Copyright © 2015 Cengage Learning® Chapter 5 Unit, Percentage, Milliequivalent, Ratio, and Household Measures
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
Copyright © 2015 Cengage Learning® Warm Up P. 46, Problems 5.1 3
Copyright © 2015 Cengage Learning® 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
Copyright © 2015 Cengage Learning® International Units (cont’d) Common medications are expressed in units. –For example, insulin and heparin 5-5
Copyright © 2015 Cengage Learning® Percentage Measurements Indicate parts per hundred Greater the percentage, stronger the solution (continues) 5-6
Copyright © 2015 Cengage Learning® 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
Copyright © 2015 Cengage Learning® Percentage Measurements (cont’d) 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
Copyright © 2015 Cengage Learning® Percentage Measurements (cont’d) 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
Copyright © 2015 Cengage Learning® Milliequivalent (mEq) Measurements Expression of number of grams of drug in 1 mL of normal solution 5-10
Copyright © 2015 Cengage Learning® mEq Dosages Written using Arabic numbers followed by space and abbreviation mEq (continues) 5-11
Copyright © 2015 Cengage Learning® 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
Copyright © 2015 Cengage Learning® Now do p. 48 Problems
Copyright © 2015 Cengage Learning® 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
Copyright © 2015 Cengage Learning® 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
Copyright © 2015 Cengage Learning® 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:
Copyright © 2015 Cengage Learning® Now do p. 48 Problems
Copyright © 2015 Cengage Learning® Household Measures One of the oldest drug measurement systems Volume measurements include ounce, tablespoon, teaspoon, and drop (continues) 5-18
Copyright © 2015 Cengage Learning® 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
Copyright © 2015 Cengage Learning® Household/Metric Equivalents HouseholdAbbreviationMetric 1 Ounceoz30 mL 1 Tablespoontbsp15 mL 1 Teaspoontsp5 mL 1 Dropgtt1 mL 5-20
Copyright © 2015 Cengage Learning® Apothecary Measures Basically obsolete Only measure still seen is grain (gr) –Seldom used –Equivalent to 60 mg in metric system 5-21
Copyright © 2015 Cengage Learning® Are you ready? Take the Summary Self Test p. 50 Take the on line chapter quiz. How’d you do? 22