Principles of prescription

writingBalakrishnan

S

Lets introspect......

No. with Department not written 71%No. of drugs per prescription: 2.32No. of drugs by generic: 26.8%No. of drugs by brand name: 73.2%No. with name and designation not written 80.6%No. with doses not clear 47.6%No. with duration not written 53% No. Drugs not dispensed 5.8%

What is a prescription?

Drug prescription – A written or verbal order for a medication by a licensed individual(physician, dentist, veterinarian,etc)

History

• Prescriptions have been in use since ancient times– Latin adopted as

standard language– “Rx” = prescription– “Sig.” = directions

Four common types of prescription:

1. Prescriptions in general practice

2. Hospital prescriptions for in-patients

3. Hospital prescriptions for a non hospital

pharmacy

4. Private prescriptions

General Drug Information

Proprietary vs. nonproprietary

Single vs. compound

Dosage

Parts of the prescription:

1) Superscription: Rx

Also includes the patient details

2) Inscription: Ingredients, Quantity of each used

3)Subscription:Directions to the dispenserDirections to the patientSignature of the prescriberDate of writing the prescription

Following information must be given on a Prescription:1)      Date 2)      Identification of the patient 3)      Formulation of the drug – egTablets - tab Capsule – cap Syrup – syr Suspension – susp Injection – InjMetered dose inhaler – as such Lotion – as such

Rules for writing quantity of drug:

a)Quantities of 1 gram or more should be written in grams. For example, write 2 g.

b) Quantities less than 1 gram but more than 1 milligram should be written in Milligrams For eg, write 100 mg, not 0.1 g

c) 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 eg. write 100 micrograms, not 0.1 mg, nor 100 mcg, nor 100 μg

d) If a decimal point cannot be avoided for values under 1, write a zero before it, for example write 0.5ml not .5ml

Rules for writing quantity of drug:

e) Use ml or mL for milliliters

f) For liquid oral medicines: The dose should be

stated as the number of milligrams in either 5 ml or

10ml, Since these are readily measured amounts, &

special spoons are provided to patients for the

measurements.

Rules for writing quantity of drug:

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.

 

Frequency of administration :

Should be clearly indicatedAtenolol 100mg once daily

Amoxicillin 250mg t.d.s.

(Accepted abbreviations may be used! BUT DO NOT USE)

- Tell the patient what you mean be these times a day/ four times a day!

Route & method of administration:- should be clearly indicated.

Amount to be supplied

Any caution / warning

Model Prescription

1) Name: ABC 2) Date: 31.07.07

3) Age: 70yrs. 4) Sex: male

5) Address: 20, III Cross, Eswaran koil st. Pondicherry 605 002

6) PIMS No: 0298298

7) Diagnosis: Idiopathic Parkinsonism

Model Prescription

8) Rx

9) Tab Levodopa 100mg Tab Carbidopa 25mg10) Dispense 100 combination tablets11) Take 2 tablets by mouth3 times daily with breakfast, lunch and dinner. Take with food. 12) Dr. Sathya MD 13) Assistant Prof. Neurology, 14) PIMS, Pondicherry 605 014 15) Ph: 0413-2207654 16) Reg. No. 34523 17) (TN medical council)

Look Alike/Sound Alike Names

CASE # 1:Serzone (nefazodone) vs. Seroquel (quetiapine)

(antidepressant) (antipsychotic)

• Similar overlapping strengths (100 mg and 200 mg)

• Similar dosage forms (tablets)• Similar dosing interval (BID)• Similar titration schedule• Often stocked in close proximity on pharmacy

shelf

Prescribing and dispensing errors have led to a number of

adverse events (N/V, hallucinations, AMS, lethargy,seizures, death)

Abbreviation Potential Problem Preferred Term

U (unit) Mistaken as zero, four, or cc Write “unit”

IU (international unit) Mistaken as IV or 10 Write “international unit”

Q.D., Q.O.D. Mistaken for each other. Period after Q and O after Q can be mistaken for “I”

Write “daily” and “every other day”

Trailing zero and lack of leading zero

Decimal point missed Never write a zero by itself after a decimal point, and always use a zero before a decimal point

MS, MSO4, MgSO4 Confused for one another Write “morphine sulfate” or “magnesium sulfate”

List of dangerous abbreviations, acronyms, and symbols

List of additional dangerous abbreviations, acronyms, and symbols

ABBREVIATON POTENTIAL PROMBLEM PREFERRED TERM

µg (microgram) Mistaken for mg (milligram) Write “microgram”

H.S. (at bedtime or half – strength)

Mistaken for either meaning: Also mistaken for every hour

Write out “half – strength” or “at bedtime”

T.I.W (three times a week) Mistaken for three times a day or twice weekly

Write “three times weekly” or “3 times weekly”

S.C. or S.Q. (subcutaneous) Mistaken for SL for sublingual or “5 every”

Write “Sub-Q” or “subQ” or “subcutaneously”

D/C Interpreted as discontine whatever medication follows

(typically discharge meds)

Write “discharge”

c.c. Mistaken for U (units) when poorly written

Write “ml” for milliliters

A.S., A.D., A.U. (Latin abbreviations for left, right, both ears)

O.S., O.D., O.U. (Latin abbreviations for left, right, both eyes)

Mistaken for each other (A.S. for O.S., A.D. for O.D., A.U. for O.U., visa versa)

Write out “left ear” or “right ear” or “both ears”

Write out “left eye” or “right eye” or “both eyes”

??????

Prescription for controlled drugs must(e.g. morphine)

1. Be completely written in the prescriber’s hand

writing in ink

2. Be signed & dated

3. Carry the prescribers’ address

4. Carry the name & address of the patient

5. State the form of the drug

6. State the total quantity of the drug or the number

of dose units to be disposed in both words &

figures

7. State the exact size of each dose in both words &

figure.

DOCTOR’S ORDER SHEER

Patient’s Name: Age / Sex: PIMS No:   DOCTOR INCHARGE:

No DrugsStrength

Dosage

freq

Route

Signature 1 2 3 4 5 6 7 8 9 10

1                               

2                               

3                               

4                               

5                               

6                               

7                               

8                               

9                               

10                               

11                               

12                               

13                               

14                               

15