PDF Mosbys Pharmacy Review for the NAPLEX , 1e 1 Csm Pap Edition PDF Download

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®

ISBN: 978-0-323-04910-8

Mosby’s Pharmacy Review for the NAPLEX

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Notices
Knowledge and best practice in this field are constantly changing. As new research and
experience broaden our understanding, changes in research methods, professional practices,
or medical treatment may become necessary.
Practitioners and researchers must always rely on their own experience and knowledge in
evaluating and using any information, methods, compounds, or experiments described herein.
In using such information or methods they should be mindful of their own safety and the safety
of others, including parties for whom they have a professional responsibility.
With respect to any drug or pharmaceutical products identified, readers are advised to
check the most current information provided (i) on procedures featured or (ii) by the
manufacturer of each product to be administered, to verify the recommended dose or formula,

the method and duration of administration, and contraindications. It is the responsibility of
practitioners, relying on their own experience and knowledge of their patients, to make
diagnoses, to determine dosages and the best treatment for each individual patient, and to
take all appropriate safety precautions.
To the fullest extent of the law, neither the Publisher nor the authors, contributors, or editors,
assume any liability for any injury and/or damage to persons or property as a matter of
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Library of Congress Cataloging-in-Publication Data
Mosby’s pharmacy review for the NAPLEX. -- 1st ed.
p. ; cm.
Other title: Pharmacy review for the NAPLEX
ISBN 978-0-323-04910-8 (pbk. : alk. paper) 1. Pharmacy--Outlines, syllabi, etc. 2. Pharmacy-Examinations, questions, etc. I. Title: Pharmacy review for the NAPLEX.
[DNLM: 1. Pharmaceutical Preparations–Examination Questions. 2. Pharmacy--Examination
Questions. QV 18.2 M8935 2010]
RS98.M72 2010
6150 .1076–dc22
2010003173

Vice President and Publisher: Linda Duncan
Senior Editor: Kellie White
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Publishing Services Manager: Pat Joiner-Myers
Project Manager: Melissa Lastarria
Design Direction: Jessica Williams

Printed in the United States of America.
Last digit is the print number: 9

8 7 6 5 4

3 2 1


..................................................

Contributors

....................................................................................................................................................................

LEAD CONSULTANT
MaryAnne Hochadel, PharmD, BCPS
Editor Emeritus,
ELSEVIER/Gold Standard
Clinical Assistant Professor
University of Florida
College of Pharmacy
Tampa, Florida

CONTRIBUTORS
Catherine Ulbricht, PharmD
Massachusetts General Hospital
Natural Standard Research Collaboration
Somerville, Massachusetts
Erica Rusie, PharmD
Natural Standard Research Collaboration
Somerville, Massachusetts

iii

..................................................

Reviewers

...................................................................................................................................................................

Laurel E. Ashworth, PharmD
Professor of Pharmacy Practice
Mercer University College of Pharmacy and
Health Sciences
Atlanta, Georgia
Paul Juang, PharmD, BCPS
Assistant Professor
Department of Pharmacy Practice
St. Louis College of Pharmacy
St. Louis, Missouri
Julie P. Karpinski, PharmD, BCPS
Director, Drug Information
Assistant Professor, Pharmacy Practice
Concordia, University School of Pharmacy
Mequon, Wisconsin
Trisha LaPointe, PharmD, BCPS
Assistant Professor of Pharmacy Practice
Massachusetts College of Pharmacy and Health
Sciences
Department of Pharmacy Practice
School of Pharmacy-Boston
Boston, Massachusetts
Donna Larson, EdD, MT(ASCP)DLM

Dean of Allied Health
Mt. Hood Community College
Gresham, Oregon
Terri L. Levien, PharmD
Clinical Associate Professor
Pharmacotherapy Department
College of Pharmacy
Washington State University Spokane
Spokane, Washington

iv

David Nissen, PharmD
Pharmacy Informatics
Missouri Baptist Medical Center
St. Louis, Missouri
Lindsay B. Palkovic, PharmD, BCPS
Assistant Professor of Clinical Pharmacy
Philadelphia College of Pharmacy
University of the Sciences in Philadelphia
Philadelphia, Pennsylvania
Puja Patel, PharmD
Drug Information Resident 2009-2010
Mercer University and Solvay Pharmaceuticals
Atlanta, Georgia
Karen J. Tietze, BS, PharmD
Professor of Clinical Pharmacy
Department of Pharmacy Practice and Pharmacy
Administration
Philadelphia College of Pharmacy

University of the Sciences in Philadelphia
Philadelphia, Pennsylvania
Bradley M. Wright, PharmD, BCPS
Assistant Clinical Professor of Pharmacy Practice
Harrison School of Pharmacy
Auburn University
Mobile, Alabama


..................................................

Introduction

....................................................................................................................................................................

®

Mosby’s Pharmacy Review for the NAPLEX reflects the
unique attributes and dynamic role of the pharmacist
in healthcare. The main objective of the text is to
provide a useful, current, and comprehensive review
of relevant pharmacy topics to the candidate in
®
preparation for the NAPLEX examination.
®
Although this text is for use primarily by NAPLEX
candidates, the concise format of the materials would
make an excellent review for pharmacy students,
pharmacy instructors, or for practicing pharmacists.
Users of this guide will benefit from the review of a variety

of topics relating to the science and art of pharmacy
practice, including general reviews of medication
treatments for commonly encountered disease states and
therapeutic areas. Candidates will benefit from keeping
this book handy as they enter practice to provide a quick
go-to reference regarding pharmaceutical calculation
methods, patient counseling, and more.

Key features of this review include:

Electronic flashcards and two mock timed examinations
on the enclosed CD-ROM allow the student to test
comprehension and to demonstrate competency under
®
testing conditions. The NAPLEX s focus on three areas
of pharmaceutical practice is accurately reflected in the
CD-ROM content.

How to Use This Book
It is best for a candidate to approach preparation for
®
the NAPLEX in a logical and orderly manner, with time
given to consistent review of all areas of importance to
the examination. The format of this text will help the
student with his or her review and organization of study.
The subject matter, including patient-based cases, will
®
address all areas of the NAPLEX competency statements,
in roughly the same proportion that they are represented
®

on the NAPLEX examination. The three main areas of
study are:

Over 1,600 NAPLEX -oriented study questions.

Area One: Assure Safe and Effective Pharmacotherapy
and Optimize Therapeutic Outcomes

An easy to follow outline format for each chapter to
organize and quickly overview each area of importance.

Area Two: Assure Safe and Accurate Preparation and
Dispensing of Medications

Pharmacist-oriented questions at the conclusion of each
chapter include thorough rationales at the end of the book
to aid in comprehensive review and study. The rationales
help ensure comprehension and understanding of the
material, rather than focus on direct memorization or
rote review.

Area Three: Provide Health Care Information and
Promote Public Health

®

Patient-based review questions within the therapeutic
review chapters are presented with an emphasis on
appropriate patient counseling by the pharmacist.

After a thorough review of the text contents, the
student can use the CD-ROM to test medication familiarity
and competency under simulated test circumstances. A
well-prepared student who has studied to learn and
understand the material will be able to display his or her
knowledge and will enhance his or her potential for
licensure.

v


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..................................................

Contents

....................................................................................................................................................................

1

Preparing for the NAPLEX

®

. . . . . . . . . . . . 1

SECTION I: PHARMACEUTICAL
PRACTICE

23

Women’s Health Issues . . . . . . . . . . . . . . 247

24

Immunology and Vaccines . . . . . . . . . . . . 258

25

Immunosuppressants . . . . . . . . . . . . . . . 266

2

Pharmaceutical Calculations . . . . . . . . . . . . 3

3

Compounding . . . . . . . . . . . . . . . . . . . 18

4

Drug Information Resources . . . . . . . . . . . 27

SECTION III: CONSUMER-DIRECTED
HEALTHCARE

5

Dispensing . . . . . . . . . . . . . . . . . . . . . 37

26

Nonprescription Products . . . . . . . . . . . . 271

6

Patient Education . . . . . . . . . . . . . . . . . 56

27

Nutrition . . . . . . . . . . . . . . . . . . . . . . 284

7

Herbs and Dietary Supplements . . . . . . . . . 67

8

Laboratory Tests . . . . . . . . . . . . . . . . . 79

SECTION II: PHARMACOTHERAPY
IN PRACTICE

SECTION IV: MISCELLANEOUS
TOPICS IN PHARMACY PRACTICE
AND SCIENCE
28

Basic Pharmacokinetics . . . . . . . . . . . . . 289

29

Pharmacogenomics . . . . . . . . . . . . . . . . 294

30

Toxicology . . . . . . . . . . . . . . . . . . . . . 299

9

Antiinfective Agents . . . . . . . . . . . . . . . . 87

10

Cardiovascular Disorders . . . . . . . . . . . . 103

11

Dermatologic Disorders . . . . . . . . . . . . . 132

12

Common Endocrinologic Disorders . . . . . . . 138

Appendix A

13

Gastrointestinal Disorders . . . . . . . . . . . . 150

Drug Interactions . . . . . . . . . . . . . . . . . . . . 305

14

Geriatrics . . . . . . . . . . . . . . . . . . . . . . 161

15

Human Immunodeficiency Virus/Acquired
Immunodeficiency Syndrome (HIV/AIDS) . . . 175

16

Kidney Disorders . . . . . . . . . . . . . . . . . 180

17

Oncology . . . . . . . . . . . . . . . . . . . . . . 186

18

Pain Management . . . . . . . . . . . . . . . . . 197

19

Psychiatric Disorders . . . . . . . . . . . . . . . 209

20

Respiratory Disorders . . . . . . . . . . . . . . 223

21

Arthritis . . . . . . . . . . . . . . . . . . . . . . . 231

22

Seizure Disorders . . . . . . . . . . . . . . . . . 237

Appendix B
Federal Pharmacy Law . . . . . . . . . . . . . . . . . 308

Appendix C
Foreign Pharmacy Graduate Equivalency
Examination . . . . . . . . . . . . . . . . . . . . . . . 311

Answers and Rationales . . . . . . . . . . . . 313
Index . . . . . . . . . . . . . . . . . . . . . . . 385

vii


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..................................................

Preparing for the NAPLEX

®

1
CHAPTER

....................................................................................................................................................................

GENERAL INFORMATION
NAPLEX
The North American Pharmacy Licensure Exam (NAPLEX)
is the clinical aptitude test developed by the National
Association of Boards of Pharmacy (NABP) and
administered to pharmacy graduates to assess the
competency of candidates for pharmacy practice. It is a
requirement to obtain pharmacy licensure in all 50 states.
MPJE
The Multistate Pharmacy Jurisprudence Examination
(MPJE) is the examination developed by the NABP to test
the candidate’s competency and knowledge of federal
and state pharmacy law. The questions are customized to
the specific law in each state. It is required for a pharmacy
license by 44 states and the District of Columbia.

REGISTRATION
Candidates wishing to register for the NAPLEX with or
without the MPJE must contact the board of pharmacy in
the state they are seeking licensure or their school of
pharmacy and complete a paper examination registration
form for each examination. Candidates may also

choose to register online for the NAPLEX or MPJE at
www.napb.net. Candidates should check the website to
see if their state participates in online registration.
Candidates may submit their registration, paper or
online, before graduation; however, the state board of
pharmacy will authorize eligibility only after all
graduation requirements have been met.
The NAPLEX and MPJE may be taken on the same day,
if time permits; however, it may be beneficial to take the
examinations on separate days due to the diversity of the
material.

FEES
Examination fees:
 NAPLEX: $465 per examination
 MPJE: $185 per examination
For those who wish to change their appointments, an
additional fee of $50 will be charged. Candidates who
withdraw from taking the NAPLEX will receive a partial
refund of $140; those who withdraw from taking the MPJE
will receive a partial refund of $65. Cancellations or

rescheduling the exam must be done at least two business
days before the scheduled appointment.
Fees are payable to the National Association of
Boards of Pharmacy or NABP and submitted in the form
of a money order, bank draft, or certified check.
Personal check or cash is not accepted.
After registration, candidates will receive an
authorization to test (ATT) letter, which confirms the

candidate’s eligibility by the state board of pharmacy.
Upon receipt, candidates can schedule their
appointments for examination and have one year to do so.
The ATT and application expires after one year.
The NABP website, www.nabp.net, can provide the
most current information.

ANSWER FORMAT OF THE NAPLEX
The computer-adaptive NAPLEX examination consists of
185 multiple-choice questions; however, only 150
questions are scored. The remaining 35 are considered
pretest questions, which have no impact on the final
score. These questions are used to help develop future
tests. Because no indication is given to determine the
scored questions versus the nonscored questions, it is to
test-takers’ advantage to answer all questions to the best
of their knowledge.
The test also uses case/scenario-based format (i.e.,
patient profiles) and K-type multiple choice questions in
which three choices are given and candidates select from
five combinations of those three choices:
I. Choice 1
II. Choice 2
III. Choice 3
A. I only
B. III only
C. I and II
D. II, III
E. I, II, III

TEST STRUCTURE OF THE NAPLEX
The NAPLEX has three core areas:
1. Ensure safe and effective pharmacotherapy and
optimize therapeutic outcomes (approximately 54% of
the exam).
2. Ensure safe and accurate preparation and dispensing
of medications (approximately 35% of the exam).

1


2

CHAPTER 1

PREPARING FOR THE NAPLEX

3. Provide health care information and promote public
health (approximately 11% of the exam).
Candidates may refer to the NAPLEX blueprint for more
detailed dissection of the topics covered on the
examination at www.nabp.net.
If the candidate does not pass the exam, he/she may
retake the exam after 91 days for the NAPLEX and after
30 days for the MPJE.

ADMINISTRATION PROCESS
NAPLEX
The NAPLEX has 185 questions to be taken in a 4 hour
and 15 minute time period. There is an optional

10 minute break after approximately two hours of
testing time.
The test is presented in a computer-adaptive testing
format, which means that each answered question will
determine the difficulty of the next. A correctly answered
question in a series will be followed by a harder question.
An incorrect response will be followed by an easier
question.
Every question must be answered in the order it is
presented. The test-taker cannot return to previous
questions and change answers, so all responses are final.
Due to the adaptive nature of the exam, questions also
cannot be skipped because each response determines the
next question.
MPJE
The test consists of 90 questions; only 60 are scored. The
exam is to be taken in two hours with no break.

TEST TAKING STRATEGY
 Arrive to the testing center at least 30 minutes before

the examination to allow time to check-in.
 Take a snack for the 10-minute break during the

NAPLEX.
 Take proper identification (refer to candidate

bulletin).
 Relax the night before the exam and eat a nutritious

breakfast the morning of the examination.
 Although there is no penalty for guessing, you still

want to make your best effort to choose a correct
response.
 Make educated guesses. If you can rule out one or more
answer choices, you have a better chance of selecting
the right answer.
 Limit your time on any one question; as a general
rule of thumb, be halfway through the NAPLEX by the
10 minute break.
 Use various study guide materials, including text
books, flashcards, class notes, and practice tests.
Take a full-length practice test before the
examination.

 Do not try to “cram” new material. Create a study

schedule that allots adequate time for the various
sections of the NAPLEX.

SCORE RESULTS
NAPLEX
The scaled NAPLEX scores range from 0 to 150 with a
minimally acceptable level of performance on the
examination reflected by a score of 75. To obtain a score,
the candidate has to complete at least 162 questions.
Test scores are not given directly to the candidate;
instead, they are forwarded by the NABP to the board of
pharmacy from which the candidate is seeking licensure.

Depending on the state, candidates may transfer
their scores to more than one state. Candidates should
check the website (www.nabp.net) about the score
transfer program. The state to which they wish to
transfer their scores should also be contacted for more
information.
MPJE
The minimum acceptable passing score on the MPJE
scale is 75. To obtain a score, the candidate has to
complete at least 77 questions. MPJE scores cannot be
transferred between states. Candidates must take the law
portion for each individual state in which they are seeking
licensure.

THE PRE-NAPLEX
The NABP also offers the pre-NAPLEX. It is designed to
familiarize the test-taker with the testing experience.
The pre-NAPLEX is the only practice exam written and
developed by the NABP.
There are 50 questions on the pre-NAPLEX and two
forms are available. The cost for each practice
examination is $50. The candidate must register with the
website and set up a username and password. Each
candidate may take the pre-NAPLEX two times but must
complete the first test before starting another one and
pay for each test. The test may be taken with any
computer with Internet access, including at home, a
school, a library, and at any time. The scores are scaled
and interpreted similar to the NAPLEX.

NAPLEX AND MPJE REGISTRATION BULLETIN
A free bulletin regarding the NAPLEX and MPJE is offered
to all candidates. Topics covered include registration
procedures, testing appointment information, NAPLEX
and MPJE administration, NAPLEX and MPJE score
results, the pre-NAPLEX, and NAPLEX score transfer
information. It is available online at />ftpfiles/bulletins/NAPLEXMPJE.pdf or through your state
board of pharmacy.


I

SECTION

PHARMACEUTICAL PRACTICE

..................................................

Pharmaceutical Calculations

2
CHAPTER

....................................................................................................................................................................

SYSTEMS OF MEASURE
Summary of conversion between metric, apothecaries’
and avoirdupois systems:
Note that in the apothecaries’ and avoirdupois systems
there is only one common unit of measure, the grain. The

other measurement units carry different values when
comparing the systems. When converting between the two,
the pharmacist should convert the value down to the grain
amount in the one system, then convert to the other system.
Per the United States Pharmacopeia, 1 grain ¼ 64.8 mg.
METRIC SYSTEM
Mass
¼ gram (g)
Length ¼ meter (m)
Volume ¼ liter (L)
¼ 1 cubic centimeter (cc) equals approximately 1
milliliter (mL) and weighs 1 g

Prefixes
kilohectodekadecicentimillimicronanopico-

103
102
10
10À1
10À2
10À3
10À6
10À9
10À12

1 thousand (1000) times the basic unit
1 hundred (100) times the basic unit
1 ten (10) times the basic unit
1 tenth (0.1) times the basic unit

1 hundredth (0.01) times the basic unit
1 thousandth (0.001) times the basic unit
1 millionth times the basic unit
1 billionth times the basic unit
1 trillionth times the basic unit

APOTHECARIES’ SYSTEM

Volume (fluid)

60 minims
8 drams
16 fluid ounces
2 pints
8 pints (4 quarts)

¼
¼
¼
¼
¼

1
1
1
1
1

fluid drachm (or dram)
fluidounce

pint
quart
gallon

Mass (weight)
12 ounces
8 drams (480 grains)
1 drams

¼ 1 pound
¼ 1 ounce (apothecaries’)
¼ 27.34375 grains

1 dram
3 scruples
20 grains

¼ 1.772 grams
¼ 1 dram
¼ 1 scruple

AVOIRDUPOIS SYSTEM
A system of masses based on a pound weighing 16 ounces
mostly commonly used in the United States for
commercial purposes.

Volume
1 fluid ounce

¼ 8 fluidram

Mass
437:5 grains
¼ 1 ounce
28:349523 grams ¼ 1 ounce
16 drams
¼ 1 ounce ðavoirdupoisÞ
16 ounces
¼ 1 pound ðlb:Þ
UNITS OF AMOUNT OF SUBSTANCE
1 Mole ¼ Molecular Weight in grams or Relative Molecular
Mass in grams
1 Molar solution ¼ Gram Molecular Weight or Relative
Molecular Mass in grams in 1 Liter
1 mol ¼ 1000 millimols (normally written as 1000 mmol)
1 millimole ¼ 1000 micromoles
1 micromole ¼ 1000 nanomoles
1 mol / liter ¼ 1 mmol / mL, 1 mmol / liter ¼ 1 micromole / mL
Millimole (mmol): A millimole (mmol) is a molecular
weight expressed in milligrams.
The number of millimoles of a substance is calculated
by dividing the number of milligrams of a substance by
the molecular weight (MW) of the substance:
mmols ¼ mg/MW

RATIO AND PROPORTIONS
RATIO
A ratio is a comparison of two numbers. In pharmacy
calculations, a ratio can be used to express strength of
drug concentration.

Example: A 1:25 solution of wintergreen oil means that
1 mL of wintergreen oil is contained in each 25 mL of solution.
3


4

SECTION I

PHARMACEUTICAL PRACTICE

PROPORTIONS
A proportion represents the equality between two ratios.
A proportion is an equation with a ratio on each side. It is
a statement that two ratios are equal. This mathematical
concept is often used in community pharmacy.

Example:
If 5 tablets contain 1625 mg of acetaminophen, how many
tablets should contain 2925 mg?

Solution:

5 ðtabletsÞ ¼ 1625 milligrams
X ðtabletsÞ ¼ 2925 milligrams
X ¼ 9 tablets; answer
5 tablets X tablets
¼
1625 mg
2925 mg

X ¼ 9 tablets

Relevant measurements and conversions
1 in
¼ 2.54 cm
1m
¼ 39.37 in
1 kg ¼ 2.2 lb
1g
¼ 15.4324 gr (round to 15.4 gr)
1 fl oz. ¼ 29.5729 mL (round to 29.6 or 30 mL)

DIMENSIONAL ANALYSIS
Dimensional analysis is a method of manipulating units to
solve mathematical equations. The process allows you to
cancel out unwanted units leaving only those units you
want your answer to be expressed as.

Example:
A pharmacist wants to know how many inhalers should
be dispensed to a patient to provide a 60-day
supply of fluticasone. The recommended daily dose
is 250 mcg twice daily. The commercial inhaler delivers
220 mcg per metered dose and contains 60 metered
inhalations.

Solution:

220 mcg  2 (twice daily) ¼ 440 mcg/day

440 mcg
day

1 inhalation
220 mcg

1 inhaler

 60 days ¼ 2 inhalers
60 inhalations

The pharmacist should dispense 2 inhalers for a 60-day
supply.

INTERPRETATION OF MEDICATION ORDERS
Example 1:
A prescription for prednisone 5 mg should be taken as
follows:
2 tablets three times daily the first day; 1 tablet three
times daily on the second day; 1 tablet twice daily for
7 days; and 1 tablet daily thereafter.
How many tablets should be dispensed for a 30-day supply?

Solution: Dispense 44 tablets in total

Example 2:
A prescription is to be taken as follows: “1 tablespoon ac
and hs for 7 days.” What is the minimum volume that
should be dispensed?

Solution:

achs ¼ before meals and at bedtime
1 tablespoon ¼ 15 mL
Patient needs to receive four doses per day for 7 days.
15 mL  4 doses  7 days ¼ 420 mL

DOSAGE BASED ON DROPS
Certain medications that are administered or dispensed to
a patient come in the form of liquids and are administered
as drops. This section provides practice for calculations
for these types of prescriptions.
If a pharmacist counted 30 drops of a drug in filling a
graduated cylinder to the 1.5 mL mark, how many drops
per milliliter did the dropper deliver?

Solution:
30 drops ðgttÞ 1:5 mL
¼
X gtts
1 mL
X ¼ 20 drops per mL; answer

PERCENTAGE AND RATIO STRENGTH CALCULATIONS
EXPRESSED AS V/V, W/W, AND W/V
Certain prescriptions are expressed in weight/weight
(w/w), volume/volume (v/v), and weight/volume (w/v)
percentages. To properly process prescription orders of
this nature, the pharmacist must be able to make

conversions and calculations with these units.
Concentration ¼ quantity of solute divided by the
quantity of preparation.
V/V: If the solute and the preparation are expressed in
the same units, then concentration is dimensionless.
For example, 10 mL of alcohol dissolved in a sufficient
quantity of water to make 40 mL of solution is
dimensionless: 10 mL/40 mL¼ 0.250 (or 25% v/v).
W/W: If the quantity of solute and of the preparation are
expressed in the same units of weight, the concentration
is dimensionless. If 10 g of charcoal are mixed with 65 g
of another powder to make a total of 75 g, the charcoal
concentration is 10 g/75 g ¼ 0.133 by weight (or 13.3% w/w).
W/V: When a solute is measured by weight and the
solution by volume, concentration is not dimensionless.
If 1.25 g of NaCl is dissolved in sufficient water to make
55 mL of solution, the concentration is 1.25 g/55 mL ¼
0.0227 g/mL (w/v). The % w/v is expressed as #g/100 mL
(e.g., 2.27% or 2.27 g/100 mL).

Example 1:
How many grams of drug should be used to prepare 120
grams of a 2% w/w solution in water?

Solution:
2 grams drug
100 grams drug
¼ 2:4 grams, answer

120 grams mixture Â

CHAPTER 2

Example 2:
What is the percentage strength (w/v) of a solution of
drug if 40 mL contain 5 grams?

The coal tar (active ingredient) is added to a diluent
(petroleum) currently containing no coal tar.
25% 240 grams
¼
15%
X grams
X ¼ 143.7 grams
144 grams of coal tar, answer

40 mL
100 ð%Þ
¼
5 grams
X ð%Þ

PPM AND PPB (PARTS PER MILLION AND PARTS
PER BILLION)
When ppm or ppb is used as a designation for
concentration, some systems are w/w, some are v/v and
some are w/v. Concentration is always a ratio or fraction
in w/w and v/v situations. Weight by volume (w/v)
concentrations are always defined in terms of grams and

milliliters. The same default rules are followed as for
percentage systems.

Example:
Express 2 ppm of ferrous gluconate in water in percentage
strength and ratio strength.

Solution:

2 ppm ¼ 2 parts in 1,000,000 parts
¼ 1:500,000 À ratio strength
0.0002% À percentage strength

DILUTION, CONCENTRATION, AND ALLIGATION
DILUTION OF AN INGREDIENT
Dilution is the addition of diluent to the ingredient or an
admixture of the ingredient with solutions to achieve a
lower concentration of solution.

Example:
A 1:5000 dilution of drug A is requested. If 1 mL of drug A
injection 1:200 is mixed with sterile water for injection,
how many mL of water will be needed?

ALIQUOT METHOD (ALLIGATION)
Alligation is a method that is particularly useful when
mixing two or more preparations of known strengths to
prepare a mixture of an intermediate desired strength.
The final mixture will be an average of the individual
strengths, which are calculated as proportional parts.

Alligation Alternate and Alligation Medial are methods
that can be used to solve any type of dilution or
concentration problem, including concentrations
expressed in mg/mL, ratios, mixtures of liquids of known
specific gravities, etc. The strengths of all preparations
being mixed and the final mixture are expressed in a
common denomination (of weight, volume, percentage,
etc.) when setting up the alligation equation. When
diluting a preparation, the strength of the diluent is
considered to be 0%. When increasing the strength of a
given mixture by adding more drug/active ingredient, the
strength of the active ingredient to be added is
considered to be 100%. A final proportion allows a
correlation between the parts and any specific
denomination needed.

Example 1:
A pharmacist has a 60% solution and a 15% solution.
She needs a 40% solution to compound a medication.
What is the proportion of the 60% and 15% solutions that
would make a 40% solution? This example will use the
process of Alligation Alternate to calculate the quantities
of each mixture needed to make the final mixture of the
desired strength:

Solution:
60%

1
1

1 mL ¼
ðXÞ
200
5000
0.005 ¼ 0.0002(X)
25 mL ¼ X
25 mL À 1 mL ¼ 24 mL, answer
CONCENTRATION OF AN INGREDIENT
Concentration is the addition of an active ingredient or
evaporation of the diluent from an active ingredient to
create a more concentrated solution.

Example:
How many grams of coal tar containing 25% (w/w) should
be added to petrolatum to prepare 240 grams of coal tar
containing 15% (w/w)?

25

60 À 40 ¼ 20
15 À 40 ¼ 25

40%
15%

Solution:

5

Solution:

Solution:

X ¼ 12:5%; answer

Pharmaceutical Calculations

20 parts

25 þ 20 ¼ 45

25 parts of the 60% solution combined with 25 parts of
15% solution would yield 45 parts of a 40% solution.

ISOTONIC SOLUTIONS
Osmosis occurs when a solvent (e.g.,water) passes
through a semipermiable membrane from a lowconcentration solution into a high-concentration one, with
the result that the concentrations become equalized.
The pressure that causes this occurrence is known as
osmotic pressure.
A solution that exerts the same osmotic pressure
as a specific body fluid is known as isotonic. If the
solution exerts an osmotic pressure lower than that of
specific body fluid, the solution is hypotonic. If the actual
solution exerts an osmotic pressure higher than that of
specific body fluid, the solution is considered hypertonic.


6

SECTION I

PHARMACEUTICAL PRACTICE

Example:

Example:

How much sodium chloride is needed to adjust the
following prescription to isotonicity? (E value [sodium
chloride equivalents] for zinc sulfate is 0.15)
Zinc sulfate 2%
NaCl
q.s.
Purified water q.s. 60 mL
Make isotonic solution

How much calcium chloride (CaCl22H2O) is required to
prepare 100, 1 mL ampules containing 10 mEq per mL?
(mw ¼ 147)

Solution:

100 mL Â 10 mEq=mL ¼ 1000 mEq
1 mEq ¼

Solution:

1 mEq
1000 mEq

¼
¼ 73; 500 mg
73:5 mg
X

If sodium chloride is only being used to provide the 60 mL
isotonic solution: 60 mL Â 0.9% ¼ 0.54 g (or 540 mg)
Step 1: 60 mL Â 2% ¼ 1.2 g (or 1200 mg) of zinc sulfate
required to fill the prescription
Step 2: 1200 mg is equivalent to 1200 Â 0.15 ¼ 180 mg
of sodium chloride
Step 3: 540 mg À 180 mg ¼ 360 mg (or 0.36 g), answer

ELECTROLYTE SOLUTIONS
Electrolyte solutions are used to treat fluid and electrolyte
disturbances. They may be prepared as oral solutions,
syrups, dry granules intended to be dissolved in water or
juice to make an oral solution, or oral tablets or capsules, and
they are also commonly prepared as intravenous infusions.
To convert electrolytes in solution (expressed as
milliequivalents [mEq] per unit volume to weight per unit
volume or vice versa), the following calculation may be used:
mg  Valence
mEq ¼
Atomic; molecular; or formula weight
mg ¼

mEq  Atomic; molecular; or formula weight
Valence

Table 2-1

Valences and Atomic Weights of Select Ions

Ion

Formula

Aluminum
Ammonium
Acetate
Bicarbonate
Calcium
Carbonate
Chloride
Citrate
Ferrous
Ferric
Gluconate
Lactate
Lithium
Magnesium
Phosphate
(mono)
Phosphate (di)
Potassium
Sodium
Sulfate

Al3þ

NH4þ
C2H3O2À
HCO3À
Caþ2
CO32À
ClÀ
À
C6H5O73
2þ
Fe
Fe3þ
C6H5O3À
C3H5O3À
Liþ
Mg2þ
H2PO4À
HPO42À
Kþ
Naþ
SO42À

Atomic/Formula
Weight

Valence

27
18
59
61

40
60
35.5
189
56
56
195
89
7
24
97

3
1
1
1
2
2
1
3
2
3
1
1
1
2
1

96
39

23
96

2
1
1
2

From Zatz J: Pharmaceutical Calculations, ed 4, Hoboken, NJ,
2005, John Wiley & Sons, Inc., p. 267.

147 mg
¼ 73:5 mg
2

X ¼ 73:5 g, answer

TPN CALCULATIONS
Total parenteral nutrition (TPN) provides all of the
patient’s daily nutritional requirements and generally
contains dextrose (carbohydrate), amino acids (protein
source), vitamins, trace minerals, electrolytes, and fat
emulsions. TPN solutions may also include insulin and
occasionally therapeutic drugs. The amount of protein,
dextrose, and fat are calculated based on the patient’s
daily kcal (calories) needed and available stock solutions.
Other ingredients do not contain calories.

Example:
A patient needs 1600 kcal/day. The physician has

ordered that the patient receive 65% of the daily calories
(kcal) from carbohydrates, 10% from protein, and 25%
from fat.
Calculate the amount (volume) needed to supply the
dextrose, protein, and fat calories from these pharmacy
stock solutions:
Dextrose 65%, amino acid 10%, fat 25%
First, determine how many kcal the patient needs from
each component:
1600 kcal  65% ¼ 1040 kcal from dextrose
1600 kcal  10% ¼ 160 kcal from protein
1600 kcal  25% ¼ 400 kcal from fat
Next, convert these kcals into grams:
1040 kcal  1 gram=3:4 kcal ¼ 305:9 grams dextrose
160 kcal  1 gram=4 kcal ¼ 40 grams protein
400 kcal  1 gram=9 kcal ¼ 44 grams fat
Then, calculate how many milliliters are needed from
each stock solution:
305.9 grams  100 mL/ 65 grams ¼ 470.6 mL from
dextrose 65%
40 grams  100 mL/ 10 grams
¼ 400 mL from amino
acid 10%
44.4 grams  100 mL/ 25 grams ¼ 177.6 mL from fat 25%
NOTE:
Carbohydrate contains 3.4 kcal/g
Amino acid contains 4 kcal/g
Fat contains 9 kcal/g

CALCULATION OF DOSES

There are a variety of ways to determine doses of drugs
including by age, body weight, surface area, creatinine
clearance, and other pharmacokinetic parameters.


CHAPTER 2

CREATININE CLEARANCE
When using the below equations, two factors to consider
are (1) the serum creatinine is at steady state and (2) the
weight, gender, and age of the individual reflect normal
muscle mass.
Cockcroft-Gault equation
To estimate renal function for the purpose of drug
dosing, creatinine clearance should be measured or
estimated.

For males:
CrCl ¼

ð140 À Patient0 s age in yearsÞ Â Body weight in kg
72 Â Serum creatinine in mg=dL

For females:
CrCl ¼ 0:85 Â CrCl determined using formula for males
If the individual is obese or not within 30% of their ideal
body weight, other methods of calculating creatinine
clearance should be used. Ideal body weight (IBW) or
adjusted body weight (ideal body weight plus 40% of
obese weight) instead of actual body weight in the

Cockcroft-Gault equation will provide a better estimate
of creatinine clearance.

The average BSA of an adult is 1.73 m2.

CALCULATIONS FOR PEDIATRIC DOSES
Various pediatric formulas have been used historically to
calculate APPROXIMATE pediatric dosages.
Young’s rule, based on age:
Age
 Adult dose ¼ Dose for child
Age þ 12
Fried’s rule for infants:
Age ðin monthsÞ
 Adult dose ¼ Approx: dose for infant
150

Clark’s rule, based on weight:
Weight ðin lbÞ Â Adult dose
¼ Dose for child
150
BSA approximation of child’s dose:
Child BSA
 Adult dose ¼ Approx: dose for child
1:73 m2

7

STOCK SOLUTIONS
A stock solution, commonly referred to as bulk bottle, is a

large volume of a reagent (in chemistry) or in this case,
medication. These stock solutions can be prepared by a
manufacturer or compounded in the pharmacy.
Pharmacists typically take stock solutions and use them
to prepare weaker solutions of medications or chemicals
for laboratory or clinical use.

Example:
How many mL of a 0.5% gentian violet stock solution is
needed to prepare 1 pint of a 1:2000 solution?

Solution:
Step 1: Determine the quantity of the final solution:
1 pint ¼ 946 mL,
so

1g
X grams
¼
200 mL
946 mL
X ¼ 0:473 grams

Step 2: Determine the amount of available solution needed
to obtain the determined quantity (0.5% gentian violet
solution contains 0.5 grams in 100 mL of solution):
0:5 g
0:473 grams
¼
100 mL

X mL
X ¼ 94:6 mL; estimate 95 mL

IBW for males in kg ¼ 50 þ (2.3)(Height in inches > 60)
IBW for females in kg ¼ 45 þ (2.3)(Height in inches > 60)

BODY SURFACE AREA
The practioner may need to take into account body
surface area as a possible variable when determining drug
dosage (e.g., chemotherapy).
Body Surface Area (BSA) – The Mosteller Formula:
rffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi
Height ðcmÞ Â Weight ðkgÞ
2
BSAðm Þ ¼
3600

Pharmaceutical Calculations

RECONSTITUTION OF DRY POWDERS
Many drugs (antibiotics, steroids, and biologics) that are not
stable in solution are prepared as dry-filled solids or
lyophilized powders. Prior to use, these dry powders must
be reconstituted as a solution with a suitable diluent in the
proper volume to give specified concentration (usually
provided in the package insert). Occasionally, the physician
may prescribe a final concentration different from the one
provided by the manufacturer. Also, in some cases, the
pharmacist needs to determine if the powdered drug
contributes to the final volume of the reconstituted solution

before modifying the label instructions.

Example:
The package information of a vial containing 30 million
units of penicillin G potassium specifies that when the
appropriate amount of sterile solvent is added to dry
powder, the resulting concentration is 500,000 units per
mL. How many milliliters of sterile water for injection
are needed to prepare the following solution?
(Note: the powder accounts for 8 mL of the final volume)
Penicillin G potassium 30,000,000 units
Sterile water for injection
Provide a solution containing 500,000 units per mL
500; 000 units
1 mL
¼
30; 000; 000 units X mL
X ¼ 60 mL
60 mL À 8 mL ¼ 52 mL, answer


8

SECTION I

PHARMACEUTICAL PRACTICE

INTRAVENOUS INFUSIONS, PARENTERAL
ADMIXTURES, AND FLOW RATES
Intravenous infusions are large volumes of sterile,

aqueous preparations administered intravenously
(through a vein) over an extended period of time.

Example:
An order is written for 25,000 units of heparin in 250 mL of
D5W to infuse at 2000 units/hr. What is the correct rate of
the infusion (in mL/hr)?

Solution:
Concentration of IV ¼
IV rate ¼
Concentration of IV ¼

Total amount of drug
Total volume
Dose desired
Concentration of IV
25;000 units of heparin
250 mL of D5W

Concentration of IV ¼ 100 units=mL of heparin
2000 units=hr
IV rate ¼
100 units=mL
IV rate ¼ 20 mL=hr

References
Ansel H, Stoklosa M: Pharmaceutical Calculations, ed 12,
Baltimore, MD, 2005, Lippincott Williams & Wilkins.
Bhatt SHL: Aminoglycoside Pharmacokinetics and

Therapeutics, MCPHS Boston Campus, MA, 2006, White
Hall.
Institute of the Certification of Pharmacy Technicians
(ICPT): ExCPT Exam for the Certification of Pharmacy
Technicians. Available at ionaltechexam.
org/pdf/math_questions-answers070618.pdf, Accessed
December 24, 2008.
London, Eastern and South East Specialist Pharmacy
Services. Available at .
uk/educationandtraining/prereg/supportMaterial/
calculations/download/Calculations%20WorkBook%
202005.pdf, Accessed December 24, 2008.
Pearson J, Powers M: Systematically Initiating Insulin. The
Staged Diabetes Management Approach, Diabetes Educ
32(Suppl 1):23s, 2006.
Shargel L: Applied Biopharmaceutics & Pharmacokinetics,
New York, 2005, McGraw-Hill Medical Publishing
Division, pp 43–46.
Zatz J: Pharmaceutical Calculations, ed 4, Hoboken, NJ,
2005, John Wiley & Sons, Inc, pp 30–33.
Mosteller RD: Simplified Calculation of Body Surface Area,
N Engl J Med 317:1098, (letter) 1987.

Parenteral admixtures are a sterile preparation that involves
the combination of one or more drugs to large-volume.

REVIEW QUESTIONS

Example:

(Answers and Rationales on page 313.)

A patient weighs 170 pounds. A pharmacist receives a
prescription order for 0.25 mg amphotericin B per
kilogram body weight. How many milliliters of a 25 mg/
10 mL solution are needed to supply the dose, which will
then be diluted in 500 mL of 5% dextrose?

Solution:
170 lb
¼ 77 kg patient
2:2 lb
0:25 mg  77 kg ¼ 19:25 mg dose needed
25 mg
10 mL
¼
19:25 mg
X mL
X ¼ 7:7 mL, answer
Calculating IV flow or drip rates are necessary to ensure
that the patient is receiving the desired amount of drug
that was ordered.

Example:
If 20 mg of drug is added to a 750 mL parenteral fluid, what
flow rate, in millilters per hour, will deliver 2 mg of drug
per hour?

Solution:
20 mg 750 mL

¼
2 mg
X mL
X ¼ 75 mL per hour, answer

1. A patient is prescribed 10 mEq of potassium daily.
The source of potassium chloride in the pharmacy
is 5 mEq/mL in 1 mL vials. How many vials per day is
needed for the patient?
a. 0.5 vial
b. 1 vial
c. 2 vials
d. 1.5 vials
2. How much elemental iron is present in every
150 mg of ferrous sulfate (FeSO4  7H2O)?
(Atomic weights are iron ¼ 55.9; sulfur ¼ 32.1;
oxygen ¼ 16.0; and hydrogen ¼ 1.0. Iron has
valences of þ2 and þ3)
a. 25 mg
b. 30 mg
c. 48 mg
d. 54 mg
e. 60 mg
3. A 130-lb patient has a creatinine clearance rate
of 40 mL/min. Assuming Drug X is eliminated
exclusively by renal mechanisms, what maintenance
dose should be administered if the normal
maintenance dose is 3 mg/lb of body weight?
a. 50 mg
b. 100 mg

c. 150 mg
d. 200 mg
e. 250 mg


CHAPTER 2

4. An IV medication is available as 3.5 g/ 500 mL with
a strength calculation of 0.25 mg/kg/min is
prescribed to a 130-lb patient. What is the infusion
rate in mL/hour?
a. 2.1 mL/ hr
b. 126.6 mL/ hr
c. 278.6 mL/ hr
d. 6,203.4 mL/ hr
5. Which of the following is an invalid DEA number?
a. BT5555555
b. DB1294658
c. AR7532648
d. MA2643713
e. All of the above are valid
6. How many quarts are in two gallons?
a. 2 quarts
b. 4 quarts
c. 8 quarts
d. 16 quarts
7. How many fluid ounces are in a quart?
a. 4 fluid ounces
b. 8 fluid ounces
c. 16 fluid ounces

d. 32 fluid ounces
8. How many teaspoons are in one pint?
a. 31.5
b. 47.3
c. 94.6
d. 104.2
9. A patient is prescribed 20 mEq of potassium
chloride daily. The source of potassium chloride
in the pharmacy is 2 mEq/ mL in 20 mL vials.
How many mL per day are needed for this patient?
a. 1 mL
b. 2 mL
c. 10 mL
d. 20 mL
10. A patient is prescribed 10 mEq of potassium
chloride daily. The source of potassium chloride in
the pharmacy is 2 mEq/ mL in 20 mL vials. How
many mL per day are needed for this patient?
a. 0.5 mL
b. 1 mL
c. 5 mL
d. 10 mL
11. How much sodium chloride is needed to make an
isotonic 100 mL solution?
a. 0.45 g
b. 0.90 g
c. 1.32 g
d. 1.53 g
12. What volume of diluent (assume sterile water) is
needed to make an isotonic solution from 0.45 g of

sodium chloride?
a. 25 mL
b. 50 mL

c.
d.

Pharmaceutical Calculations

9

100 mL
125 mL

13. The ratio strength of a solution is 1:900 (w/v).
What is the percent weight by volume [(w/v)%] of
the solution?
a. 0.1%
b. 1.1 %
c. 0.9%
d. 9%
14. The ratio strength of a solution is 1:5000 (w/v).
What is the percent weight by volume [(w/v)%] of
the solution?
a. 0.02%
b. 2 %
c. 0.8%
d. 8%
15. A vial of tobramycin sulfate contains 40 mg of drug
per mL of injection. A patient was given 0.5 mL.

How much tobramycin sulfate was administered?
a. 10 mg
b. 20 mg
c. 30 mg
d. 40 mg
16. How many days will the following prescription supply?
Rx
Penicillin VK suspension 250 mg/5 mL
Sig. 1 tsp. qid t.a.t. disp 200 mL
a. 7 days
b. 10 days
c. 14 days
d. 21 days
17. A medication is available in a 200 mg/5 mL vial. An
Rx calls for 150 mg bid  10d.
How many milliliters are needed for a single day?
a. 5 mL
b. 7.5 mL
c. 10 mL
d. 75 mL
18. A medication is available in a 200 mg/5 mL
multiple-use vial. An Rx calls for 300 mg
bid  10d.
How many vials are needed for the full course?
a. 15 vials
b. 30 vials
c. 60 vials
d. 75 vials
19. JK is a 42 year-old woman who has a prescription for
32 mEq of oral potassium chloride. However, your

pharmacy only has 600 mg controlled-release
potassium chloride tablets in stock. How many
tablets are required each day to provide this dose?
(MW ¼ 75)
a. 8
b. 3
c. 2
d. 4
e. 6


10

SECTION I

PHARMACEUTICAL PRACTICE

20. If a patient has a temperature of 102.2 F, what is the
patient’s temperature in degrees Celsius?
a. 37.6  C
b. 38.4  C
c. 39  C
d. 40.1  C
21. If 500 mL of a 15% (v/v) solution of methyl salicylate
in alcohol is diluted to 1500 mL, what will be the
percentage strength (v/v)?
a. 225%
b. 5%
c. 45%
d. 0.45%

22. A medication is available in a 150 mg/5 mL vial.
An Rx calls for 300 mg bid  10d.
How many mL are needed for a single dose?
a. 5 mL
b. 10 mL
c. 50 mL
d. 100 mL
23. What is the day supply for this prescription?
Amoxicillin 125 mg/5 ml (100 ml)
SIG: ss tsp tid
a. 2 days
b. 100 days
c. 25 days
d. 13 days
e. 10 days
24. What is the percent weight by volume [%(w/v)] if
250 grams of dextrose is dissolved in 300 mL of
water to make a final volume of 500 mL?
a. 4.5%
b. 5%
c. 45.45%
d. 50%
25. If a prescription reads “Dispense: XVIII capsules,”
how many capsules should be dispensed?
a. 12 tablets
b. 18 tablets
c. 22 tablets
d. 30 tablets
26. What total quantity of tablets should be dispensed
for the following prescription?

Rx: Prednisone 5 mg
Sig: 10 mg qid  2 days
10 mg tid  2 days
10 mg bid  2 days
5 mg tid  2 days
5 mg bid  2 days Then stop.
Qty qs
a. 23 tablets
b. 25 tablets
c. 46 tablets
d. 50 tablets
27. What quantity should be dispensed for the following
prescription?

Rx: Prednisone 10 mg
Sig: 2 tabs bid  3 days
1 tab bid  3 days
1 tab qd  3 days
1/2 tab qd  3 days Then stop.
Qty qs
a. 9 tablets
b. 10 tablets
c. 22 tablets
d. 23 tablets
28. How many grams of NaCl are there in
1000 mL of D5W/0.45% NaCl solution?
a. 4.5 g
b. 0.6 g
c. 0.45 g
d. 0.25 g

29. How many grams of dextrose are in 1000 mL of D5W/
0.45% NaCl solution?
a. 100 g
b. 50 g
c. 20 g
d. 15 g
30. How many grams of dextrose are in 500 mL of a 10%
dextrose solution?
a. 500 g
b. 50 g
c. 150 g
d. 200 g
31. How many grams of NaCl are in 500 mL of 0.9%
sodium chloride (NS) solution?
a. 5 g
b. 2.5 g
c. 4.5 g
d. 1.5 g
32. How many milligrams of neomycin are in 25 mL of a
1% neomycin solution?
a. 250 mg
b. 125 mg
c. 400 mg
d. 500 mg
33. How many grams of amino acids are in 500 mL of a
5% amino acid solution?
a. 2.5 g
b. 22.5 g
c. 25 g
d. 50 g

e. 10 g
34. A pharmacist has 25 mL of 0.5% gentian violet
solution. What will be the final ratio strength if he
or she dilutes this solution to 600 mL with purified
water?
a. 1:8
b. 1:200
c. 1:500
d. 1:1000
e. 1:4800


CHAPTER 2

Pharmaceutical Calculations

35. An order is written for 1 g of lidocaine in 250 mL of
D5W to infuse at 60 mg/hr. What is the correct
infusion in (mL/hr)?
a. 15 mL/hr
b. 20 mL/hr
c. 35 mL/hr
d. 45 mL/hr

43. How many milliliters contain 2.5 g of
cephalothin if the concentration of the solution
is 1 g/4.5 mL?
a. 16.5 mL
b. 13.5 mL
c. 14.25 mL

d. 11.25 mL

36. An order is written for 25,000 units of heparin in
250 mL of D5W to infuse at 17 mL/hr. How many
units of heparin will the patient receive in
6 hours?
a. 10,200 units
b. 40,000 units
c. 10,800 units
d. 20,400 units

44. How many grams of iodine are in 4 mL of a 50%
iodine solution?
a. 1 g
b. 2 g
c. 3 g
d. 4 g

37. An order calls for 2.5 million units of aqueous
penicillin. How many milliliters are needed if the vial
concentration is 500,000 units/mL?
a. 6 mL
b. 2 mL
c. 10 mL
d. 5 mL
38. How many milliliters are needed for 5 million units
of penicillin if the vial concentration is 1 million
units per mL?
a. 15 mL
b. 5 mL

c. 10 mL
d. 20 mL
39. Valproic acid syrup comes in a 250 mg/5 mL
concentration. How many mg are present in 7.5 mL
of solution?
a. 1000 mg
b. 500 mg
c. 375 mg
d. 250 mg
40. How many milliliters of 250 mg/5 mL valproic acid
syrup are needed for a 0.5-g dose?
a. 1 mL
b. 5 mL
c. 10 mL
d. 15 mL
41. If a drug comes in a 250 mg/1.5 mL solution, how
many milliliters are required for a 2 g dose?
a. 1.5 mL
b. 2 mL
c. 4.5 mL
d. 6 mL
e. 12 mL
42. How many grams of ampicillin are in 3 mL of a
500 mg/1.5 mL solution?
a. 1 gram
b. 4 grams
c. 3.5 grams
d. 2 grams

11

45. How many milliliters of a 50% dextrose solution are
needed for a 7.5-g dextrose dose?
a. 7.5 mL
b. 10 mL
c. 15 mL
d. 20 mL
46. How many grams of sodium are in 50 mL D5W
solution?
a. 0
b. 1
c. 2.5
d. 3
47. The unit of weight measurement that is the
same in both the apothecaries’ and avoirdupois
systems is the?
a. Dram
b. Grain
c. Ounce
d. Pound
e. Scrupple
48. One microgram equals one thousand (1000):
a. Centigrams
b. Grams
c. Kilograms
d. Nanograms
e. Milligrams
49. Calculate the drip rate for 120 mL of IV fluids to be
given over a half hour via an IV set that delivers
15 gtt/mL.

a. 13 gtt/min
b. 25 gtt/min
c. 60 gtt/min
d. 33 gtt/min
e. 50 gtt/min
50. If a patient is given IV fluids at a rate of 25 gtt/min
over 1 hour, how much fluid will be administered?
The drop factor is 15 gtt/ml.
a. 50 mL
b. 100 mL
c. 125 mL
d. 200 mL
e. 225 mL


12

SECTION I

PHARMACEUTICAL PRACTICE

51. In order to achieve better pain control, codeine
phosphate 0.7 mL SC Â 1 is ordered for a patient.
The injectable form of codeine phosphate is
available in a concentration of 50 mg/mL. How much
codeine will this patient receive in this dose?
a. 20 mg
b. 30 mg
c. 35 mg
d. 60 mg

e. 100 mg
52. Morphine is ordered for a patient, and the nurse
gives him 1.9 mL from a vial with a concentration of
40 mg/2.5 mL. How much morphine was the patient
given?
a. 5 mg
b. 10 mg
c. 20 mg
d. 30 mg
e. 40 mg
53. The vial of hydromorphone that you have in stock
has a concentration of 1.5 mg/0.5 mL. If the patient is
given 0.7 mL, how much hydromorphone did she
receive?
a. 1. 8 mg
b. 2.1 mg
c. 2.2 mg
d. 2.4 mg
e. 3 mg
54. What is the concentration (in percent) of a solution
containing 20 mEq of potassium chloride per 15 mL
of liquid? (MW ¼ 75)
a. 10
b. 15
c. 20
d. 25
e. 2.5
55. Diazepam is to be administered by the IV route
to an adult patient. It is given at a rate of 5 mg/min
over 90 seconds. How much diazepam is given to this

patient?
a. 5 mg
b. 6 mg
c. 7.5 mg
d. 8 mg
e. 10 mg
56. How many milligrams of morphine were given to a
patient who received 6.2 mL of a 5 mg/mL solution?
a. 31 mg
b. 22 mg
c. 25 mg
d. 35 mg
e. 46 mg
57. A nurse wants to give 300 mcg of levothyroxine
IV to a patient, from a vial containing 0.4 mg/mL.
How many milliliters should be given to
the patient?

a.
b.
c.
d.
e.

0.6 mL
0.8 mL
1.0 mL
1.2 mL
7.5 mL

58. A patient is to take 2.6 mL of oral furosemide, and
each teaspoon contains 40 mg. How much
furosemide will the patient be taking in their 2.6 mL
dose?
a. 20.8 mg
b. 40 mg
c. 33.1 mg
d. 16.5 mg
e. 24 mg
59. What is the percent weight=weight (%[w/w]) if
250 grams of dextrose is dissolved in 300 mL of
water to make a final volume of 500 mL?
a. 4.5%
b. 5%
c. 45.45%
d. 50%
60. According to USP specifications, how many
milligrams is equal to 1/2 grain?
a. 64.8 mg
b. 32.4 mg
c. 32.4 g
d. 3.24 mg
61. If the adult dose of a drug is 200 mg, what is the
estimated dose for a child with a BSA of 0.8 m2, using
the BSA estimation method?
a. 92 mg
b. 150 mg
c. 50 mg
d. 75 mg
62. If Lanoxin Pediatric Elixir contains 0.1 mg of

digoxin per mL, how many mcg of digoxin are
in 6 mL elixir?
a. 6 mcg
b. 60 mcg
c. 600 mcg
d. 6000 mcg
63. What is the percentage of alcohol in a mixture of
200 mL of 95% v/v alcohol, 1000 mL of 70% v/v
alcohol, and 200 mL of 80% v/v alcohol?
a. 75%
b. 82%
c. 0.75%
d. 7.5%
64. A TPN order requires 500 mL of D5W. How many
mL of D50W should be used if the D5W is not
available?
a. 450 mL
b. 550 mL
c. 50 mL
d. 25 mL


CHAPTER 2

65. How much sodium chloride is needed to make the
following prescription isotonic given E value for zinc
sulfate is 0.15?
Zinc sulfate 2%
Sodium chloride q.s.
Purified water q.s 60 mL

a. 540 mg
b. 1200 mg
c. 180 mg
d. 360 mg
66. How much elemental iron is present in 500 mg
of ferrous sulfate (FeSO4  7H2O) with atomic
weights are Fe ¼ 55.9; sulfur ¼ 32.1; oxygen ¼ 16.0;
and hydrogen ¼ 1.0. Iron has valences of
þ2 and þ3)?
a. 100.5 mg
b. 167.7 mg
c. 111.8 mg
d. 120 mg
67. What will be the final ratio strength of a solution if
one wishes to dilute 100 mL of 0.5% gentian violet
solution to 1250 mL with purified water?
a. 1:500
b. 1:1000
c. 1:2500
d. 1:5000
68. How many beclomethasone (Qvar) inhalers should
be dispensed to provide a 90-day supply? The
recommended dose is 168 mcg BID. The commercial
inhaler delivers 42 mcg per metered dose and
contains 200 inhalations
a. 2 inhalers
b. 3 inhalers
c. 4 inhalers
d. 5 inhalers
69. If 6.25 g of boric acid are dissolved in sufficient

alcohol to make a total volume of 100 mL, what is the
strength of boric acid in the solution in mg/mL?
a. 62.5 mg/mL
b. 6.25 mg/mL
c. 625 mg/mL
d. 62.5 g/mL
70. If 50 mL of 4% (w/v) Xylocaine solution are added
to 100 mL bag of D5W injection, what is the
percentage strength (w/v) of Xylocaine in the final
product?
a. 1%
b. 2.5%
c. 1.3%
d. 2%
71. A blood glucose reading shows 200 mg% of glucose.
Express this value in mg/mL.
a. 0.2 mg/mL
b. 20 mg/mL
c. 2 mg/mL
d. 200 mg/mL

Pharmaceutical Calculations

13

72. How many grams of solute are there in 250 g of a
1:50 w/w solution?
a. 50 g
b. 5 g
c. 0.5 g

d. 5 mg
73. How many milligrams of drug are there in 50 mL of a
5% w/v solution?
a. 0.25 g
b. 5 g
c. 2500 mg
d. 250 mg
74. How many milligrams of drug are there in 100 g of a
1:200 w/w mixture?
a. 500 mg
b. 5 mg
c. 5 g
d. 5000 mg
75. How many mg of sodium bicarbonate (NaHCO2)
contain 400 mg of sodium?
a. 1496 mg
b. 1.496 mg
c. 0.922 mg
d. 922 mg
76. What is the percentage (based on weight) of Na in
Na2CO3?
a. 21.7%
b. 43.4%
c. 4.34%
d. 0.434%
77. How many milligrams of sodium chloride are there
in a 2 mmol solution? (MW of NaCl ¼ 58.5)
a. 117 mg
b. 11.7 mg
c. 1.17 mg

d. 1.17 g
78. How many millimoles of calcium fluoride are present
in 5 g? (MW of calcium fluoride ¼ 78)
a. 0.641 mmol
b. 6.41 mmol
c. 64.1 mmol
d. 64.1 mol
79. How many grams of KCl are needed to prepare
50 mmols solution? (MW of KCl ¼ 74.6)
a. 3730 mg
b. 37.30 mg
c. 3.730 g
d. 37.30 g
80. What is the percentage strength of 1:200 solution
of oil in alcohol?
a. 0.5% v/v
b. 0.005% v/v
c. 5% v/v
d. 0.5 mL


14

SECTION I

PHARMACEUTICAL PRACTICE

81. What is the percentage concentration of a 2:2000
solution of benzalkonium chloride?
a. 0.01% w/v

b. 1% w/v
c. 0.1% w/v
d. 10% w/v
82. To make 100 mL of 1:1000 w/v solution, how many
milligrams of NaHCO2 are needed?
a. 10 mg
b. 100 mg
c. 0.1 mg
d. 1 mg
83. If the reorder point for simvastatin 40 mg is 2 and
the maximum is 5, how many bottles should be
ordered if there is 1 bottle of simvastatin 40 mg?
a. 0
b. 1
c. 4
d. 5
84. You have a bottle of 1 g amoxicillin powder for
oral suspension. How many mL of purified water
are needed to prepare a 125 mg/5 mL suspension?
a. 10 mL
b. 1.0 mL
c. 40 mL
d. 4.0 mL
85. How much dilutant needs to be added to a 500 mg vial
of Merrem to obtain a concentration of 50 mg/mL?
a. 1 mL
b. 5 mL
c. 10 mL
d. 50 mL
e. 100 mL

86. A patient is to receive 1000 mL of solution over
8 hours. If the administration set delivers 20 gtt/mL,
at how many gtt/min should the solution be
infused?
a. 4 gtt/min
b. 20 gtt/min
c. 40 gtt/min
d. 0.4 gtt/min
87. A solution is to be administered by IV infusion at a
rate of 100 mL/hr. How many gtt/min should
be infused if the administration set delivers
20 drops/mL?
a. 5 gtt/min
b. 50 gtt/min
c. 3.3 gtt/min
d. 33 gtt/min
88. A patient is to receive 1 L of a normal saline by IV
infusion over 12 hours. What is the rate of infusion
expressed as gtt/min if the infusion set delivers 20
gtt/mL?
a. 28 gtt/min
b. 2.8 or 3 gtt/min

c.
d.

28 gtt/hr
280 gtt/hr

89. An IV infusion for a 22-lb child calls for 4 mcg/kg/min

at a rate of 1.2 mL/hr. How many milligrams of a drug
are required in a 100-mL infusion solution to supply
the required dose?
a. 440 mg
b. 200 mg
c. 3.3 mg
d. 20 mg
90. If 100 g dextrose is dissolved in 100-mL water to
make a final volume of 150 mL, what is the %w/v of
this solution?
a. 50% w/v
b. 66.7%w/v
c. 5% w/v
d. 6.67% w/v
91. What is the %w/v concentration of a 100 mL of
amoxicillin oral suspension containing 150 mg/5 mL?
a. 30% w/v
b. 1.5% w/v
c. 3% w/v
d. 15% w/v
92. If a patient has a temperature of 37 C, what is the
patient’s temperature in Fahrenheit?
a. 69 F
b. 100 F
c. 98 F
d. 98.6 F
93. If a solution has a ratio strength of 1:10000 w/v, what
is the % w/v of the solution?
a. 0.01% w/v
b. 1.0% w/v

c. 0.1% w/v
d. 10% w/v
94. The required dose for a 110-lb patient is 0.5 mg/kg/min.
If the concentration of the medication is 1 g/100 mL,
what is the infusion rate in mL/hr?
a. 2.5 mL/min
b. 25 mL/min
c. 150 mL/hr
d. 15.0 mL/hr
95. If 2.54 g of a drug is used to make 1000 tablets,
roughly how many milligrams will 60 tablets
contain?
a. 25 mg
b. 50 mg
c. 100 mg
d. 150 mg
e. 200 mg
96. What is the %w/w of 1000 mL solution when 200 g
dextrose is dissolved in 900 mL of water?
a. 18.2%
b. 20%


CHAPTER 2

c.
d.

1.82%
2.0%

97. A 16 oz. 10 g/15 mL lactulose bottle contains how
many tablespoon-doses?
a. 96 doses
b. 3.2 doses
c. 320 doses
d. 32 doses
98. If the required dose is 1 tsp bid, how long will an
180-mL bottle of clemastine fumerate syrup
0.5 mg/5 mL last?
a. 36 days
b. 18 days
c. 30 days
d. 60 days
99. How many milligrams of prochlorperazine are in a
5 mL injection containing 5 mg/mL?
a. 5 mg
b. 1 mg
c. 10 mg
d. 25 mg
100. The recommended daily adult dose of a medication
is 2 mg/kg body weight in 4 divided doses. What is
the daily dose for a person weighing 110 lb?
a. 100 mg daily
b. 25 mg daily
c. 220 mg daily
d. 10 mg daily
101. Kefzol is ordered at a dose of 30 mg/kg/day divided
three times daily for an elderly female patient who
weighs 88 lbs. How much Kefzol will be given to her

daily?
a. 400 mg
b. 800 mg
c. 1200 mg
d. 1.5 g
e. 1 g

Pharmaceutical Calculations

15

104. An IV bag with 1250 mL of IV fluids is to be infused
over 3 hours with a 15 gtt/mL set. How many
milliliters will be infused over each hour?
a. 300 mL/hr
b. 345 mL/hr
c. 416 mL/hr
d. 427 mL/hr
e. 458 mL/hr
105. A 240 lb male patient is prescribed zidovudine at a
dose of 2 mg/kg three times daily. How much
zidovudine will this patient receive daily?
a. 218 mg
b. 436 mg
c. 654 mg
d. 245 mg
e. 186 mg
106. A patient weighing 155 lbs is ordered dobutamine at
a rate of 5 mcg/kg/min. When the drug is admixed,
200 mg of dobutamine was put into a 500 mL bag of

normal saline (NS). What is the final concentration
of the solution in mcg/mL?
a. 5 mcg/mL
b. 40 mcg/mL
c. 200 mcg/mL
d. 400 mcg/mL
e. 444 mcg/mL
107. The required dose of Drug X for a 150-lb patient is
1 mg/kg/min. If the concentration of the medication
is 5 g/100 mL, what is the infusion rate in mL/hr?
a. 2.1 mL/min
b. 5 mL/min
c. 82 mL/hr
d. 400 mL/hr
108. What is the milliosmolarity of normal saline (0.9%
NaCl) solution? Na¼23, Cl¼35.5
a. 145 mOsm/L
b. 220 mOsm/L
c. 255 mOsm/L
d. 285 mOsm/L
e. 308 mOsm/L

102. How much Kefzol would have to be drawn up from
the vial and injected into an IV bag to make one dose
of Kefzol for the patient in question 101? The vial
you have on hand was compounded to a
concentration of 325 mg/mL.
a. 5.45 mL
b. 6.25 mL
c. 1.65 mL

d. 1.23 mL
e. 0.68 mL

109. If a solution contains 1 g of sodium chloride dissolved
in 100 mL of D5W, how many milliosmoles are
present? (Na ¼ 23; Cl ¼ 35.5; hydrous dextrose ¼ 198)
a. 60
b. 120
c. 240
d. 300
e. 360

103. A bag with 250 mL of NS will be infused over 2 hours
using a microdrip set (60 gtt/mL). What is the flow
rate in drops per minute?
a. 60 gtt/min
b. 100 gtt/min
c. 115 gtt/min
d. 125 gtt/min
e. 140 gtt/min

110. An order is received in the pharmacy for an irrigation
solution of 0.25% w/v acetic acid. The acetic acid in
stock is 99.9% w/w, and must be added to 128 oz of
purified water. How many grams of 99.9% w/w acetic
acid must be added to the purified water in order to
prepare the final irrigation solution?
a. 6.7
b. 8.2

16

SECTION I

c.
d.
e.

PHARMACEUTICAL PRACTICE

9.6
10.8
12.3

111. One gram of a given chemical is soluble in 10 mL of
alcohol. What is the specific gravity of alcohol if a
saturated solution is made with this chemical into
an 11.1% w/w solution?
a. 0.75
b. 0.8
c. 0.9
d. 1.0
e. 1.15
112. How many grams of iodine are consumed
daily from 0.3 mL tid of 5% w/v strong iodine
solution?
a. 450
b. 45
c. 4.5

d. 0.045
e. 0.0045
113. A technician is preparing a potassium chloride
infusion for a hypokalemic patient. The IV bag
contains 250 mL of normal saline and 5.86 g of KCl
(KCl molecular weight ¼ 74.6). In the final infusion
preparation, how many milliequivalents of
potassium chloride are present?
a. 12.7 mEq
b. 78.5 mEq
c. 43.7 mEq
d. 22.5 mEq
e. 36.4 mEq
114. What is the volume of distribution of a drug with
a clearance of 9 L/hr, F ¼ 50, and an elimination half
life of 7.8 hours?
a. 70 L
b. 93 L
c. 101 L
d. 149 L
115. How many mL of tetracycline suspension 250 mg/
5 mL must be given in order for the patient to
receive 150 mg?
a. 3 mL
b. 6 mL
c. 12 mL
d. 7.5 mL
e. 15 mL
116. An acidic drug has a pKa of 5.4. What percentage of
the drug is ionized in urine with a pH of 6.0?

a. 25.1%
b. 74.9%
c. 20.1%
d. 79.9%
117. A weakly basic drug has a pKa of 8.6. What percent
would be un-ionized in circulation?
a. 0.059%
b. 0.941%

c.
d.

5.9%
94.1%

118. A patient is to receive 2 mg/min of labetalol
hydrochloride that has been prepared by adding
200 mg of labetalol hydrochloride injection to 250 mL
of D5W to attain a final concentration of 2 mg/3 mL.
How many milliliters per hour should the nurse
infuse?
a. 2.5 mL/h
b. 150 mL/h
c. 3 mL/h
d. 180 mL/h
119. A patient is to receive 4 L of D5NS over 24 hours. If
the IV tubing has a drip factor of 15 gtt/mL, what is
the drip rate?
a. 18 gtt/min
b. 42 gtt/min

c. 55 gtt/min
d. 250 gtt/min
120. What is the day supply for this prescription?
Persantine 25 mg (quantity 100) SIG: 1 tab qod
a. 200
b. 100
c. 50
d. 25
e. 20
121. Which erythromycin salt(s) is/are available by
IV infusion?
I. Erythromycin lactobionate
II. Erythromycin stearate
III. Erythromycin ethylsuccinate
a.
b.
c.
d.
e.

I only
II only
I and II
I and III
II and III

122. The hydrogen ion concentration of a topical solution
is 1 Â 10À8. What is the pH of this solution?
a. 8
b. 4

c. 2
d. 6
e. None of the above
123. A 3-mEq/mL solution of KCl contains how many
milligrams per milliliter? (MW of KCl ¼ 74.5)
a. 0.04 mg/mL
b. 24.8 mg/mL
c. 111.8 mg/mL
d. 223.5 mg/mL
124. A patient is prescribed 10 mEq KCl once daily to
compensate for the potassium wasting effects of
furosemide. How many mg of KCl is in each dose?
(MW of KCl ¼ 74.5)
a. 3.73 mg
b. 7.45 mg