awesome knowledge provide about drug dosages pharma

1. INTRODUCTION TO
PHARMACOLOGY

2. PHARMACOLOGY
Is science that studies interactions of drugs with organism
on different levels (subcellular, cellular, organ, systemic)
Is the branch of medicine and biology concerned with the study
of drug action, where a drug can be broadly defined as any man-
made, natural, or endogenous (from within body) molecule which
exerts a biochemical and/or physiological effect on the cell, tissue,
organ, or organism
Is the body of knowledge concerned with the action of chemicals
on biologic systems

3. PHARMACOLOGY STUDIES
• relationship between chemical structure and biologic
activity
• site of effect localisation
• mechanism of action
• fate of drug in organism
• evaluation of relationship between
dose and biologic effect

4. WHAT SHOULD YOU KNOW
ABOUT THE DRUG?
Non-proprietary (generic) drug name (not necessary to know
proprietary (trade name))
The class to which the drug belongs
Mechanism of action
Indications, contraindications
Adverse drug reactions, interactions
Pharmacokinetic parameters (especially the ones
characteristic for the drug)
Non-pharmacological treatments that are effective
alternatives or complementary to pharmacotherapy

5. SOURCES OF INFORMATION
IN PHARMACOLOGY

6. PRIMARY LITERATURE
Pharmacopoeia: It is a book that contains a list of
established and officially approved drugs having
description of their physical and chemical characteristics
with tests for their identification, purity, methods of
storage, etc.
Some of the pharmacopoeias are
the British Pharmacopoeia (BP),
the European Pharmacopoeia and
the United States Pharmacopoeia (USP).

7. SECONDARY LITERATURE
Other sources of drug information are National Formulary
(NF), Martindale—the Extra Pharmacopoeia, Physician’s Desk
Reference (PDR), American Medical Association Drug
Evaluation, textbooks and journals of Pharmacology and
therapeutics, drug bulletins, databases like drug Micromedex,
Medline, Cochrane Library, etc.
Formulary: It provides information about available drugs
— their use, dosage, adverse effects, contraindications,
precautions, warnings and guidance on selecting right
drug for a range of conditions.

8. TERTIARY LITERATURE
Click on the textbook cover
to download
The main
textbook

9. HISTORY OF
PHARMACOLOGY

10. PHARMACOLOGY IN THE ANCIENT
WORLD
Hippocrates of Kos (c. 460 – c.
370 BC) was a Greek physician,
and is considered one of the most
outstanding figures in the history of
medicine.
He is referred to as the "Father of
Western Medicine“ in recognition of
his lasting contributions to the field
as the founder of the Hippocratic
School of Medicine.

11. The therapeutic approach was based on "the healing
power of nature". According to this doctrine, the body
contains within itself the power to re-balance the four
humours and heal itself.
Hippocratic therapy focused on simply easing this
natural process. In general,
the Hippocratic medicine was very
kind to the patient; treatment was
gentle, and emphasized keeping
the patient clean and sterile.

12. Aelius Galenus or Claudius
Galenus (AD 129 - c. 200/c. 216), better
known as Galen of Pergamon, was a
prominent Greek physician, surgeon and
philosopher in the Roman empire.
He found the basics of pharmacology.
Galenicals are still widely used and known as
tinctures and ointments prepared in a certain
way.
He claimed that there are active and
ballast substances in drugs of plant and
animal origin, and treated by using plant
extracts, wines, syrups, vinegar and honey
mixtures.

13. Mural painting showing Galen and Hippocrates
12th century; Anagni, Italy

14. PHARMACOLOGY IN THE
RENAISSANCE
Paracelsus (born Philippus Aureolus
Theophrastus Bombastus von
Hohenheim, 1493 – 1541) was a Swiss
German Renaissance physician, botanist,
alchemist, astrologer, and general occultist.
He founded the discipline of toxicology.
Paracelsus wrote: “Dosis facit venenum
(Die Dosis macht das Gift; The dose makes
the poison). That is to say, substances
considered toxic are harmless in small
doses, and conversely an ordinarily
harmless substance can be deadly if over-
consumed.

15. Paracelsus’ works

16. PHARMACOLOGY IN THE ISLAMIC
WORLD
Avicenna (Ibn-Sīnā, full name Abū ʿAlī al-
Ḥusayn ibn ʿAbd Allāh ibn Al-Hasan ibn Ali
ibn Sīnā; c. 980 – June 1037) was a Persian
polymath and jurist who is regarded as one of
the most significant thinkers and writers of
the Islamic Golden Age.
One of his most famous works is The Canon
of Medicine – a medical encyclopedia.
The book is known for its description
of contagious diseases and sexually
transmitted diseases, quarantine to limit the
spread of infectious diseases, and testing of
medicines.

17. A Latin copy of The Canon of Medicine, dated 1484, located at the P. I. Nixon Medical
Historical Library, University of Texas Health Science Center at San Antonio.

18. The canon medicine testing
• The drug must be free from any extraneous accidental quality.
• It must be used on a simple, not a composite, disease.
• The drug must be tested with two contrary types of diseases, because
sometimes a drug cures one disease by Its essential qualities and another
by its accidental ones.
• The quality of the drug must correspond to the strength of the disease.
For example, there are some drugs whose heat is less than the coldness
of certain diseases, so that they would have no effect on them.
• The time of action must be observed, so that essence and accident are
not confused.
• The effect of the drug must be seen to occur constantly or in many
cases, for if this did not happen, it was an accidental effect.
• The experimentation must be done with the human body, for testing a
drug on a lion or a horse might not prove anything about its effect on man

19. GREAT SCIENTISTS AND THEIR
CONTRIBUTION
Paul Ehrlich (1854 – 1915) was a German
physician and scientist who worked in the
fields of hematology, immunology, and
antimicrobial chemotherapy.
He invented the precursor technique
to Gram staining bacteria. His laboratory
discovered arsphenamine (Salvarsan), the
first effective medicinal treatment for syphilis,
thereby initiating and also naming the concept
of chemotherapy. Ehrlich popularized the
concept of a "magic bullet.”

20. Sir Alexander Fleming (1881 – 1955) was
a Scottish biologist, pharmacologist and
botanist. He wrote many articles on
bacteriology, immunology, and chemotherapy.
His best-known discoveries are the enzyme
lysozyme in 1923 and the antibiotic substance
benzylpenicillin (Penicillin G) from the mould
Penicillium notatum.
"When I woke up just after dawn on
September 28, 1928, I certainly didn't plan to
revolutionise all medicine by discovering the
world's first antibiotic, or bacteria killer,"
Fleming said, "But I suppose that was exactly
what I did."

21. Edward Calvin Kendall (1886 – 1972)
was an American chemist.
With Swiss chemist Tadeus Reichstein
and Mayo Clinic physician Philip S. Hench,
he discovered and investigated the
hormones of the adrenal gland.
Kendall did not only focus on the adrenal
glands, he was also responsible for the
isolation of thyroxine, a hormone of
the thyroid gland and worked with the team
that crystallized glutathione and identified its
chemical structure.

22. Alfred Goodman Gilman (born July 1,
1941) is an American pharmacologist and
biochemist.
It was Gilman who actually discovered
the proteins that interacted with the GTP to
initiate signaling cascades within the cell.
Earlier Rodbell had shown in the 1960s
that GTP was involved in cell signaling.
He was Nobel laureates in Pharmacology
in 1994 for Discovery of G proteins and
the role of these proteins in signal
transduction in cells

23. DRUG DOSAGE FORMS
and how to prescribe them

24. DRUG NOMENCLATURE

25. DRUG NOMENCLATURE
A drug generally has three categories of names:
1. Chemical name: It denotes the chemical structure of the drug, e.g.
acetylsalicylic acid is the chemical name of aspirin and N-acetyl-p-
aminophenol for paracetamol. It is not suitable for use in a prescription.
2. Non-proprietary name: It is assigned by a competent scientifi c
body/authority, e.g. the United States Adopted Name (USAN) council. It is
commonly used as generic name. It should be used ideally in prescriptions
because it is economical and uniform all over the world than the branded
counterparts, e.g. aspirin and paracetamol are generic names.
3. Proprietary name (brand name): It is given by the drug
manufacturers. Brand names are short and easy to recall. A drug usually
has many brand names—it may have different names within a country and
in different countries. Brand names can also be used in prescriptions, e.g.
Disprin is a brand name of aspirin; Crocin is a brand name of paracetamol.

26. Chemical name Non-proprietary name Proprietary/brand name
Acetylsalicylic acid Aspirin Disprin, Ecosprin
N-acetyl-p-aminophenol Paracetamol Crocin, Metacin, Tylenol
Many older drugs still have more than one non-proprietary names,
e.g. «meperidine» and «pethidine» or «lidocaine» and «lignocaine»
for the same drugs.
Until the drug is included in a pharmacopoeia, the non-proprietary
name may also be called the approved name. After its appearance
in the official publication, it becomes the official name.

27. LEGAL CATEGORIES OF DRUGS
Drugs may be categorized according to legal restrictions governing their
use as over-the-counter (OTC), prescription (synonyms: legend,
dangerous, Rx only), or controlled drugs.
As determined by the U.S. Food and Drug Administration FDA), a
prescription drug (now designated “Rx only”) is one that requires a
prescription to be dispensed by a pharmacist, whereas an OTC drug
can be purchased without a prescription (pharmacy medicines (P),
which may be sold by a pharmacist without prescription, general sales list
(GSL) medicines that may be sold without a prescription in any shop).
Drugs with an abuse potential, called controlled substances, have
additional restrictions placed on their use

28. Over-the-counter drugs (OTC drugs) - OTC or nonprescription
drugs are the drugs that can be sold to a patient without the need for
a doctor’s prescription, e.g. paracetamol, antacids, etc.
Prescription drugs - These are the drugs that can be obtained
only upon producing a prescription by a registered medical
practitioner, e.g. antibiotics, antipsychotics, etc.
Orphan drugs - Drugs that are used for the diagnosis, treatment
or prevention of rare diseases. The expenses incurred during the
development, manufacture and marketing of drug cannot be
recovered from selling the drugs by the pharmaceutical company,
e.g. digoxin antibody (for digoxin toxicity), fomepizole (for methyl
alcohol poisoning), etc.

29. CLASSIFICATION OF CONTROLLED
SUBSTANCES
Schedule =
Class
Criteria for Inclusion Examples of Drugs
I
High abuse potential, no currently
accepted medical use, may lead
to severe dependence
Research use only: heroin, lysergic
acid diethylamide, marijuana*,
mescaline, methaqualone, peyote,
psilocybin
II
High abuse potential,
accepted medical use, may
lead to severe dependence
Amphetamines, cocaine,
codeine, dronabinol, meperidine,
methadone, methylphenidate,
morphine, oxycodone,
pentobarbital, secobarbital
all hydrocodone products

30. CLASSIFICATION OF CONTROLLED
SUBSTANCES
Schedule Criteria for Inclusion Examples of Drugs
III
Abuse potential less than drugs
in Schedules I or II, accepted
medical use, moderate to low
physical dependence liability,
possibly high psychological
dependence
Benzphetamine, butabarbital,
methyprylon, mixtures of
codeine with aspirin or
acetaminophen, stanozolol
IV
Abuse potential less than drugs in
Schedule III, accepted medical use,
low dependence liability
Chloral hydrate, diazepam,
meprobamate, phenobarbital,
propoxyphene, triazolam
V
Abuse potential less than drugs in
Schedule IV, accepted medical use,
limited dependence liability
Cough preparations containing
codeine or similar opioid derivatives,
pseudoephedrine-containing
decongestants

31. DRUG DOSAGE FORMS

32. DOSAGE FORM
A term for the physical characteristics of a drug product
– e.g., tablet, capsule or solution – which contains the
drug substance and almost invariable other ingredients,
such as excipient, fillers, flavours, preservatives,
emulsifiers, etc.
Segen’s Medical Dictionary © 2012 Farlex, Inc

33. REASONS FOR THE NEED OF DOSAGE FORMS
 to protect the drug substance from destructive influences of
atmospheric oxygen
 to protect the drug from the destructive influence of gastric
acid after oral administration
 to conceal the bitter, salty, or offensive taste or odor of a
drug substance
 to provide for insertion of a drug into one of the body’s
orifices
 to provide optimal drug action from topical administration
sites, etc.

34. DOSAGE FORMS ARE CLASSIFIED
ACCORDING TO:
PHYSICAL
FORM
solid
semisolid
liquid
gaseous
ROUTE OF
ADMINISTRATION
for systemic
administration
for local
administration

35. Solid
Tablets
Powder
Capsules
Granules
Species
Semisolid
Ointment
Cream
Suppositories
Patch/Plaster
Paste
Liquid
Solution
Syrup
Tincture
Suspension
Emulsion
Gaseous
Aerosol
Spray

36. SOLID DOSAGE FORMS
TABLET: It is the commonly used solid dosage form. A tablet
may be scored and can be easily broken along the line, if required,
e.g. paracetamol. Tablets can be uncoated or coated (covered with a
thin fi lm of another substance) to improve the taste, delay
absorption, revent its degradation in the stomach, etc. Sugar coating
of a tablet helps to improve its taste, e.g. metronidazole.

37. Enteric-coated tablet: It is coated with a material that delays the
release of medication till it reaches the intestine. Enteric coating of a
drug prevents the destruction of the drug by gastric acid, e.g.
enteric-coated tablet of erythromycin, or decreases the gastric
irritation by the drug, e.g. entericcoated tablet of diclofenac.
Sustained-release preparations: They help to prolong the
duration of action of a drug, thereby decreasing the frequency of
drug administration and improving patient compliance, e.g.
sustainedrelease tablet of diclofenac (for pain).
Chewable tablet: It should be chewed and swallowed. This helps
to increase the effectiveness of the drug, e.g. chewable antacid
tablet used for gastritis and chewable albendazole tablet for worm
infestation.
Dispersible tablet: It is a tablet that has to be dispersed in water
or milk before administration, e.g. aspirin dispersible tablet.

38. SOLID DOSAGE FORMS
CAPSULE: It is a solid dosage form where the drug is enclosed
within a soluble sheath. Capsules can be oval, cylindrical or
spherical, e.g. amoxicillin.
Sustained-release and enteric-coated capsules are also available.
Spansules and timsules are sustained release forms. Time-release
forms may have the suffix like SR (sustained release), CR
(controlled release), ER (extended release), SA (sustained action),
contin (continuous), retard, etc.s.

39. SOLID DOSAGE FORMS
LOZENGE: It is a solid dosage form placed in the mouth and
sucked; it dissolves slowly to liberate the active ingredient. It soothes
the irritated mucosa of the throat. Some lozenges have systemic
effect, e.g. nicotine lozenges to reduce withdrawal symptoms and
craving associated with cessation of smoking; dyclonine (local
anaesthetic) lozenge for sore throat.

40. SOLID DOSAGE FORMS
BULK (UNDIVIDED) POWDERS are multidose
preparations consisting of solid, loose, dry particles of varying
degrees of fineness.
The powder is then usually dispersed in water or, in the case
of effervescent powders, dissolved before taking.
DIVIDED POWDERS are single-dose presentations of
powder ( for example, a small sachet) that are intended to be
issued to the patient as such, to be taken in or with water.

41. SOLID DOSAGE FORMS
SUPPOSITORY: It is a small solid medicated mass, usually
cone-shaped ,that is inserted either into the rectum (rectal
suppository), vagina (vaginal suppository or pessaries) where
it melts at body temperature .

42. SEMISOLID DOSAGE FORMS
OINTMENT: It is a semisolid preparation with a greasy
base usually meant for application to skin or mucosa, e.g.
lignocaine ointment for local anaesthesia, acyclovir
ointment for herpetic infections.

43. SEMISOLID DOSAGE FORMS
CREAM: It is a semisolid emulsion for local application, e.g.
antifungal agent (nystatin cream) for oropharyngeal
candidiasis; antiviral agents (acyclovir and penciclovir cream)
for herpetic labialis; glucocorticoid (betamethasone and
clobetasol) intraoral cream for severe aphthous stomatitis.
PASTE: It is a semisolid preparation with a less-greasy base
generally meant for topical use, e.g. triamcinolone acetonide
paste for oral inflammatory conditions. Pastes are stiffer and
easily washable than ointments.

44. SEMISOLID DOSAGE FORMS
GEL: It is a jelly-like substance formed by the aqueous
suspension of insoluble drugs, e.g. diclofenac gel for pain,
lignocaine gel as a local anaesthetic, povidone iodine gel for
sore throat, glucocorticoid (betamethasone and clobetasol) gel
for severe aphthous stomatitis.
TRANSDERMAL PATCH, or SKIN PATCH: It is a medicated
adhesive patch that is placed on the skin to deliver a specific
dose of medication through the skin and into the bloodstream.

45. LIQUID DOSAGE FORMS
MIXTURE: It is a liquid containing two or more ingredients
for oral use. For example, sodium salicylate mixture as an
analgesic and antipyretic; gripe water mixture used in infant to
reduce gripping; carminative mixture to expel gas from the
stomach and the intestine.
EMULSION: It is a mixture of two immiscible liquids (e.g. oil
and water) made miscible by using an emulsifying agent, e.g.
cod-liver-oil emulsion for vitamin D deficiency.
SUSPENSION: It contains one or more insoluble ingredients
suspended in a liquid, e.g. antacid suspension, amoxicillin
suspension, etc. It should be shaken well before use.

46. LIQUID DOSAGE FORMS
SYRUP: It is a concentrated solution of sugar containing the
drug to mask the bitter taste of the drug, e.g. cough syrup.
ELIXIR: It is a clear, pleasantly fl avoured liquid dosage form
that contains a drug dissolved in water and alcohol, e.g.
promethazine elixir for suppressing dry cough.
LINCTUS: It is a viscous liquid preparation that should be
sipped slowly to allow it to trickle down the throat. It is usually
used for relief of cough, e.g. linctus codeine.
GARGLE: An aqueous solution used to prevent or treat
throat infections, e.g. saline gargle for sore throat.

47. LIQUID DOSAGE FORMS
MOUTH RINSES: An aqueous solution used for rinsing the
mouth for oral hygiene, e.g.:
• antiseptic mouth rinse (chlorhexidine or povidone iodine)
used in gingivitis.
• astringent mouth rinse (tannic acid) is used for gingivitis and
aphthous ulcers.
• anticaries mouth rinse (sodium fl uoride) to prevent dental
caries.
TINCTURE: It is an alcoholic preparation of a drug, e.g.
tincture of iodine used as an antiseptic.

48. LIQUID DOSAGE FORMS
IRRIGATION SOLUTIONS: They are used for washing out a
body cavity or wound and the procedure is known as irrigation.
Water, saline and antiseptic solutions can be used as irrigants.
Oral irrigation can be done for preventing and treating
inflammatory conditions of the oral cavity.
DROPS: They are liquid preparations meant for oral (vitamin
drops, paracetamol drops) or local (eye, ear and nose)
administration.
SPRAY: It discharges the drug in droplet form for topical
application, e.g. lignocaine spray for local anaesthesia,
nitroglycerine lingual spray for angina attack.

49. LIQUID DOSAGE FORMS
IRRIGATION SOLUTIONS: They are used for washing out a
body cavity or wound and the procedure is known as irrigation.
Water, saline and antiseptic solutions can be used as irrigants.
Oral irrigation can be done for preventing and treating
inflammatory conditions of the oral cavity.
DROPS: They are liquid preparations meant for oral (vitamin
drops, paracetamol drops) or local (eye, ear and nose)
administration.
SPRAY: It discharges the drug in droplet form for topical
application, e.g. lignocaine spray for local anaesthesia,
nitroglycerine lingual spray for angina attack.

50. GASEOUS DOSAGE FORMS
AEROSOL: It is a product that is packaged under pressure
and contains therapeutically active ingredients that are
released upon activation of an appropriate valve system; it is
intended for topical application to the skin as well as local
application into the nose (nasal aerosols), mouth (lingual
aerosols), or lungs (inhalation aerosols).

51. BASIC PRINCIPLES OF DRUG
PRESCRIPTION

52. PRESCRIPTION
A prescription is a written, verbal, or electronic order
for medication to be used for the diagnosis, prevention, or
treatment of a specific patient’s disease by a licensed
physician, dentist, podiatrist, or veterinarian.
A prescription is a legal document for which the
prescriber and the pharmacist are responsible.
Prescriptions are subject to state, federal, and local
regulations, with multiple stakeholders at each level.

53. PRESCRIPTION’S STRUCTURE
Superscription
Inscription
Subscription
Signature

54. SUPERSCRIPTION
The symbol Rx, known as the
superscription, is generally understood
to be an abbreviation of the Latin recipe,
meaning “take thou,” but it was probably
derived from the ancient Roman symbol
for Jupiter and used in the physician’s
prayer for the survival of the patient.

55. INSCRIPTION
The inscription provides specific information about the drug
preparation:
 the name of the drug, which can be either the non-
proprietaryor the proprietary name, or possibly both, with the
proprietary name following the nonproprietary name in
parentheses, as with pentazocine (Talwin)
 the unit dosage or amount of the drug in milligrams (e.g.,
penicillin VK 500 mg) or other appropriate unit of measure
(e.g., penicillin G 250,000 U) and the dosage form (e.g.,
tablets, suspension, sprinkles)

56. If the prescription is for a liquid preparation, the
individual unit of dosage is usually contained in a
teaspoonful or 5 mL (e.g., amoxicillin 125 mg/5 mL). The
inscription should provide an unambiguous identification
of the drug and any other ingredients that the pharmacist
must assemble to fill the prescription order.
Drug products are available in unique strengths and
dosage forms. When prescribing, a product, strength, and
dosage form that is available to the pharmacist should be
designated. The inscription should be written just below
and to the right of the superscription.

57. SUBSCRIPTION
The subscription is the prescriber’s directions to the
pharmacist regarding fulfilling the inscription. Because almost
all drugs used by dentists are available in manufactured
dosage forms, the subscription is usually brief, including the
following:
1. The quantity (and dosage form) of the drug to be
dispensed; that is, the number of tablets or capsules or the
volume of a liquid preparation needed for a course of therapy
(e.g., “dispense 28 tablets”).

58. This direction is written, preferably in Arabic numerals, for an appropriate amount of the
drug to supply the patient for the full course of the intended therapy. The prescriber also
considers the toxicity and abuse potential of the drug and the cost to the patient. For DEA-
controlled drugs (Drug Enforcement Agency) , the quantity must be written in numbers and
spelled out (in English, not Latin) to avoid alteration. (Without this precaution, 15 is easily
changed to 45, 75, or 150.)
Alternatively, the prescription may have a check-off box for the range of doses that includes
the amount to be dispensed. In any prescription, no greater quantity of drug than is needed
should be ordered. In the case of electronic prescriptions, sent directly to the pharmacy, only
the numerical designation of the quantity is required as the patient does not handle the
prescription. In some cases, the amount prescribed should be limited to prevent obscuring
symptoms, such as prescribing analgesics for 3 or 4 days rather than the 7 to 10 days as is
common for antibiotics.
If multiple appointments are anticipated, it may be more cost-effective to write the amount
to reflect several appointments. The subscription should be on the line below the last line of
the inscription. Directions to the pharmacist to list the name of the medication will be on the
container label and this is indicated by writing “label.”

59. SUBSCRIPTION
2. Instruction to the pharmacist if the prescription can be
refilled without the prescriber writing a new prescription.
The number and its time limitation are specified for DEA-controlled drugs, but they are
otherwise left to the discretion of the practitioner. Some state laws dictate, however, that
prescriptions expire at the end of each year. If refill directions are not authorized by the
prescriber, no refills may be dispensed. With controlled substances, care should be
taken to devise a refill authorization system that is not easily altered, such as crossing
out all except the desired number in a series (e.g., 0, 1, 2, etc.). The refill instructions are
usually physically located below the transcription.

60. SUBSCRIPTION
3. Dispensing characteristics of the drug.
To save patients money, some states allow dispensing up to three refills (for a 90-day
supply of drug) at the same time unless the practitioner notes that the “refill schedule is
medically necessary” on the prescription. This exception is not made for controlled
substances or psychotropics. In the case of fluoride prescriptions, it would be wise to specify
“refill schedule is medically necessary.”

61. SIGNATURE
The transcription, or signature – from the Latin signa, meaning
“label” or “let it be labeled” and indicated on the prescription by
“Label:” or “Sig:”—is the prescriber’s directions to the patient that
appear on the medicine container.
At one time, such directions were uniformly written in Latin, but
modern practice is to use English. Latin abbreviations are still used
by many clinicians in prescriptions and progress notes to save time;
however, such gains are minor in general dental practice and may
contribute to prescription errors (e.g., “q4h” instead of “qid”
represents a 50% dosage increase).
The use of Latin in writing prescriptions is outmoded and can be
confusing. Its use in prescriptions is highly discouraged.

62. SIGNATURE

63. SOME LATIN ABBREVIATIONS
USED IN PRESCRIPTION WRITING
ABBREVIATION LATIN ENGLISH
ad lib. ad libitum at pleasure
a.c. ante cibum before meals
aq. aqua Water
b.i.d. bis in die twice a day
caps. capsula Capsule
disp. dispensa Dispense
gtt. guttae Drops
h. hora Hour
h.s. hora somni at bedtime
non rep. non repetatur do not repeat (or refill)

64. SOME LATIN ABBREVIATIONS
USED IN PRESCRIPTION WRITING
ABBREVIATION LATIN ENGLISH
p.c. post cibum after meals
p.r.n. pro re nata as needed
q.h. quaque hora every hour
q.4h. quaque quarta hora every 4 hours
q.i.d. quater in die four times a day
Sig. signa let it be labeled, label
stat. statim immediately
tab. tabella Tablet
t.i.d. ter in die three times a day

65. The phrase “use as directed” should not be used. Rather, the transcription should be
explicit and include
 the route and method (e.g., take, instill, or insert);
 the number of dose forms to be taken each time (e.g., take two tablets);
 how frequently to administer the medication (e.g., every 6 hours or at bedtime);
 for what length of therapy (e.g., for 7 days or until all taken);
for what purpose (now required by law in some states; e.g., for an analgesic, “to relieve
pain” or “for pain”);
 any special instructions (e.g., shake well before using or refrigerate).
The instructions to the patient should be consistent with the patient characteristics, drug,
and dosage form. Prescriptions written for children should use the verb give instead of take to
indicate that the parent or guardian is to administer the drug. Enteric-coated drugs should be
“swallowed whole” to ensure that the coating is still intact when the drug reaches the stomach.
Directions for suspensions should include the phrase “shake well then take …” to ensure
administration of a uniform dose. The transcription should be located on the next line after the
subscription.

66. DRUG LABEL FOR TAGAMET
Courtesy of
Glaxo-SmithKline

67. PRESCRIPTION WRITING
Doctor's Name
Address
Phone Number
Patient's Name/Date
Patient's Address/Age
Rx
Drug Name/Dosage Size
Disp: Number of tablets, capsules, ounces to be dispensed (roman numerals added as
precaution for abused drugs)
Sig: Direction on how drug is to be taken
Doctor's signature
State license number
Drug Enforcement Agency (DEA) number (if required)

68. TYPICAL PRESCRIPTION FORM

69. SINGLE-ENTITY VS COMBINATION
PRESCRIPTIONS
A single-entity prescription is one written with only one active
ingredient, the agent that produces the desired effect (e.g.,
ibuprofen 600-mg tablets), in contrast to a combination
prescription, which calls for a preparation with more than one
active ingredient (e.g., aspirin, 230 mg; acetaminophen, 150
mg; caffeine, 30 mg; and hydrocodone bitartrate, 5 mg).
Many combination formulations are available pre-
compounded, in a single fixed-dosage form, and they may be
prescribed in the same manner as a single drug (e.g., codeine
and acetaminophen tablets or Tylenol with codeine).

70. SAMPLE PRESCRIPTIONS
The prescription, for a
combination product,
is written by trade name
for convenience (generic
substitution is permitted).
The prescription is written
by nonproprietary name

71. SAMPLE PRESCRIPTIONS
Rx:
Acetaminophen 325 mg tablets
Disp: To be determined by practitioner
Sig: Take 2 tablets every 4 hours
Note: Products include Tylenol and others
Rx:
Ibuprofen 400 mg tablets
Disp: 20 tablets
Sig: Take 1 tablet every 4 to 6 hours as
needed for pain
Note: Prescription strength ibuprofen is
available as the brand name Motrin.
Rx:
Norco 10 mg
Disp: 16 tablets
Sig: Take 1 or 2 tablets every 4 hours as
needed for pain; not to exceed 8 tablets
in 24 hours
Note: Restrictions: C-II; no refills
Ingredients: Hydrocodone 10 mg and
acetaminophen 325 mg; available as generic equivalent
Rx:
Amoxicillin 250 mg
Disp: 30 capsules
Sig: Take 1 capsule 3 times/day for 7 to
10 days

72. SAMPLE PRESCRIPTIONS
Rx:
Chlorhexidine gluconate 0.12% oral rinse
Disp: 32 oz bottle
Sig: Rinse vigorously twice daily with 15 to
20 mL for 30 seconds and expectorate
Note: It is also available in an alcohol-free
formulation in most pharmaceutical locations.
Advise patient of risk of reversible tooth staining
Rx:
Sporanox oral solution 10 mg/mL
Disp: 300 mL
Sig: Take 200 mg (4 teaspoonfuls) once
daily for 14 days
Ingredient: Itraconazole
Rx:
Listerine antiseptic mouthwash [OTC]
Disp: Various size bottles
Sig: Rinse vigorously twice daily with 15
to 20 mL for 30 seconds and expectorate
Note: Various formulations are also available in
an alcohol-free formulation.
Rx:
Nystatin (Oral) 100,000 units/mL oral
suspension
Disp: 300 mL
Sig: Rinse with 1 teaspoon (5 mL) for 2
minutes 4 to 5 times/day and expectorate

73. SAMPLE PRESCRIPTIONS
Rx:
Nystatin (Topical) ointment
Disp: 15 g tube
Sig: Apply locally as directed with a thin
coat to inner surface of denture and the
affected area 4 to 5 times/day
Rx:
Zovirax cream 5%
Disp: 5 g tube
Sig: Apply thin layer to lesions 5 times/day
for the duration of the external lesions
Ingredient: Acyclovir (Topical)
Rx:
Mycelex 10 mg troches
Disp: 70 troches
Sig: Dissolve 1 troche in mouth 4 to 5
times/day until gone; leave any
prosthesis out during treatment and
soak prosthesis in nystatin liquid
suspension overnight
Ingredient: Clotrimazole (Oral)
Rx:
Fluocinonide 0.05% gel
Disp: 45 g tube
Sig: Apply locally as directed to lesion 4
times/day

74. SAMPLE PRESCRIPTIONS
Rx:
Decadron 0.5 mg per 5 mL elixir
Disp: 500 mL bottle
Sig: For 3 days, rinse with 1 tablespoonful
(15 mL) 4 times/day and swallow; then for
3 days, rinse with 1 teaspoonful (5 mL) 4
times/day and swallow; then for 3 days,
rinse with 1 teaspoonful (5 mL) 4
times/day and swallow every other time.
Then for 3 days rinse with 1 teaspoonful
(5 mL) 4 times/day and expectorate.
Continue the rinse and expectorate mode
for 2 minutes but discontinue medication
when mouth becomes completely
comfortable.
Rx:
Afrin nasal spray [OTC]
Disp: 15 mg
Sig: Spray once in each nostril every 6
to 8 hours for no more than 3 days
Ingredient: Oxymetazoline (Nasal)
Ingredient: Dexamethasone (Systemic); the
practitioner can tailor this rinse, hold expectorate
and/or swallow prescription to the severity and
lesion location for each individual patient.

75. PREVENTING PRESCRIBING ERRORS
 Ensure correct patient by using at least 2 patient identifiers on the
prescription (eg, full name, birth date, or address). Review
prescription with the patient or patient's caregiver.
 Always use a leading zero for numbers <1 (0.5 mg is correct and
.5 mg is incorrect) and never use a trailing zero for whole numbers
(2 mg is correct and 2.0 mg is incorrect).
 Always use a space between a number and its units as it is easier
to read. There should be no periods after the abbreviations mg or
mL (10 mg is correct and 10mg is incorrect).
 For doses that are ≥1,000 dosing units, use properly placed
commas to prevent 10-fold errors (100,000 units is correct and
100000 units is incorrect).

76. PREVENTING PRESCRIBING ERRORS
 Do not prescribe drug dosage by the type of container in which the
drug is available (eg, do not prescribe "1 amp", "2 vials", etc).
 Do not write vague or ambiguous orders which have the potential
for misinterpretation by other health care providers. Examples of
vague orders to avoid: "Resume pre-op medications," "give drug per
protocol," or "continue home medications."
 Review each prescription with patient (or patient's caregiver)
including the medication name, indication, and directions for use.
 Take extra precautions when prescribing high alert drugs (drugs
that can cause significant patient harm when prescribed in error).
Common examples of these drugs include: Anticoagulants,
chemotherapy, insulins, opioids, and sedatives.

77. THANK YOU FOR YOUR
ATTENTION!
Pages
1-8, 495-503
Pages
14-21, 28-33
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