1. Principles of Prescription Writing

2. Definition
is the prescriber’s order to prepare or dispense a specific treatment ---- usually medication ---- for a specific patient
A written direction for the preparation & administration of a remedy

3. History Prescriptions have been in use since ancient times
Latin adopted as standard language
“Rx” = prescription
(take thou)

4. Aim of Prescription drug
drug that requires a prescription because it is considered potentially harmful if not used under the supervision of a licensed health care practitioner

5. Four common types of prescription:
Prescriptions in general practice
Hospital prescriptions for in-patients
Hospital prescriptions for a non hospital pharmacy
Private prescriptions

6. Prescription writing Steps Make a Specific diagnosis
Consider the Pathophysiological implications of the
diagnosis
Select a specific therapeutic objective
Select a drug of choice
Determine the appropriate dosing regimen
Devise a plan for monitoring the drug’s action & determine an end point for therapy
Plan a program of patient education

7. Outpatient Prescription
Elements
Prescriber’s office information
Name
License classification (Professional degree)
Adress
Office telephone numbers

8. A prescription should begin with the
1- name of the person for whom it is designed
2- the date on which it is written. Then
3- follows the Latin word Recipe, usually abbreviated by the sign Rx, and signifying "Take," or "Take thou;“
4- the names and quantities of the ingredient to be used, which are also expressed in Latin; then the directions to the  compounder, followed by the directions to the patient
5- finally the signature of the prescriber

9. prescription then has four component parts
1-SUPERSCRIPTION—which consists of the
name of the patient for whom it is designed,
the date,
and the sign Rx—signifying "Take thou."

10. 2-INSCRIPTION,—the body of the prescription, consisting of one or more of the following subdivisions,
Basis,—or chief ingredient
Adjuvant,—to assist the action of the basis.
Corrective,—to correct some injurious quality of the other ingredients.
Vehicle or excipient ,—to give it a suitable form.

11. SUBSCRIPTION,—the directions for the compounder, usually expressed in contracted Latin.
SIGNATURE,—the instructions for the administration of the medicine, in English or Latin, followed by the signature of the prescriber.

12. Prescriber’s name license classification
Outpatient Prescription
Prescriber’s name license classification
(Professional degree)
Adress
Office telephone numbers
Prescriber’s office
information
Date
Superscription
Patient’s name
Date
Address
Patients information
Drug name and strength
Quantity
SIG:
Superscription
Inscription &
Subscription
Signatura
REFILL TIMES OR
UNTIL
NO CHILD PROOF CONTAINER
WARNING
PRESCIBER’S SIGNATURE
Presciber’s other identification data

14. Prescription Formatting
Heading
Body
Closing

15. Current Prescription Formatting
Heading
Name, address, and telephone number of the prescriber
sex and age of the patient
Date of the prescription 3

16. Contents of the Prescription
Patient Name and Address
Full first and last name
Middle initial may be helpful
DOB – not required, but will be helpful in further identifying the correct patient to prevent medication errors

17. Current Prescription Formatting
Body
The Rx symbol
Name
dose size or concentration (liquids) of the drug
Amount to be dispensed
Directions to the patient 4

18. Contents of the Prescription
Selecting the drug
Medication Allergies
Availability
Cost

19. Contents of the Prescription
Name of the drug
Multiple drugs per prescription can add to confusion
KEEP IT SIMPLE

20. Contents of the Prescription
Name of the drug
AVOID THE USE OF:
Abbreviations
Many drugs identified with abbreviations
EX: HCT for hydrochlorothiazide, MSO4 for morphine sulfate
Attempts to standardize abbreviations have been unsuccessful

21. Current Prescription Formatting
Closing
Prescriber’s signature
Refill instructions
Generic substitution instructions 5

23. Prescription writing Meaning tab tablet cap capsule PO by mouth PR
Abbreviation
Meaning
tab
tablet
cap
capsule PO
by mouth PR
per rectum SL
sublingual IM
intramuscular IV
intravenous
SC, SQ
subcutaneous
Abbreviation
Meaning
OTC
over-the-counter pc
after meals ac
before meals
prn
when needed q
every
q6h
every 6 hours
qhs
every night at bed time
stat
at once

24. List of abbreviations Tablets - tab Capsule – cap Syrup – syr
Suspension – susp
Injection – Inj
Metered dose inhaler – as such
Lotion – as such

25. Contents of the Prescription
Strength of the drug
Be familiar with drugs and their various dosing strengths and dosage forms
When in doubt, use references

26. Dosing count ; Weight – based dosing
Always convert patient weight to correct units (kg)
Liquid medications
One product may be available in a number of concentrations
Be familiar with various product concentrations
Indicate BOTH concentration and dose of medication
Example: Cephalexin suspension 125 mg/ 5 ml
1 teaspoon/ every 8 h

27. Poor presciption writing Other errors
Prescribing errors
Poor presciption writing
Other errors
Error
Misread (Danger)
Correct .1 1
0.1
1.0 10 /
Abandoned
10U
100
10 units IU
10 or 14 µg mg
mcg
Use leading zeros
Never use trailing zeros

28. Contents of the Prescription
Strength of the drug
Decimal points
Avoid trailing zeros.
EX. 5 mg vs mg; can be mistaken for 50 mg
Always use leading zeros.
EX. 0.8 ml vs. .8 ml; can be mistaken for 8 ml

29. Contents of the Prescription
Quantity of the drug
Prescribe only necessary quantity
Write for specific quantities rather than time period (for example: dispense #30 vs. dispense for 1 month)
Calculate: quantity = frequency per day x treatment days

30. Rules for writing quantity of drug:
Quantities of 1 gram or more should be written in grams.
Ex - write 2 g.
Quantities less than 1 gram but more than 1 milligram should be written in Milligrams For eg, write 100 mg, not 0.1 g

31. Quantities less than 1 milligram should be written in micro / nano gram as appropriate.
DO NOT abbreviate micro/ nanograms; since that can lead to Prescribing errors. For EX. write 100 micrograms, not 0.1 mg, nor 100 mcg, nor 100 μg
Use ml or mL for milliliters

32. For some drugs, a maximum dose may need to be stated ( for eg
For some drugs, a maximum dose may need to be stated ( for eg. ergotamine in migraine & colchicine in gout).
Eg: Ergotamine 1 mg at onset of attack & repeat every 30 min if necessary . Do not take more than 6 mg in one day or more than 12mg in one week

33. Contents of the Prescription
Directions for use
Write out in full English or use Latin abbreviations
Latin abbreviations – more convenient, more potential for mistakes
Avoid Dangerous Abbreviations
Provide clear and specific directions

34. Should be clearly indicated
Atenolol 100mg once daily
Amoxicillin 250 mg.
- Tell the patient what you mean be these times a day/ four times a day!

38. DOCTOR’S ORDER SHEER Patient’s Name: Age / Sex: PIMS No:
DOCTOR INCHARGE: No
Drugs
Strength
Dosage
freq
Route
Signature 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

39. Sample Prescription-

40. ??????

41. CASE #1
Poor handwriting contributed to a medication dispensing error that resulted in a patient with depression receiving the antianxiety agent Buspar 10 mg instead of Prozac 10 mg

42. Controlled Substance Schedules
Schedule I
Examples: heroin
1. Potential for abuse High
2. No accepted medical use or
lacks accepted safety
May be used for research purposes by properly registered individuals.

43. Controlled Substance Schedules
Schedule II
Examples: morphine
1. Potential for abuse High.
2. Has a currently accepted medical use
3. Abuse may lead to severe psychological or
physical dependence.

44. Controlled Substance Schedules
Schedule III
Examples: anabolic steroids
1. Abuse potential less than substances in schedule I or schedule II.
2. Has a currently accepted medical use.
3. Abuse may lead to
moderate or low physical dependence or
high psychological dependence.

45. Controlled Substance Schedules
Schedule IV
Examples: Alprazolam
1. Abuse potential less than substances in
schedule III.
2. Has a currently accepted medical use
3. Abuse may lead to
limited physical or psychological dependence
relative to substances in schedule III.

46. Controlled Substance Schedules
Schedule V
Examples: phenobarbital
1. Low potential for abuse relative to schedule IV.
2. Has a currently accepted medical use
3. Some schedule V products may be sold in limited
amounts without a prescription at the discretion
of the pharmacist; however, if a physician wishes
a patient to receive one of these products, it is
preferable to provide a prescription
4. Limited dependence possible

47. Controlled Substance
- All prescriptions must be written in ink; this practice
is compulsory for schedule II drugs
- Date
- Prescriber’s name & address
- Patient’s name, age, & address
- Diagnosis
- No abbreviations
- All doses, number of ampules, tablets, etc. should be
written in words (letters) & in figures (numbers)
- Prescriber’s signature
- Prescription is dispensed once, & is kept by pharmacist

48. -Refill
- Refill prn (refill as needed) --- is not appropriate
- If no refill is desired, “Zero” (not 0) --- should be
written in the refill space
- For schedule II drug no refill
- For schedule III &IV drug ----
not to exceed 5 refills or
6 months after the issue date,
whichever comes first
- For schedule V drug no restriction

49. Dose units dose units can be misinterpreted. This is especially
important in paediatrics and for drugs where there is a wide variation in the dose that
can be administered e.g. opiates• A patient died after receiving an epidural infusion containing 30mg diamorphine in 10mls instead of 3mg in 10mls. The doctor's prescription had been misread.
July )

50. Write the word units in full
• Abbreviation of the word units to IU resulted in the administration of 10-fold
overdoses of insulin when prescriptions for 6IU were misread as 61 units
(PharmJ 2001;267:193)

51. avoiding the need for decimal points wherever
possible. Milligram to microgram conversions can result in 10-fold errors.
• A baby weighing 3.2kg was prescribed 10micrograms/kg of digoxin. When the prescription was written the decimal point was omitted and a dose of 320microgram was prescribed and administered.

52. Write up the following doses in micrograms
Digoxin mg.
Thyroxine 0.05mg
Clonazepam 0.1mg
Ipratropium inhaler 0.02mg per dose
Atropine 0.6mg

55. CASE #2
A hypertensive patient accidentally received Vantin 200 mg instead of Vasotec 20 mg when a pharmacist misread this prescription

56. Prescribing errors commonly involve incorrect doses, illegible details
ordering inappropriate medications
drugs that may react with other medications already being taken

57. for example if a doctor to prescribe bacteriostatic with bactericidal
if a doctor fails to prescribe an antihypertensive drug for someone who could benefit from it.
if a doctor to prescribe bacteriostatic with bactericidal
Allergy: diagnosis and treatment of allergic conditions

64. SUMMARY

65. MAXIMIZE PATIENT SAFETY
ALWAYS write legibly.
ALWAYS space out words and numbers to avoid confusion.
ALWAYS complete medication orders.
AVOID abbreviations.
When in doubt, ask to verify.

66. Contents of the Prescription
Date of the order
Patient Name and Address
Name of the drug
Strength of the drug
Quantity of the drug
Directions for use
Practitioner Name, Address, Telephone number

67. Model Prescription
Name: ABC ) Date:
3) Age: 70yrs ) Sex: male
Diagnosis: Idiopathic Parkinsonism Rx
9) Tab Levodopa 100mg
Tab Carbidopa 25mg
2 tablets by mouth 3 times daily for one month .
Take with food.
Dr. Sathya MD
Assistant Prof. Neurology,
Reg. No