Pharmaceutical Calculations

Maria Glaucia Teixeira, Joel L. Zatz

• Publisher: Wiley
• Year: 2017
• Print ISBN: 9781118978511
• eBook ISBN: 9781118978535
• Edition: 5
• Topic: Medicine
• Subtopic: Pharmacology

Retaining the successful previous editions' programmed instructional format, this book improves and updates an authoritative textbook to keep pace with compounding trends and calculations – addressing real-world calculations pharmacists perform and allowing students to learn at their own pace through examples.

• Connects well with the current emphasis on self-paced and active learning in pharmacy schools
• Adds a new chapter dedicated to practical calculations used in contemporary compounding, new appendices, and solutions and answers for all problems
• Maintains value for teaching pharmacy students the principles while also serving as a reference for review by students in preparation for licensure exams
• Rearranges chapters and rewrites topics of the previous edition, making its content ideal to be used as the primary textbook in a typical dosage calculations course for any health care professional
• Reviews of the prior edition: "...a well-structured approach to the topic..." (Drug Development and Industrial Pharmacy) and "...a perfectly organized manual that serves as a expert guide..." (Electric Review)

Chapter 1
Review of Basic Mathematical Principles

Learning Objectives After completing this chapter the student should be able to:

1. Recall the skills of basic mathematical operations required to work in the health field.
2. Use estimation as a means of preventing errors.
3. Perform mathematical operations containing units.
4. Compare two quantities (ratio).
5. Apply ratio, proportion, and dimensional analysis in problem solving.

Pharmacists, nurses, doctors, and most health-related professionals perform basic calculations as a daily practice. While working in a variety of settings, pharmacists, for example, need to calculate doses and determine the number of dosage units required to fill prescriptions accurately, must determine the quantities of pharmaceutical ingredients required to compound formulas, and perform calculations related to dose adjustments for disease state management, and so on. The correct drug, strength, and amount of each medication prescribed that is dispensed in pharmacies must be finally checked by the pharmacist, who is legally accountable for an incorrect dose or dispensing of a wrong drug. The fact that most pharmaceuticals are prefabricated and not prepared inside the pharmacy does not lessen the pharmacist's responsibility.

Modern drugs are effective, potent, and therefore potentially toxic if not taken correctly. An overdose may be fatal. Knowing “how to” calculate the amount of each drug and “how to” combine them is not sufficient. Of course, dispensing a subpotent dose is not satisfactory either. The drug(s) given will probably not elicit the desired therapeutic effect and will therefore be of no benefit to the patient. Clearly, the only satisfactory approach is one that is completely free of error. Absolute accuracy is any health professional's goal. Since our goal when performing calculations is the correct answer, it is logical to suppose that any rational approach to a problem that results in the correct answer is acceptable. While this is true, some approaches are more coherent and practical than others. In this text we strive to use a method that requires as few steps as possible and that with which you will feel comfortable. Usually, the simplest, most direct pathway to the solution allows less opportunity for error in computation than does one that is more complicated.

In this chapter, we will review some techniques basic to all types of calculations. To he...

Table of contents

• Cover
• Title Page
• Copyright
• Dedication
• Preface
• Chapter 1: Review of Basic Mathematical Principles
• Chapter 2: Systems of Measurement
• Chapter 3: Prescriptions and Medication Orders
• Chapter 4: Weighing and Measuring in Pharmacy Practice
• Chapter 5: Dosage Calculations
• Chapter 6: Drug Concentration Expressions
• Chapter 7: Dilution and Concentration
• Chapter 8: Isotonicity
• Chapter 9: Dosage Calculations of Electrolytes
• Chapter 10: Calculations for Injectable Medications and Sterile Fluids
• Chapter 11: Enteral and Parenteral Nutrition
• Chapter 12: Miscellaneous Practical Calculations in Contemporary Compounding
• Appendices
• Literature Consulted
• Index
• End User License Agreement