1. Chapter 5
Unit, Percentage, Milliequivalent, Ratio, Household, and Apothecary Measures

2. International Units Measure drug’s action Not abbreviated
Not weight
Not abbreviated
Previously accepted abbreviation (U) on Joint Commission (JC) “Do Not Use” list

3. International Units
Written using Arabic numbers followed by space and word “unit”
Commas not used unless at least five digits
e.g., 6 units, 1000 units, 250,000 units

4. International Units Common medications expressed in units Insulin
Heparin

5. Percentage Measurements
Indicate parts per 100
Greater the percentage, stronger the solution

6. Percentage Measurements
Used primarily in intravenous (IV) solutions
Also used in topical, ophthalmic, and otic solutions
For skin, eyes, and ears

7. Percentage Measurements
In solutions, represent number of grams of drug per 100 mL of solution
e.g., 100 mL of 5% solution contains 5 g of drug
e.g., 100 mL of 0.9% solution contains 0.9 g of drug

8. Percentage Measurements
Dextrose and sodium chloride
Most common percentage dosages
Dextrose dosages written as whole number
e.g., 5% dextrose in water (D5W)
Sodium chloride dosages written as decimal fraction
e.g., 0.45% sodium chloride

9. Milliequivalent (mEq) Measurements
Expression of number of grams of drug in 1 mL of normal solution

10. mEq Dosages
Written using Arabic numbers followed by space and abbreviation mEq
Used in variety of oral and IV solutions
e.g., potassium chloride most commonly used
20 milliequivalents written as 20 mEq KCl

11. Percentage and mEq Measures
Solutions with combination of percentage and mEq measures
e.g., 5% dextrose in water with 0.45% sodium chloride and 20 milliequivalents of potassium chloride written as 20 mEq KCl in D 5%/0.45% NaCl

12. Ratio Measures Strengths primarily used to describe solutions
Written using Arabic numbers followed by space, colon, space, and another Arabic number

13. Ratio Measures
Ratio strengths represent parts of drug per parts of solution
Less solution drug is dissolved in, stronger the solution
Solution of 1 : 100 contains one part drug to 100 parts solution

14. Household Measures One of the oldest drug measurement systems
Volume measurements include ounce, tablespoon, teaspoon, dram, and drop
Volume of drop depends on size of dropper being used

15. Household Measures
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

16. Household/Metric Equivalents
Abbreviation
Metric
1 Ounce oz
30 mL
1 Tablespoon
tbsp
15 mL
1 Teaspoon
tsp
5 mL
1 Drop
gtt
1 mL

17. Apothecary Measures
Obsolete and should not be used