Unit 9: Pharmacology Math Study Guide Answer Keys

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VOCABULARY REVIEW 1. Dispense: To prepare a drug for administration.

2. Stat: Immediately.

3. Unit dose: Method of preparing individual doses of medications by the pharmacy.

4. Nomogram: A graph on which variables are plotted so that a particular value can be read on the appropriate line.

5. Surface area: The total area of the body exposed to the outside environment.

6. Route: The method of administering a drug.

7. Numerator: The top number in a fraction.

8. Denominator: The bottom number in a fraction.

9. Proper fraction: A fraction in which the numerator is smaller than the denominator.

10. Improper fraction: A fraction in which the numerator is equal to or greater than the denominator; the numerator is so large that the fraction is equal to or greater than 1.

11. dosage

12. Strength

13. solute

14. solvent

SKILLS AND CONCEPTS 1. a. The brand name of the medication is Zithromax. b. The drug’s generic name is azithromycin. c. The manufacturer of the medication is Pfizer Labs. d. The manufacturer’s NDC code is 0069-3140-19. e. The lot number is 05-5015-32-1. f. The lot number is used to track the batch of medication. g. The specific storage requirements include store dry powder below 86° F and protect from

freezing; after mixing store at 41° F to 86° F. h. Identify any warnings or cautions on the label. Use within 10 days; discard after full dosing

completed; shake well before using. i. The total number of units of medication in the container is 30 mL. j. Each unit of medication contains a dosage strength of 5 mL. k. Look the drug up in a PDR. The typical pediatric dose of Zithromax is 10 mg/kg (maximum, 500

mg/dose) orally once a day for 3 days or 10 mg/kg (maximum, 500 mg/dose) orally as a single dose on the first day followed by 5 mg/kg (maximum, 250 mg/dose) orally once a day on days 2 through 5.

2. A proper fraction is one in which the numerator is smaller than the denominator. An improper fraction is one in which the numerator is equal to or greater than the denominator. Another way of looking at improper fractions is that the numerator is so large that the fraction is greater than or equal to 1. For example, the improper fraction 5/4 is greater than 1.

3. a. 2/3 proper b. 27/9 improper = 3 c. 14/7 improper = 2 d. 5/6 proper e. 15/5 improper = 3 f. 19/20 proper

Unit 9: Pharmacology Math Study Guide Answer Keys

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4. a. 15/20 = 3/4 b. 14/42 = 1/3 c. 120/180 = 2/3 d. 7/49 = 1/7 e. 12/16 = 3/4 f. 4/36 = 1/9

5. a. 2/3 × 9/8 = 18/24 = 3/4 b. 7/9 ÷ 3/4 = 28/27 = 1 1/27 c. 12/14 × 1/2 = 6/7 × 1/2 = 6/14 = 3/7 d. 5/12 ÷ 6/14 = 70/72 = 35/36

6. a. 1/3 = 0.33 b. 7/23 = 0.3 c. 16/84 = 0.19 d. 2/9 = 0.22 c. 26/34 = 0.76

7. a. 0.75 = 75% b. 0.33 = 33% c. 0.25 = 25% d. 1.0 = 100% e. 0.50 = 50% a. 0.45 = 45% b. 1.37 = 137% c. 0.97 = 97% d. 2.59 = 259% e. 0.62 = 62% f. 1.05 = 105%

8. a. 3:4 = x:12 4x = 36 x = 9 b. 1:2 = x:6 2x = 6 x = 3 c. 2:5 = x:100 5x = 200 x = 40 d. 2:6 = x:12 6x = 24 x = 4 e. 1:3 = x:75 3x = 75 x = 25 a. 5:4 = x:12 4x = 60 x = 15 b. 3:15 = x:25 15x = 75 x = 5 c. 4:28 = x:84 28x = 336 x = 12 d. 9:x = 5:250 5x = 2250 x = 450 e. 100:x = 10:50 10x = 5,000 x = 500

9. a. 1.28 mL = 1.3 mL b. 5.76 g = 5.8 g c. 14.74 mcg = 14.7 mcg d. 3.62 mL = 3.6 mL e. 0.18 mL = 0.2 mL f. 1.44 (unscored) tabs = 1 tab g. 2.11 cc = 2.1 cc h. 0.54 (scored) tab = 0.5 tab

10. a. Based on the type of system printed on the label, determine whether the physician’s order is in the same mathematic system of measurement. If the systems vary (e.g., the order is in teaspoons but the label states the medication is prepared in milliliters), accurately convert the order so that it matches the system used on the label.

b. Perform the calculation in equation form using the appropriate formula. c. Check the answer for accuracy and ask someone you trust to confirm your calculations.

Unit 9: Pharmacology Math Study Guide Answer Keys

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Part I: Metric System 1. 1/100 of a unit—centi-

2. 1/10 of a unit—deci-

3. 1/1,000 of a unit—milli-

4. 1/1,000,000 of a unit—micro-

5. 10 units—deca-

6. 100 units—hecto-

7. 1,000 units—kilo-

8. 1.5 L = 1,500 mL

9. 500 mg = 0.05 g

10. 3 g = 3,000 mg

11. 2,000 mg = 2 g

12. 2.5 g = 2,500 mg

13. 0.5 g = 500 mg

14. 500 mL = 0.5 L

15. 0.75 g = 750 mg

16. 1 kg = 1,000 g

17. 1,000 mg = 1 g

18. Refer to Table 34-2 in the textbook.

Part II: Apothecary System and Household Measurements 1. grain

2. minim

3. True

4. pound

5. True

6. a. ounce—oz b. teaspoon—tsp c. milligram—mg d. grain—gr e. pint—pt f. dram—dr g. tablespoon—Tbsp

7. 20; Divide 100 mg by 5 mL

8. 10

9. 6

10. 30

11. Refer to Table 34-5 in the textbook.

Unit 9: Pharmacology Math Study Guide Answer Keys

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Part III: Conversions Between Systems of Measurement 1. 150 lb = 68 kg

2. 78 lb = 35 kg

3. 18 kg = 39.6 lb

4. 210 lb = 95.5 kg

5. 71 kg = 156.2 lb

6. 198 lb = 90 kg

7. 112 lb = 51 kg

8. 163 lb = 74 kg

9. 21 kg = 46.2 lb

10. 4.4 lb = 2 kg

11. 6 lb 10 oz = 6.6 lb (16 oz/lb) = 3 kg

12. 62 inches = 155 cm

13. 34 inches = 85 cm

14. 97 inches = 242.5 cm

15. 5’ 0” = 60 inches = 150 cm

16. 6’ 2” = 74 inches = 185 cm

17. a. 30 gr = 30 gr × 1 g/15 gr = 30 g/15 = 2 g b. 0.25 gr = ¼ gr = 0.015 mg (conversion) c. 8 fl oz = 1 oz = 30 mL = 8 × 30 mL = 240 mL d. 12 mL = fl dr = (1 fl dr = 4 mL) = 12 mL × 1 fl dr/ 4 mL = 12 fl oz/4 = 3 fl dr e. 180 mg = (1 gr = 60 mg) = 180 mg × 1 gr/60 mg = 180 gr/60 = 3 gr f. 60 mg = 1 gr = 60 gr (conversion)

18. a. Physician’s order: Bicillin 400,000 units IM; Label: 1,200,000 units per 2 mL Answer: 1,200,000 units = 2 mL 1,200,000x = 800,000 mL x = 0.67 mL 400,000 units x b. Physician’s order: 75 mg Demerol IM stat; Label: 100 mg per cc Answer: 100 mg = 1 cc 100x = 75 cc x = 0.75 cc 75 mg x c. Physician’s order: 200 mcg Vitamin B12 SC; Label: 1,000 mcg per mL Answer: 1,000 mcg = 1 mL 1,000x = 200 mL x = 0.2 mL 200 mcg x d. Physician’s order: Amoxicillin solution 250 mg; Label: 0.5 g per 2 cc Answer: (250 mg = 0.25 g) 0.5 g = 2 cc 0.5x = 0.5 cc x = 1 cc 0.25 g x

19. a. Physician’s order: Compazine 12 mg IM. On hand is a 15 mL vial that contains 4 mg/mL. Answer: 12 mg × 1 mL 12/4 = 3 mL 4 mg

Unit 9: Pharmacology Math Study Guide Answer Keys

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b. Physician’s order: Depro-Medrol 25 mg IM. On hand is a 10 mL vial that contains 80 mg/mL. Answer: 25 mg × 1 mL 25/80 = 0.3 mL 80 mg c. Physician’s order: 250 mg Amoxil PO. On hand are 500 mg scored tablets. Answer: 250 mg × 1 tab 250/500 = 0.5 mL 500 mg d. Physician’s order: 15 mg Coumadin PO. On hand are 7.5 mg tablets. Answer: 15 mg × 1 tab 15/7.5 = 2 tabs 7.5 mg

CASE STUDIES Amount to Give Practice Charting 2 Keflex 500 mg cap administered po as ordered 2 Lasix 40 mg tab administered po as ordered 3 Zoloft 75 mg tab administered po as ordered 3 Claritin 30 mg tab administered po as ordered 4 Prilosec 40 mg cap administered po as ordered 1.5 Celebrex 200 mg cap administered po as ordered 0.5 Vioxx 12.5 mg tab administered po as ordered 0.5 Lanoxin 0.125 mg tab administered po as ordered 4 Coumadin 20 mg tab administered po as ordered 0.5 Augmentin 250 mg liquid administered as ordered 8 Prednisone 40 mg tab administered po as ordered 2 Prozac 20 mg cap administered po as ordered ½ Synthroid 0.44 mg tab administered po as ordered 3 Zocor 60 mg tab administered po as ordered 2 Glucophage 1 g tab administered po as ordered 2 Zestril 2.5 mg tab administered po as ordered 4 Norvasc 10 mg tab administered po as ordered 3 Cipro 750 mg tab administered po as ordered 4 Zyrtec syrup 4 mg liquid administered as ordered 2 Zovirax 200 mg tab administered po as ordered

Pediatric Dosages Amount to Give Penicillin 14,667 U Benadryl 4 mg Tylenol 180 mg Sudafed 15 mg West’s Nomogram Amount to Give Penicillin 29,412 units Benadryl 9 mg Tylenol 176 mg Sudafed 25 mg

Unit 9: Pharmacology Math Study Guide Answer Keys

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WORKPLACE APPLICATION OPTIONS 1. 19 kg, 19 mg

2. 9 mg

3. 330 mg

4. 106 mg

5. 0.5 mL

6. 0.5 mL

7. 148 mg

8. 2.5 mL

9. 0.5 mL