescription should specify what, if any,
warning labels should be attached to
medication package or vial
In most cases, pharmacist filling Rx will
automatically affix appropriate warnings listed
in prescribing information but prescriber
should include this information on form
 This provides another safety check between
prescriber and pharmacist

22
Item Description
Date of Prescription
Prescriber’s Information Name and title, office or institution name, address, and phone
number, blank line for DEA number
Patient’s Information Legal name, age or date of birth, address, weight if necessary
Inscription Name of drug and strength
Subscription Information for pharmacist regarding dosage form and number
of doses to dispense
Signa Instructions to patients including route of administration, how
often to take, special instructions, or indication for medication
Refill information Number of refills or length of time prescription may be filled
Generic substitution Indicate if a generic form is permissible or if medication is to be
dispensed as written
Warnings What adverse effects may be caused by medication, such as
drowsiness, feeling shaky, etc.
Container information Use of childproof containers is required unless specifically
indicated to use non-childproof container
Provider’s signature and title

23
From http://medicalschoolhq.net/prescription-writing-101/

24
This example is a common medication prescribed when people are leaving
the hospital. It is one 100 mg tablet, taken at bedtime. The Rx is for 30 pills
and no refills.
 Zofran is a anti-nausea
medication used after
surgery
 You’ll notice this script is
missing “amount” IV
medications are a little
different in that amt and
strength are kind of mixed
together
 an “as needed” or “PRN”
medication. When the
patient complains of
nausea, the nurse can give
From http://medicalschoolhq.net/prescription-writing-101/

25
 This example shows a common
way to write prescriptions for
liquids, especially for children
• Obviously “liquid” isn’t the
med, but you get idea
 Liquids come in specific strengths
per amount of liquid
 Here, strength is 10 mg per 5 mL
 We only want to give 5 mg
though, so the “amount” that we
prescribe is only 2.5 mL per dose
 It’s given by mouth every 4 hours
 We are dispensing “1 (one) bottle”
 You could also just write “1 (one)”
as pharmacist would know what
you meant From http://medicalschoolhq.net/prescription-writing-101/

26
THE END
See next slide for companion learning tools.

27
Prescription Writing 101 notes.pdf
Medicines Prescription, Prescribing, Dispensing, and Counseling notes.pdf
(Specific to Ethiopia)
ETHIOPIAN MEDICINES FORMULARY 2nd Ed. 2013. Addis Ababa, Ethiopia.
Medicines: Good Prescribing Practices (GPP)” Manual 2012 Edition.
The Food, Medicine and Health Care Administration and Control Authority
(FMHACA) of Ethiopia.

Prescription Writing 101 for Medical Students

More Related Content

What's hot

Similar to Prescription Writing 101 for Medical Students

More from Imhotep Virtual Medical School

Recently uploaded

Prescription Writing 101 for Medical Students