copyright 2015 cengage learning chapter 5 unit, percentage, milliequivalent, ratio, and household...

Copyright © 2015 Cengage Learning®

Chapter 5

Unit, Percentage, Milliequivalent, Ratio, and Household Measures

Copyright © 2015 Cengage Learning®Copyright © 2015 Cengage Learning®

International Units

• Measure drug’s action.– Not weight

• The word “units” is not abbreviated.• Previously accepted abbreviation (U) is now

on Joint Commission “Do Not Use” list.

(continues)

5-2


Warm Up

• P. 46, Problems 5.1

3


International Units (cont’d)

• Written using Arabic numbers followed by space and word “unit”.

• Commas not used unless at least five digits.• For example, 6 units, 1000 units, 250,000

units.

(continues)

5-4


International Units (cont’d)

• Common medications are expressed in units.– For example, insulin and heparin

5-5


Percentage Measurements

• Indicate parts per hundred• Greater the percentage, stronger the solution

(continues)

5-6


Percentage Measurements (cont’d)

• Used primarily in intravenous (IV) solutions• Also used in topical, ophthalmic, and optic

solutions– For skin, eyes, and ears

(continues)

5-7



• In solutions, represent number of grams of drug per 100 milliliters of solution.– For example, 100 mL of 5% solution contains 5 g of drug.– For example, 100 mL of a 2.5% solution contains 2.5 g of

drug.

(continues)

5-8



• Dextrose and sodium chloride– Most common percentage dosages– Dextrose dosages written as whole number

• For example, 5% dextrose in water (D5W)

– Sodium chloride dosages written as decimal fraction• For example, 0.45% sodium chloride

5-9


Milliequivalent (mEq) Measurements

• Expression of number of grams of drug in 1 mL of normal solution

5-10


mEq Dosages

• Written using Arabic numbers followed by space and abbreviation mEq

(continues)

5-11


mEq Dosages (cont’d)

• Used in variety of oral and IV solutions– For example, potassium chloride most commonly used

• 20 milliequivalents written as 20 mEq KCl

5-12


• Now do p. 48 Problems 5.2

13


Ratio Measures

• Strengths primarily used to describe solutions.

• Written using Arabic numbers followed by space, colon, space, and another Arabic number.

• Solution of 1:100 contains one part drug to 100 parts solution.

(continues)

5-14


Ratio Measures (cont’d)

• Represent parts of drug per parts of solution.• A solution that is 1 part drug in 2 parts solution

would be written 1:2.• The less solution a drug is dissolved in, the stronger the solution.

(continues)

5-15


Ratio Measures (cont’d)

• Ratio strengths are always expressed in their simplest terms.– For example, 2:10 would be incorrect.• It must be expressed as 1:5.

5-16


• Now do p. 48 Problems 5.3

17


Household Measures

• One of the oldest drug measurement systems• Volume measurements include ounce,

tablespoon, teaspoon, and drop

(continues)

5-18


Household Measures (cont’d)

• Drop is integral part of small volume medication preparation– Including those for eye, ear, and nose

• Drop used almost exclusively with medications with attached dropper

5-19


Household/Metric Equivalents

Household Abbreviation Metric1 Ounce oz 30 mL

1 Tablespoon tbsp 15 mL1 Teaspoon tsp 5 mL

1 Drop gtt 1 mL

5-20


Apothecary Measures

• Basically obsolete• Only measure still seen is grain (gr)

– Seldom used– Equivalent to 60 mg in metric system

5-21


Are you ready?

• Take the Summary Self Test p. 50• Take the on line chapter quiz. • How’d you do?

22

copyright 2015 cengage learning chapter 5 unit, percentage, milliequivalent, ratio, and household...

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