Prescription and Medication Orders


Amoxicillin 250 mg/5 mL susp., 150 ml
t.o. M. Drew, MD / G. Thompson, Pharm.D



TABLE 3.1 Abbreviations for prescribes










































Abbreviation Meaning
ARNP Advanced Registered Nurse Practitioner
CNM Certified Nurse Midwife
DDS Doctor of Dental Surgery
DO Doctor of Osteopathy
DPM Doctor of Podiatric Medicine
DVM Doctor of Veterinary Medicine
MD Medical Doctor
ND Doctor of Naturopathy
OD Doctor of Optometry
PA Physician’s Assistant or “Medex”
Pharm.D Doctor of Pharmacy
RPh Registered Pharmacist

A pharmacist received the prescription below.




(a) What is the profession of the prescriber?


(b) Only 250 mg tablets of Naproxen sodium (generic for Naprosyn®) are available. Would it be correct for the pharmacist to fill the prescription without consulting the prescriber?


(c) How was this prescription ordered (prescription form, telephone order, voice order or computer order)?


Solutions.



(a) A dentist: Doctor of Dental Surgery

(b) Yes, substitution was authorized by the prescriber

(c) The prescription was written by the registered pharmacist of a dentist telephone order.

PRESCRIPTIONS AND MEDICATION ORDERS


Components



2. A prescription is a lawful order of a practitioner for a drug or device for a specific patient. In a more specific sense, it means a written request for the preparation and administration of any medication for an outpatient. A prescription may order a manufactured drug product or a compounded drug product. It may order a wheelchair or a walker. A medication order, drug order or physician’s order is a request for a drug product for inpatients in institutional settings.

Preprinted forms containing information about the prescriber are generally used by practitioners to write prescriptions. Additionally, pharmacists frequently receive prescription orders over the phone, through voice message, through the internet, or by direct communication. Typical medication orders (for inpatient) use different forms, which may be handwritten in ink by the physician, typed or just sent through the institution’s database system.



Writing a Prescription



3. Prevention of medication errors is of utmost importance, and it must start at the time a prescription is written and transcribed/read. Some general recommendations by the USP and NABP to prevent medication errors:


  • Written prescriptions/medication orders must be legible.
  • Prescribers should avoid the use of certain abbreviations (e.g., abbreviations of drug names or combinations of drugs; OD for once daily since OD also stands for right eye; U for units, which may be mistaken for a zero when poorly handwritten).
  • Prescriptions/medication orders should always be written using the metric system.
  • Prescriptions/medication orders should include the drug name, metric weight or concentration, and dosage form. In addition, when transcribing verbal orders or typing medication names keep one space apart each the drug, the units, and the weights.
  • A leading zero should always precede a decimal point in quantities less than one (e.g. 0.5 mg, not .5 mg) and a trailing zero should never be used after a decimal point (1 mg, not 1.0 mg).
  • Numbers above 999 should have properly placed commas (e.g. 500,000 and not 500000).
  • Prescribers should provide the age and, when appropriate, weight of the patient.
  • Prescriptions/medication orders should include, when possible, a notation of purpose of the medication.
  • Prescribers should not use imprecise instructions such as “Take as directed” or “Take as needed”. Orally transmitted directions may be forgotten or misinterpreted. There is also the legal aspect for controlled substances (overdose, mishandling).
  • Phoned prescriptions (and voice orders) should be reduced to writing and/or computer data entry immediately. In addition, the dose and drug strength should be checked by individual numbers as they may sound alike (e.g. “one-five” for fifteen and “five-zero” for fifty).



4. A handwritten medication order received by the hospital pharmacist contained the following:

(1) Penicillin G sodium 100000 U IM q 8h

(2) Clonazepam .75 mg bid

Point out what is wrong in each order.



Solutions.



(1) 100,000 (with comma) and units should be spelled.

(2) The dosage of clonazepam should have a leading zero (0.75). If the decimal point was not seen, a 100 fold overdose would be used. One space is needed between the number and its unit (0.75 mg).



5. A prescription order for a compounded drug product is:















Indomethacin 0.025 g

Fattibase q.s.

M. & Ft. supposit. #6

Sig. Take as directed.

What is incorrectly written or imprecise in this prescription?







Solution. Mistakes can be made when reading numbers less than 1 with decimals: should be written 25 mg.
Abbreviation for suppository is not standard (correct is supp.)
Imprecise instruction in the signa.


Examples of Prescriptions and Medication Orders



6. The illustrations that follow will show some examples of prescriptions and medication orders with their basic components. According to the National Association of Boards of Pharmacy, the minimal recommended legal requirements for outpatient prescriptions are:

1. Prescriber information: name, degree, address, phone number, signature, DEA* registration number.

2. Patient information: name, address, other.

3. Date: date of prescription or date of issue.

4. Superscription: symbol = “take thou”, “you take”, “recipe”.

5. Inscription: the drug product prescribed = name, strength, dosage form of drug product prescribed (manufactured product), or name and quantity of each ingredient (compounded product).

6. Subscription: dispensing instructions to the pharmacist.

7. Signa (Sig.): directions for use by the patient.

8. Special instructions: refills, generic product substitution. For refills, the common interpretation for absence of information is that zero refills are authorized.

Prescription order for a manufactured drug product (outpatient)



Prescription order for a compounded drug product (outpatient)



The components of medication orders are different from outpatient prescriptions and may vary in different institutions. Some items commonly included on completed medication orders (inpatient) are:



1. Patient identification: name, history number, age, weight, height

2. Room number

3. Date and time of order

4. Name, quantity, and dosage form of medications ordered

5. Route of administration

6. Dosage schedule

7. Physician’s signature

8. Name or initials of person(s) who transcribed the order: nurse or pharmacist

9. Date of transcription

Typical inpatient medication order


St. Joseph Hospital


123 Hospital Ln.


90000 Citytown, US













































1Patient David R. Johnson
1Age/Ht/Wt 63/ 5′4″/155 lb
1History number 123456
2Room number 1340
Attending Physician Kim J. Twain, MD
Date Time Orders
301/01/03 31000 45,000 units Heparin Sodium in 100 mL NS


Infuse 5IV over 4 hr6 pre-op

31600 4Cefazolin 5IM Inj. Give 100 mg stat6


Then 50 mg q 6 hr6


7K. J. Twain, MD


8D. Green, RN    01/01/039
301/02/03 31400 4Metoclopramide 10 mg 5IVB over 62 min. and Morphine sulfate 0.5 mg/mL in 100 mL D5W. IV5 infusion through PCA. 6Stat post-op.


7J. D. Peterson (resident MD)


8J Osborn, RPh   01/02/039



7. In a typical prescription, the Inscription defines _________________________ the Subscription shows _________________________ and the Signa displays _________________________.






Solutions. Inscription defines the drug product prescribed.
Subscription shows the dispensing instructions to the pharmacist.
Signa displays the directions for use by the patient.



8. In the following prescriptions for outpatients, identify the basic parts of minimal recommended legal requirements that are missing or are incomplete.



Solutions.



(a) In superscription: symbol is missing; no prescription date; in inscription: metric unit for drug strength and type of dosage form are missing; subscription is missing; signa: no instructions on how to handle refills; prescriber DEA number is missing.

(b) Prescriber complete address; patient complete address; no prescription date; in inscription: complete drug strength per unit of volume and type of dosage form; signa is missing; no instructions on how to handle substitutions.

ABBREVIATIONS



9. As you have seen in the examples provided above, certain abbreviations are routinely used by the prescriber in writing prescriptions. Despite the fact that abbreviations are a convenience, a time saver, a space saver and a way to avoid misspelled words, one should remember that occasionally a price has to be paid for their use. Sometimes, abbreviations are misunderstood, misread, or misinterpreted, leading to a delay in patient care or even harm. Professionals in the health fields should never “create” abbreviations. There are many lists of abbreviations in common use by healthcare workers. Frequently, each health care establishment has its own standardized list, which is used by all personnel. As a rule, where uncertainty exists, the one who wrote the abbreviation must be contacted for clarification.

Abbreviations currently used in writing prescriptions may be related to the type of preparation to be compounded or dispensed (the dosage form), to the directions to the pharmacist, or in the prescription formula. Table 3.2 lists some currently used abbreviations, some of which are derived from the Latin, and their meaning. For a more comprehensive table of abbreviations currently used in the health field, check Appendix 3. Abbreviations may be used sometimes followed by periods or not, and may be written either in upper case or lower case letters.


TABLE 3.2 Some abbreviations currently used by health professionals























































































Abbreviation or term Meaning

Related to dosage forms
cap or caps capsule
chart divided powder; powder in a paper
elix elixir
inj injection
MDI metered dose inhaler
pulv, pulvis powder, bulk powder
sol or soln solution
supp or PR suppository
susp suspension
syr syrup
tab or tabs tablet
ung or unguentum ointment

Used in directions to the pharmacist
disp dispense
DTD, d.t.d. give of such doses
f, ft make
M mix
No., # number of units to be prepared or dispensed
S.A., secundum artem according to art (“use your skill and judgment”)

Related to the prescription formula
or aa of each
aq., aqua water
aq. dest. distilled water
aq. pur. purified water
q.s. a sufficient quantity
q.s. ad a sufficient quantity to make
qs ad a sufficient quantity of each to make

The abbreviation “,” is used when two or more ingredients are present in the same amount. They are listed sequentially with the symbol placed next to the last item of the group to which it refers.


“ qs ad” tells you to add more than one substance to achieve a specified total weight or volume. It is assumed that these substances will contribute equally. In other words, the missing weight or volume is divided equally between the ingredients identified.


Now, try to identify the information that belongs to the superscription, inscription, subscription, signa and special instructions of the following prescription and interpret all abbreviations.





























Benjamin J. Anderson, MD
1678 Hospital Lane, Suite 106, tel. (123) 456-7890
Smithtown, AB
Name: Madeleine J. Stunt Date: 20/03/03
Address: 123 Grand Ave. Smithtown, AB

Lotensin® tabs 20 mg

Disp. 60 tabs

Sig. Tab i a.m. et h.s.

Refills _____02_____ Benjamin Anderson M.D.

Substitution yes DEA No. _____






Solutions. Superscription: symbol
Inscription: Lotensin tablets 20 mg
Subscription: Dispense 60 tablets
Signa: Take one tablet in the morning and at bedtime
Special instructions: 2 refills and substitution permitted.



10. Rewrite the following prescription omitting all abbreviations, so that it makes sense. How much petrolatum should be weighed?















Starch

Talc 5.0 g

Lanolin 10.0 g

Petrolatum qs ad 60.0 g


Solution.



















Starch 5.0 g

Talc 5.0 g (5.0 g “of each” of starch and talc)

Lanolin 10.0 g

Petrolatum 40.0 g (60.0–20.0)

Make an ointment.



11. Prescriptions written in the metric system specify quantities using decimal notation. If units are omitted, and the prescription is written in decimal notation, it is understood that metric units are to be employed: solids are weighed in terms of grams, and liquids are measured in milliliters.


















Zinc oxide

Talc

Starch 5.0

Lanolin

Petrolatum qs ad 60.0

How much petrolatum should be used? (All ingredients are solids)



Solution. 22.5 g


Since the materials are all solids and the quantities are written using decimal notation, they represent weight in grams. 5.0 g of each of zinc oxide, talc and starch makes a total of 15.0 g. The expression “ qs ad” directs that a sufficient quantity of each be used, or, in other words, that the ingredients under the jurisdiction of this abbreviation should be given an equal share in arriving at the final weight. The remaining 45.0 g are shared equally by the lanolin and petrolatum, so we need 22.5 g of each of these.


PRESCRIPTION WRITTEN IN TERMS OF TOTAL QUANTITY DESIRED



12. In compounding dosage forms such as capsules and powders in paper, the pharmacist weighs sufficient of each drug to make all of the required doses. The drugs are combined into a homogeneous mix that is then divided equally among the units being prepared.















Calcium carbonate

Sodium bicarbonate  5.0

Charcoal 0.4

Div in chart No. x

This prescription contains the formula for 10 powders. The pharmacist is directed to weigh the quantities indicated, combine them, and then divide the mass into 10 papers (the abbreviation “div” means divide). The quantity of a drug that will be contained in each powder paper may be calculated by dividing the total weight of the drug by the number of dosage units.


For example, the amount of calcium carbonate in each powder is


equation


Calculate the total weight of material that will be contained in each powder paper.



Solution. 1.04 g


CALCULATIONS


The total weight of powder in the formula is














Calcium carbonate: 5.0 g
Sodium bicarbonate: 5.0 g
Charcoal: 0.4 g
10.4 g

PRESCRIPTION WRITTEN IN TERMS OF A SINGLE DOSAGE UNIT



13. Instead of giving the formula for the desired number of dosage units, the prescription may give the formula for a single unit. To calculate the amount of each drug to be measured, it is necessary to multiply the quantity per unit by the number of units.


This is an old fashioned format, rarely in use these days. The vertical line represents the decimal point. The abbreviation “d.t.d.” means “give such doses” and indicates the number of units that are to be compounded or dispensed. Whenever “d.t.d.” is used, the formula is written for a single unit and must be enlarged by the pharmacist. Both materials are solids, so that the unit of measurement for both is the gram. Thus the amount of aspirin is 300 mg (0.3 g).


Calculate the quantity of each material that should be used to compound the prescription above.







Solution. Aspirin: 1.80 g
Cocoa butter: 10.2 g

CALCULATIONS


To calculate the total amount of aspirin needed, multiply the content of each unit (suppository) by the number of units:


300 mg × 6 = 1800 mg = 1.80 g
Total wt = 2 g per suppository, of which 300 mg is aspirin. Thus
2.00 g total − 0.30 g aspirin = 1.70 g cocoa butter
1.70 g × 6 = 10.2 g


To check:


Sum of weights: 1.80 g + 10.2 g = 12.0 g


Weight of 6 suppositories: 2 g × 6 = 12 g




14. Calculate the quantity of each drug needed for the prescription that follows. All are solids.
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Jun 24, 2016 | Posted by in PHARMACY | Comments Off on Prescription and Medication Orders

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