MEDICAL UNIVERSITY – PLEVEN
DEPARTMENT OF PHARMACOLOGY
STRUCTURE OF THE MEDICAL PRESCRIPTION.
PRESCRIPTION WRITING
Dr D. Pendicheva, Dr G. Stavreva
I. DEFINITION & DESCRIPTION OF THE PRESCRIPTION
II. COMPONENT PARTS OF THE PRESCRIPTION
1. INSCRIPTIO
2. PRAEPOSITIO
3. PRESCRIPTIO
4. SUBSCRIPTIO
5. SIGNATURA
6. NOMEN MEDICI
7. NOMEN AEGROTI
III. PRESCRIPTION TYPES
IV. SYMBOLS & ABBREVIATIONS USED IN PRESCRIPTION
V. UNITS OF MEASUREMANT USED IN THE PRESCRIPTION
Prescription – importance, parts, prescription types, and prescription forms
Prescription importance – medical, pharmaceutical, financial, and legal.
Prescription Parts: Inscriptio, Praepositio, Praescriptio, Subscriptio, Signatura, Nomen
medici, Nomen aegroti. Magistral and official prescriptions
Types of prescription forms: usually white forms with 6-month validity; forms of the National
Health Insurance Fund for drugs prescribed for 1 month with 15-day validity; forms of the
National Health Insurance Fund for drugs prescribed for 3 months with A, B, and C stubs valid
for 15, 45, and 75 days respectively; green and yellow forms with 7-day validity; white forms with
1 blue strip of the Ministry of Health.
Prescription – abbreviations and units
Prescription abbreviations:
Rp/, āā, q. s., tab., tabul., tabl. (from tablet), amp., fl., flac., caps., supp., sc., scat., pulv., ung.,
D. S., M. f., D. t. d., Inf., Dec., Fol., Hb., Sol., T-ra, M-ra, etc.
Meaning of the designations:
Ad, Ad usum proprium, Pro uso suo, Cito, Citissime, Statim, Verte.
Pharmacopeia
The Pharmacopeia offers a collection of articles (specifications and standards) on drugs
listed in alphabetical order. Each article contains the name of the drug in Latin or English, the
empirical and structural formulae, data about the physicochemical properties, methods for
quantitave and/or qualitative identification, storage conditions, maximum single dose, maximum
daily dose, and the pharmacotherapeutic group. In addition, the pharmacopeia describes the
methods for biological standartization of cardiac glycosides, insulin, and other preparations. In
this country the European Pharmacopeia (VI and VII editions) is in effect.
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A practitioners decision to treat a patient assumes that the patient has been evaluated
and diagnosed. The practitioner can then select from a variety of therapeutic
approaches. Drug therapy is most commonly chosen. In most cases, this requires the
writing of a prescription. The prescription order is the most important therapeutic
transaction between a physician and a patient.
A medical prescription is a written order from a doctor to a chemist that includes
instruction for preparing and dispensing medicines to a certain patient.
The prescription represents a mechanism through which a treatment modality is
provided to the patient. A prescription order may be written and issued by a physician,
dentist, veterinarian, or other properly licensed medical practitioner. The prescription
for each patient is a unique entity, designating a specific medication or
medications for a specific patient at a specific time.
While the prescription can be written on any piece of paper, it usually takes a specific
printed form. That form possesses blank spaces for the necessary information. Such
blanks are often supplied to the physician in the form of a pad containing
approximately 100 blank forms. This is a typical printed form for outpatients. In a
hospital setting, drugs are prescribed on a particular page in the patients hospital
chart. A prescription order follows a definite pattern that facilitates its interpretation.
Table 1 shows the manifest functions of the prescription.
Table 1. Manifest functions of the prescription
1.
2.
3.
4.
5.
6.
LEGAL DOCUMENTATION
RECORD SOURCE
MEANS OF COMMUNICATION
THERAPY MODALITY
MEANS OF MEDICAL CONTROL OF THERAPY
MEANS OF CLINICAL TRIAL
All prescription orders should be correct, unambiguous, without cross-outs and signed
clearly for optimal communication between prescriber, pharmacist, and nurse.
It is required that a medical prescription in Bulgaria be written in Latin.
COMPONENT PARTS OF THE PRESCRIPTION
The prescription consists of seven parts. Their Latin names are:
1. INSCRIPTIO
Here written are: the name and the surname of the doctor, the hospital, clinic or
polyclinic medical center, their address, and the date. The date is important from the
standpoint of ascertaining for determining the life of the prescription.
The prescription of narcotics and controlled substances are governed by special laws
and regulations – it cannot be filled after more than 10 days from the date of issuance;
but an order for children – 7 days after the date on which such prescription was issued.
2. PRAEPOSITIO (SUPERSCRIPTION)
consists of the message to the chemist. It includes only the expression Rp./ – an
abbreviation for Recipe, the Latin for Get (Take)
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3. PRESCRIPTIO
is the main part of the medical prescription, because this is the doctor’s order. Here
are the names of medicinal substances, the medicinal forms, and the dosages.
a) brand name (proprietary name) or generic name (INN – international nonproprietary
name) may be used. The medicinal substances are required to begin with a capital
letter and to be in the Genitive case.
The names of all preparations and elements end in -um, Gen sg. –i. The salts end in
Gen. sg. -atis (sulfate); – itis (nitrate); – idi (chloride)
b) the medicinal form can be placed in the beginning of the prescription or after the
drug’s name.
c) the dose is noted after the substance or medicinal form. The strength of the
medication should be written in metric units.
Example: Rp./ Tab. Paracetamoli 0,5 (or 500 mg)
Rp./ Vitamini B12 in ampullis 0,500 mg
4. SUBSCRIPTIO (SUBSCRIPTION)
In this part are written, if necessary, instructions to the chemist on how to make the
preparation and the number of doses, or medicinal forms to be supplied to the patient.
Exampe: Rp./ Tab. Paracetamoli 0,5
Da scatulam № 2 ( D. scat. №2 ) = Give 2 blisters
Rp./ Vitamini B12 0,5 mg
Da tales doses № 10 in ampullis (D. t. d. № 10) = Dispense such doses 20
in number
5. SIGNATURA (MARK, LABEL)
Notes are written in Bulgarian. The signature is the message intended for the patient.
It provides instructions as to how the medicine should be taken by the patient. This
information must be sufficient to allow the patient to understand fully the amount of
the drug product to be taken and the frequency and manner of administration: if the
drug has to be used externally only, or to be shaken well before use, or whether it is a
poison, and other such facts are included.
Example: Signa or Scribe (S.) one tablet three times a day (Ter-in-die, resp.
t.i.d. – three times daily)
Signa or Scribe (S.) One tablet when necessary (Pro re nata – p.r.n.)
6. NOMEN MEDICI
The signature of the doctor may be placed on the designated area, or after the last
drug, and this is for identification data.
7. NOMEN AEGROTI
Name, address and age of the patient. This part serves to identify for whom the
prescription is intended. The full name and the address are required by law on all
prescriptions for controlled substances. The age of the patient is a good additional
piece of information, especially with pediatric pаtients where dosage calculations have
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to be double-checked for safety. This part may be located on the designated area, or
after the last drug on the back of the form.
PRESCRIPTION TYPES
Prescriptions can be classified as compounded and noncompounded.
Compounded prescription, also called formula magistralis (from Latin word
magister – teacher) or extemporaneous prescription is an order that requires mixing of
one or more ingredients (active medicaments) with one or more pharmaceutical
necessities (vehicle, suspending agent). The physician selects the drugs, doses, and
pharmaceutical form that he/she desires and the pharmacist prepares the medication
accordingly. The name of each drug is placed on a separate line right under the
preceding one. The order of ingredients is as follows:
Remedium cardinale (basis). The basis is the principal drug and gives the
prescription its chief action.
Remedium adjuvans (adjuvant). As the name suggests, the adjuvant is a drug that
aids or increases the action of the principal ingredient.
Remedium corrigens (corrective). The corrective modifies or corrects undesirable
effects of the basic or adjuvant.
Remedium constituens (vehicle). The vehicle is the agent used as a solvent in the
solution, to increase the size and volume, or to dilute the mixture. The most potent or
principal drug is written first, the other ingredient second, and the vehicle last, as
shown in the example.
Examples: Rp./ Natrii bromati (bromatis) 6,0
Rem. basis
Phenobarbitali
0,6
Rem. adjuvans
Sirupi Menthae
60,0
Rem. corrigens
Aquae destillatae ad 300,0
Rem. constituens
Misce fiat mixture (Mix to obtain mixture).
Da.Signa. Take 1 tablespoon3 times daily after eating
#
Rp./ Potassium bromate
6,0
Luminal-Sodium
0,6
Syrup of peppermint
60,0
Distilled water up to 300,0
M. D. S. ......
#
Rp./ Anaesthesini (Benzocaini)
Bismuthi subnitrici aa 3.0
Magnesiae ustae
40.0
Misce fiat pulvis (M. f. p.)
D. S. 1/2 teatable during meals.
Noncompounded prescription or fomula officinalis (officina is the Latin word for
workshop) does not require mixing of two or more ingredients to obtain a finished
product. A precompounded order consists of a drug or a mixture of drugs supplied by
a pharmaceutical company by its official or proprietary name and, if it contains more
than one substance, the specific ingredients do not have to be listed.
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SYMBOLS AND ABBREVIATIONS USED IN PRESCRIPTION
aa is the abbreviation of ana partes aequales (in equal quantities), expressing “the
substances are in equal quantities”.
Ad is used to express “add to get the whole weight of the preparation” or “up to”,
when the drugs are solved in a neutral substance.
q.s. – quantum satis means “as much as is it necessary”.
D. t. d. № – “Da tales doses” means “dispense such doses … in number”.
D. scat. № – Da scatulam – “Give … blisters”.
M.D.S. – “Mix, give and note”.
M. f. + the medicinal form in nominative – “Mix to obtain”.
Verte! – when you need to continue writing on the back of the form. This should
be written near the bottom of the prescription form, at the right angle.
Some abbreviations of medical forms are: pulv. (pulvis) – powder; ung. (ungventum)
– ointment, unguent; sol. (solutio) – solution; supp. (suppositorium) – suppository;
tab. (tabletta) – tablet.
UNITS OF MEASUREMENT USED IN THE PRESCRIPTION
The strength of the drugs should be written in metric units.
Quantities of drugs are measured in grams, milligrams, and micrograms.
The gram (g) is the basic unit of weight in the metric system.
One one-thousandth of a gram is 1 milligram (mg). One one-thousandth of a
milligram is 1 microgram (μg) or 1 mcg. One thousand grams is one kilogram (table
2).
The liter is the basic unit of volume in the metric system. We commonly use the
milliliter (ml), which is one one-thousandth of a liter. The unit cubic centimeter, or cc,
is used as an equal to ml. The strength of a solution is usually expressed as the
quantity of a solute in a sufficient solvent to make 100 ml; for instance, 20%
potassium chloride solution is 20 grams of KCl per 100 ml (g/100 ml).
The gram is equal to the weight of 1 ml of distilled water at 4o C (Celsius) in vacuum.
The weight and measures of the metric system are given in Table 2.
Table 2. Weights and measures
MASS
CAPACITY
METRIC SYSTEM
1000 grams (SI: 1000 g)
1.0 gram (SI: 1 g)
0.001 gram (SI: 1 mg)
10-6 gram (SI: 1 microgram!)
10-9 gram (SI: 1 ng)
1000 milliliters (SI: 1000 ml)
100 milliliters (SI: 100 ml)
10 milliliters (SI: 10 ml)
1.0 cubic centimeter (SI: 1 ml)
0.001 milliliter
1 kilogram (kg)
(g)
milligram (mg)
microgram (μg or mcg)
nanogram (ng)
liter (l)
deciliter (dl)
centiliter (cl)
milliliter (ml, cc)
microliter (μl or mcl)
cubic millimeter (cmm)
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PHARMACOPEIAS AND FORMULARIES
The book of standards for drugs and devices, known as pharmacopeia and formularies,
are collectively referred to as drug compendia.
A pharmacopeia or a formulary is a book containing a list of medicinal substances
(drugs) and articles (devices) with description, tests, and formulas for their
preparation, selected by a recognized authority. The recognized authority which issues
these standards in most countries is govermental.
Official drug compendia have been recognized as standards of purity, quality, and
strength by a governmental agency of the country.
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