Extra Drug Calculations and Answers June2013 (1)

EXTRA DRUG CALCULATIONSPractice Problems

Answer the following questions by indicating whether you need less than 1 tab or more than 1 tab.

1. A client is to receive gr 1/300 of a medication. The tablets available are gr 1/150.

How many tablets do you need? ___________________________

2. A client is to receive 1.25 mg of a medication. The tablets available are 0.625 mg.




4. A client is to receive 10 mg of a medication. The tablets available are 20 mg.


5. A client is to receive 100 mg of a medication. The tablets available are 50 mg.


Solve the following problems using ratio and proportion. Express your answer in mL to the nearest tenth where indicated, and include the label on the answer.

6. Order: 7.5 mg p.o. of a medication.

Available: Tablets labeled 5 mg ___________________________

7. Order: gr 3/4 p.o. of a medication.

Available: Tablets labeled 30 mg ___________________________

8. Order: gr 1½ p.o. of a medication.

Available: Capsules labeled 100 mg ___________________________

9. Order: 0.25 mg IM of a medication.

Available: 0.5 mg per mL ___________________________

10. Order: 100 mg p.o. of a liquid medication.

Available: 125 mg per 5 mL ___________________________

11. Order: 20 mEq IV of a medication.

Available: 40 mEq per 10 mL ___________________________

12. Order: 5,000 units subcut of a medication.

Available: 10,000 units per mL ___________________________

13. Order: 50 mg IM of a medication.


14. Order: 0.5 g p.o. of an antibiotic.

Available: Capsules labeled 250 mg ___________________________




Available: 80 mg per mL ___________________________

17. Order: gr 1 IM of a medication.

Available: gr 1/2 per mL ___________________________

18. Order: gr xv of a medication.

Available: Tablets labeled gr v. ___________________________

19. Order: 0.24 g p.o. of a liquid medication.

Available: 80 mg per 7.5 mL ___________________________

20. Order: 20 g p.o. of a liquid medication.

Available: 10 g per 15 mL ___________________________


Available: 0.5 mg per 2 mL ___________________________


Available: 0.25 mg per mL ___________________________




Available: 7,500 units per mL ___________________________

25. Order: 0.45 mg p.o. of a medication.

Available: Tablets labeled 0.3 mg ___________________________



27. Order: 150 mg IV of a medication.



Available: 1.5 mg per 0.5 mL ___________________________

29. Order: 500 mcg IV of a medication.

Available: 750 mcg per 3 mL ___________________________


Available: 0.2 mg per 1.5 mL ___________________________


Available: 1,000 units per 1.5 mL ___________________________

32. Order: 0.6 g IV of a medication.

Available: 1 g per 3.6 mL ___________________________

33. Order: 3 g IV of a medication.

Available: 1.5 g per mL ___________________________



35. Order: 0.3 mg subcut of a medication.

Available: 1,000 mcg per 2 mL ___________________________


Available: 0.5 g per 2 mL ___________________________

37. Order: 10 mEq IV of a medication.

Available: 20 mEq per 10 mL ___________________________

38. Order: 165 mg IV of a medication.


39. Order: 35 mg subcut of a medication.



Available: 1,000 mg per 2.3 mL ___________________________

28. Order: Compazine 10 mg IM q4h p.r.n.

Available:

____________________

29. Order: AquaMEPHYTON 5 mg subcut every day for 3 days.

Available:

____________________

30. Order: Cogentin 1 mg IM stat.

Available:

____________________

31. Order: Valium (diazepam) 8 mg IM q4h p.r.n. for agitation.

Available:

____________________

32. Order: Sandostatin 0.05 mg subcut daily.

Available:

____________________

33. Order: Demerol 50 mg IM and Vistaril 25 mg IM q4h p.r.n. for pain.

Available: Demerol labeled 75 mg per mL

Vistaril labeled 50 mg per mL

____________________

34. Order: Reglan 5 mg IM b.i.d. ½ hour a.c.

Available:

____________________

35. Order: Heparin 5,000 units subcut b.i.d.

Available:

Express your answer in hundredths. __________________

____________________

36. Order: Morphine sulfate gr ¼ IM q4h p.r.n. for pain.

Available:

____________________

37. Order: Lasix (furosemide) 20 mg IM stat.

Available:

____________________

Using the label for ampicillin, answer the following questions.

1. What is the total dosage strength of ampicillin in this vial? _________________________________

2. How much diluent is added to the vial to prepare the medication for IM use? _________________________________

3. What diluent is recommended for reconstitution? _________________________________

4. What is the final concentration of the prepared solution for IM administration? _________________________________

5. How long will the reconstituted material retain its potency? _________________________________

6. 500 mg IM q6h is ordered. How many milliliters will you give? Shade the dosage in on the syringe provided. _________________________________

Using the label for Tazidime, answer the following questions.

7. What is the total dosage strength of Tazidime in the vial? ___________________________________

8. How much diluent is added to the vial to prepare the medication for IM use? ___________________________________

9. What diluent is recommended for reconstitution for IM administration? ___________________________________

10. What is the final concentration of the solution prepared for IM administration? ___________________________________

11. How long does the medication retain its potency at room temperature? _________________________________

12. How long does the medication retain its potency if it is refrigerated? ___________________________________

13. 400 mg IM q8h is ordered. How many milliliters will you give? Shade the dosage in on the syringe provided. ___________________________________

Using the label for Ticar, answer the following questions.

14. What is the total dosage strength of Ticar in the vial? ___________________________________

15. What diluent is recommended to prepare an IV dosage? ___________________________________

16. How many milliliters of diluent are needed to prepare an IM dosage? ___________________________________

17. What is the final concentration of the solution prepared for IM administration? ___________________________________

18. Ticar 500 mg IM q8h is ordered. How many milliliters will you give? Shade the dosage in on the syringe provided. ___________________________________

Using the label for Rocephin, answer the following questions.

19. What is the total dosage strength of Rocephin in this vial? ___________________________________

20. For what routes of administration is the medication indicated? ___________________________________

21. How much diluent must be added to the vial to prepare the medication for IV use?_______________________________

22. What kind of diluent is recommended for IV reconstitution? ___________________________________

23. What is the final concentration of the prepared solution for IV use? ___________________________________

24. How much diluent must be added to the vial to prepare the medication for IM use? _________________________________

25. What kind of diluent is recommended for IM reconstitution? ___________________________________

26. 1 g IV q12h is ordered. How many milliliters will you give? Shade the dosage in on the syringe provided. __________________________________

Using the label for Augmentin, answer the following questions.

27. How much diluent must be added to prepare the solution? ___________________________________

28. What type of solution is used for the diluent? ___________________________________

29. What is the final concentration of the prepared solution? ___________________________________

30. How should the medication be stored after it is reconstituted? ___________________________________

Using the label for Zovirax and a portion of the package insert, answer the following questions.

31. What is the total dosage strength of Zovirax in this vial? ___________________________________


33. What diluent is recommended for reconstitution? ___________________________________


35. What is the route of administration? ________________________

Using the label for erythromycin, answer the following questions.


37. What is the volume of the solution after it is mixed? ___________________________________


39. For how long is the reconstituted solution good? ___________________________________

Using the label for Zithromax, answer the following questions.

40. What is the total dosage strength of Zithromax in this vial? ___________________________________




44. What is the route of administration? ________________________

Using the label for cefazolin, answer the following questions.

45. What is the total dosage strength of cefazolin in this vial? ___________________________________

46. How many milliliters of diluent are needed to prepare an IM dosage? ___________________________________



49. How long does the medication maintain its potency at room temperature? ___________________________________

Using the label for fluconazole, answer the following questions.




53. How should the medication be stored after it is reconstituted? ___________________________________

CALCULATING FLOW RATES IN DROPS PER MINUTE

Points to Remember

• Knowing the drop factor is the FIRST step in accurate administration of IV fluids.

• The drop factor always appears on the package of the IV tubing.

• Macrodrops are large and deliver 10, 15, or 20 gtt/mL.

• Microdrops are small and deliver 60 gtt/mL.

• Drop factor = gtt/mL.

• Must be rounded to the nearest whole number.

Calculate the flow rate in gtt/min using the formula method or dimensional analysis.

12. Administer D5RL at 75 mL/hr. The drop factor is 10 gtt/mL.____________________

13. Administer D5 ½ NS at 30 mL/hr. The drop factor is a microdrop.____________________

14. Administer RL at 125 mL/hr. The drop factor is 15 gtt/mL.____________________

15. Administer 1,000 mL D5 0.33% NS in 6 hr. The drop factor is 15 gtt/mL.____________________

16. An IV medication in 60 mL of 0.9% NS is to be administered in 45 min. The drop factor is a microdrop.____________________

17. 1,000 mL of Ringer lactate solution (RL) is to infuse in 16 hr. The drop factor is 15 gtt/mL. ____________________

18. Infuse 150 mL of D5W in 2 hr. The drop factor is 20 gtt/mL.____________________

19. Administer 3,000 mL D5 and ½ NS in 24 hr. The drop factor is 10 gtt/mL.____________________

20. Infuse 2,000 mL D5W in 12 hr. The drop factor is 15 gtt/mL. ____________________

21. An IV medication in 60 mL D5W is to be administered in 30 minutes. The drop factor is a microdrop.____________________

Calculate the units of measure indicated by the problem.

1. Order: Infuse 1,000 units/hr of heparin from a solution of 1,000 mL 0.45% NS with 25,000 units of heparin. Calculate the rate in mL/hr.

________________________________

2. Order: Infuse D5 0.9% NS 1,000 mL with 25,000 units of heparin at 35 mL/hr. Calculate the dosage in units/hr.

________________________________

3. Order: Infuse 750 mL D5W with 30,000 units of heparin at 25 mL/hr. Calculate the dosage in units/hr.

________________________________

4. Order: Infuse D5W 1,000 mL with 25,000 units of heparin at 100 mL/hr. Determine the dosage in units/hr.

________________________________

5. A client weighs 176 lb. Heparin infusion 20,000 units in 1,000 mL 0.9% sodium chloride. Order: Bolus with heparin sodium at 80 units/kg, then initiate drip at 18 units/kg/hr. Calculate the following:

a. ______bolus dosage

b. ______infusion rate (initial)

c. ______mL/hr

THIS IS WHERE PEDIATRICS START:

22. A child weighs 35 lb and has an order for Keflex 150 mg p.o. q6h.

Available:

a. What is the recommended dosage in mg/kg/day? __________

b. What is the child's weight in kilograms to nearest tenth? __________

c. What is the safe dosage range for this child? __________

d. Is the dosage ordered safe? (Prove mathematically.) __________

e. How many milliliters will you administer for each dosage? __________

23. Refer to the label. The PDR indicates 15 mg/kg/day q8h of kanamycin as a safe dosage. Kanamycin 200 mg IV q8h is ordered for a child weighing 35 kg.

Available:

a. What is the safe dosage for this child for 24 hours? __________

b. What is the divided dosage? __________

c. Is the dosage ordered safe? (Prove mathematically.) __________

24. The recommended dosage of clindamycin oral suspension is 8 to 25 mg/kg/day in four divided dosages. A child weighs 40 kg.

a. What is the maximum dosage for this child in 24 hours? __________

b. What is the divided dosage range? __________

25. Phenobarbital 10 mg p.o. q12h is ordered for a child weighing 9 lb. The recommended maintenance dosage is 3 to 5 mg/kg/day q12h.

a. What is the child's weight in kilograms to the nearest tenth? __________

b. What is the safe dosage range

for this child? __________


d. Phenobarbital elixir is available in a dosage strength of 20 mg per 5 mL. What will you administer for one dosage? Calculate the dosage if it is safe. __________

26. Morphine sulfate 7.5 mg subcut q4h p.r.n. is ordered for a child weighing 84 lb. The recommended maximum dose for a child is 0.1 to 0.2 mg/kg/dose.

Available:


b. What is the safe dosage range for this child? __________


d. How many milliliters will you administer for one dosage? __________

27. The recommended dosage of Dilantin is 4 to 8 mg/kg/day q12h. Dilantin 15 mg p.o. q12h is ordered for a child weighing 11 lb.

Available:

a. What is the child's weight in kilograms? __________

b. What is the safe dosage range for this child? __________


d. How many milliliters will you administer for one dosage? __________

28. The recommended initial dosage of mercaptopurine is 2.5 mg/kg/day p.o. The child weighs 44 lb.


b. What is the initial safe daily dosage for this child? __________

29. For a child the recommended dosage of IV vancomycin is 40 mg/kg/day. Vancomycin 200 mg IV q6h is ordered for a child weighing 38 lb.


b. What is the safe dosage for this child in 24 hours? __________

c. What is the divided dosage? __________

d. Is the dosage ordered safe? (Prove mathematically.) __________

30. A 16-lb child has an order for amoxicillin 125 mg p.o. q8h.

a. What is the recommended dosage in mg/kg/day? __________

b. What is the child's weight in kilograms to the nearest tenth? __________

c. What is the safe range of dosage for this child in 24 hours? __________

d. Is the dosage ordered safe? __________

31. A 44-lb child has an order for Ilosone oral suspension 250 mg p.o. q6h. The usual dosage for children under 50 lb is 30 to 50 mg/kg/day in divided dosages q6h, and for children over 20 lb, 250 mg q6h.


b. What is the range of dosages safe for this child in 24 hours? __________


32. Refer to the Fungizone insert to calculate the dosage for an adult weighing 66.3 kg with good cardiorenal function. __________

33. A 200-lb adult is to be treated with Ticar for a complicated urinary tract infection. The recommended dosage is 150 to 200 mg/kg/day IV in divided dosages every 4 or 6 hours.

a. What is the adult's weight in kilograms to the nearest tenth? __________

b. What is the daily dosage range in grams for this client? __________

34. A child weighs 12 lb, 6 oz. The recommended dosage of V-Cillin oral solution for a child is 15 to 50 mg/kg/day in four divided doses.


b. What is the safe daily dosage range for this child? __________

ANSWERS TO PRACTICE PROBLEMS

Answers to Practice Problems

1. Less than 1 tab

2. More than 1 tab

3. Less than 1 tab

4. Less than 1 tab

5. More than 1 tab

6.

or

5 mg : 1 tab = 7.5 mg : x tab

x = 1.5 tabs or

tabs. 5 mg is less than

7.5 mg; therefore you will need more than

1 tab to administer the dosage.

7. Equivalent: 60 mg = gr 1 (gr

or

30 mg : 1 tab = 45 mg : x tab

x = 1.5 tabs or

tabs. 45 mg is more

than 30; therefore you need more than

1 tab to administer the dosage.

8. Equivalent: 60 mg = gr 1

or

100 mg : 1 cap = 90 mg : x cap

x = 1 cap. It would be impossible to administer 0.9 of a capsule. A 10% margin of difference is allowed between what is ordered and what is administered. When this 10% safety margin is used, no more than 110 mg and no less than 90 mg may be given.

The prescriber ordered gr

(90 mg). The capsules

available are 100 mg. Capsules are not divisible. Administering 1 cap is within the 10% margin of difference allowed.

9.

or

0.5 mg : 1 mL = 0.25 mg : x mL

x = 0.5 mL, 0.25 mg is less than 0.5 mg; you will need less than 1 mL to administer the dosage.

10.

or

125 mg : 5 mL = 100 mg : x mL

x = 4 mL. 100 mg is less than 125 mg; therefore you will need less than 5 mL to administer the dosage.

11.

40 mEq : 10 mL = 20 mEq : x mL

or

x = 5 mL. 20 mEq is less than 40 mEq; you will need less than 10 mL to administer the dosage.

12.

or

10,000 units : 1 mL = 5,000 units : x mL

x = 0.5 mL, 10,000 units is more than 5,000 units; therefore you will need less than 1 mL to administer the dosage.

13.

or

80 mg: 2 mL = 50 mg: x mL

x = 1.25 = 1.3 mL. 50 mg is less than 80 mg; therefore you will need less than 2 mL to administer the dosage.

14. Equivalent: 1,000 mg = 1 g (0.5 g = 500 mg)

or

x = 2 caps. 500 mg is more than 250 mg; therefore you will need more than 1 cap to administer the dosage.

15.

or

x = 16 mL. 400 mg is larger than 125 mg; therefore you will need more than 5 mL to administer the dosage.

16.

or


17.

or

x = 2 mL. gr½ is less than gr 1; therefore you will need more than 1 mL to administer the dosage.

18.

or

x = 3 tabs. gr 15 is more than gr 5; therefore you will need more than 1 tab to administer the dosage.

19. Equivalent: 1,000 mg = 1 g (0.24 g = 240 mg)

or

x = 22.5 mL. 240 mg is more than 80 mg; therefore you would need more than 7.5 mL to administer the dosage.

20.

or

x = 30 mL. 20 g is more than 10 g; therefore you would need more than 15 mL to administer the dosage.

21.

or

THIS STARTS PEDIATRICS ANSWERS

x = 0.5 mL, 0.125 mg is less than 0.5 mg; therefore you will need less than 2 mL to administer the dosage.

22.

or

x = 3 mL. 0.75 mg is more than 0.25 mg; therefore you will need more than 1 mL to administer the dosage.

23.

or

x = 15 mL. 375 mg is more than 125 mg; therefore you will need more than 5 mL to administer the dosage.

24.

or

x = 1.33 = 1.3 mL. 10,000 units is more than 7,500 units; therefore you will need more than 1 mL to administer the dosage.

25.

or

0.3 mg : 1 tab = 0.45 mg : x tab

x = 1.5 tabs or 1 ½ tabs. 0.45 mg is more

than 0.3 mg; therefore you will need more than 1 tab to administer the dosage.

NOTE

For questions 26-40 and Chapter Review Parts I and II, answers only are provided. Refer to setup for problems 1-25 if needed.

26. 1.2 mL

27. 1.9 mL

28. 0.7 mL

29. 2 mL

30. 1.1 mL

31. 1.7 mL

32. 2.2 mL

33. 2 mL

34. 2.2 mL

35. 0.6 mL

36. 0.8 mL

37. 5 mL

38. 3.3 mL

39. 0.9 mL

40. 1.6 mL

Answers to Chapter Review Part I

1. 1 tab

2. 1 cap

3. 2 tabs

4. 2 tabs

5. 2 tabs

6. 0.5 tab or

tab

7. 1 tab

8. 2 tabs

9. 1 tab

10. 1 tab

11. 2 caps

12. 1 tab

13. 2 caps

14. 2 caps

15. 2 tabs

16. 1 tab

17. 2 caps

18. 2 caps

19. 1 tab

20. 2 tabs

21. 0.5 tab or

tab

22. 1 tab

23. 2 caps

24. 2 caps

25. 1 cap

26. 3 tabs

27. 1 tab

28. 2 tabs

29. 1

tabs 1.5 tabs

30. 2 tabs

31. 3 tabs

32. 2 tabs

33. 2 tabs

34. 2 caps

35. 2 caps

36. 3 caps

37. 3 tabs

38. 1

tabs or 1.5 tabs

39. tab or 0.5 tab

40. 1 tab

Answers to Chapter Review Part II

41. 4 mL

42. 20 mL

43. 1.3 mL

44. 20 mL

45. 0.7 mL

46. 2.3 mL

47. 1 mL

48. 1 mL

49. 0.67 mL

50. 7.5 mL

51. 1 mL

52. 0.5 mL

53. 2 mL

54. 10 mL

55. 0.75 mL

56. 1.1 mL

57. 0.5 mL

58. 0.5 mL

59. 0.7 mL

60. 4 mL

61. 6 mL

62. 6.3 mL

63. 0.8 mL

64. 20 mL

65. 30 mL

66. 40 mL

67. 10 mL

68. 1 mL

69. 16.7 mL

70. 45 mL

71. 1.3 mL

72. 1.4 mL

73. 6.7 mL

74. 8 mL

75. 1.2 mL

76. 0.8 mL

77. 0.3 mL

78. 0.25 mL

79. 10 mL

80. 12.5 Ml

PAGES 615-619


1.

2.

3.

4.

5. 1.4 mL

6. 1 mL

7. 0.9 mL

8. 0.4 mL

9. 4.4 mL

10. 7 mL

11. 3.2 mL

12. a. 20 mL

b. 25 mg per mL; 500 mg per 20 mL is also correct.

c. 10 mL

13. a. 10 mL

b. 0.1 mg per mL

c. IV use only

14. a. 10 mL

b. 25 mg per mL

c. 2 mL

15. a. 20 mL

b. 100 mg per mL

c. 0.5 mL

16. a. 10 mL

b. 400 mcg per mL, 0.4 mg per mL

c. IM, subcut, IV

17. a. 20 mL

b. 2 mg per mL

c. 2

18. a. 2.5 mL

b. 10 mg per mL

19. a. 10 mL

b. 80 mg per mL

20. a. 200 mg per 100 mL, 2 mg per mL

b. IV infusion only

21. a. 10 mL

b. 10 mg per 10 mL, 1 mg per mL

22. a. 2.5 mL

b. 1 g per 2.5 mL, 400 mg per mL

c. IM use only

23. a. 20 mL

b. 2 mEq per mL

24. a. 50 mL

b. 1 mEq per mL

25. a. 10 mL

b. 1,000 units per mL

26. a. 10 mL

b. 100 units per mL

27. a. 2 mL

b. 10,000 units per mL, 20,000 units per 2 mL

28. 5 mg : 1 mL = 10 mg : x mL

or

Answer: 2 mL. The dosage ordered is more than the available strength; therefore you will need more than 1 mL to administer the dosage.

29. 10 mg : 1 mL = 5 mg : x mL

or

Answer: 0.5 mL. The dosage ordered is less than the available strength; therefore you will need less than 1 mL to administer the dosage. Answer stated as decimal (0.5 mL); mL is a metric measure.

30. 2 mg : 2 mL = 1 mg : x mL

or

Answer: 1 mL. The dosage ordered is less than the available strength; therefore you will need less than 2 mL to administer the dosage.

31. 5 mg : 1 mL = 8 mg : x mL

or

Answer: 1.6 mL. The dosage ordered is more than the available strength; therefore you will need more than 1 mL to administer the dosage.

32. Conversion is required. Equivalent: 1,000 mcg = 1 mg. Therefore 0.05 mg = 50 mcg.

100 mcg : 1 mL = 50 mcg : x mL

or

Answer: 0.5 mL. The dosage ordered is less than what is available. Therefore you will need less than 1 mL to administer the dosage. Milliliter (mL) is metric, and answer is expressed as decimal.

33. Demerol:

75 mg : 1 mL = 50 mg : x mL

or

Answer: 0.66 mL = 0.7 mL. The dosage ordered is less than the available strength. Therefore less than 1 mL would be required to administer the dosage.

Vistaril:

50 mg : 1 mL = 25 mg : x mL

or

Answer: 0.5 mL. The dosage ordered is less than the available strength. Therefore you will need less than 1 mL to administer the dosage. The total number of milliliters you will prepare to administer is 1.2 mL. This dosage is measurable on the small hypodermics. These two medications are often administered in the same syringe (0.7 mL Demerol + 0.5 mL Vistaril = 1.2 mL).

34. 5 mg : 1 mL = 5 mg : x mL

or

Answer: 1 mL. The dosage required is contained in 1 mL. Therefore you will need 1 mL to administer the dosage.

Alternate solution:

50 mg : 10 mL = 5 mg : x mL

or

This setup still gives an answer of 1 mL.

35. 20,000 units : 1 mL = 5,000 units : x mL

or

Answer: 0.25 mL. The dosage ordered is less than the available strength. Therefore you will need less than 1 mL to administer the dosage. This dosage can be measured accurately on the 1-mL (tuberculin) syringe, because it is measured in hundredths of a

milliliter. The dosage you are administering is 0.25 mL, which is .

36. Conversion is required. Equivalent: 60 mg = gr 1.

Therefore gr ¼ =15 mg.

15 mg : 1 mL = 15 mg : x mL

or

Answer: 1 mL. The label indicates that the dosage ordered is contained in 1 mL.

37. 10 mg : 1 mL = 20 mg : x mL

or

Answer: 2 mL. The dosage ordered is more than the available strength. Therefore you will need more than 1 mL to administer the required dosage (if dosage strength used is 10 mg per mL as indicated on the label).

Alternate solution:

40 mg : 4 mL = 20 mg : x mL

or


Answers to Critical Thinking Questions

a. The right medication. Hydroxyzine and hydralazine have similar names but are two different medications.

b. Not reading the medication labels carefully and comparing them with the order, or medication administration record (MAR).

c. Hydralazine is an antihypertensive and could cause a fatal drop in the client's blood pressure.

d. Carefully comparing the medication label and dosage with the order or MAR three times while preparing the medication. Perhaps if the nurse had consulted a reliable drug reference it may have alerted the nurse to the fact that hydralazine is used to treat hypertension and hydroxyzine is used for anxiety, which is what the medication was prescribed for.

Answers to Chapter Review

1. Conversion is required. Equivalent: 1,000 mg = 1 g.

Therefore 0.3 g = 300 mg.

150 mg : 1 mL = 300 mg : x mL

or

Answer: 2 mL. The dosage ordered is more than the dosage strength available; therefore you will need more than 1 mL to administer the dosage.

2. 0.1 mg : 1 mL = 0.2 mg : x mL

or

Alternate solution:

0.5 mg : 5 mL = 0.2 mg : x mL

or


Answer: 2 mL. The dosage ordered is more than the dosage strength available per mL; therefore you will need more than 1 mL to administer the dosage.

PAGES 633-635

44. 50 mcg : 1 mL = 60 mcg : x mL

or

Answer: 1.2 mL. The dosage ordered is greater than the available strength. You will need more than 1 mL to administer the dosage.

Alternate solution:

100 mcg : 2 mL = 60 mcg : x mL

or

This setup will still give an answer of 1.2 mL.

45. 20 mg : 1 mL = 10 mg : x mL

or

Answer: 0.5 mL. (Stated as 0.5 mL; mL is a metric measure.) The dosage ordered is less than the available strength. You will need less than 1 mL to administer the dosage.

46. 10 mg : 1 mL = 4 mg : x mL

or

Answer: 0.4 mL. The dosage ordered is less than the available strength. You will need less than 1 mL to administer the dosage.

47. 300 mcg : 1 mL = 175 mcg : x mL

or

Answer: 0.58 = 0.6 mL. The dosage ordered is less than the available strength. You will need less than 1 mL to administer the dosage.

Alternate solution:

480 mcg : 1.6 mL = 175 mcg : x mL

or

This setup would give the same answer of 0.58 mL = 0.6 mL.


1. 1 g per vial (1 gram per vial)

2. 3.5 mL

3. none stated

4. 250 mg per mL

5. 1 hr

6. 2 mL

7. 500 mg per vial

8. 1.5 mL

9. none stated (use an approved diluent)

10. 280 mg per mL

11. 24 hours (1 day)

12. 7 days (1 week)

13. 1.4 mL


15. sterile water for injection

16. 2 mL

17. 1 g per 2.6 mL

18. 1.3 mL


20. IM or IV (intravenous) use

21. 9.6 mL

22. IV diluent specified in the accompanying package insert

23. 100 mg per mL

24. 2.1 mL

25. 1% Lidocaine hydrochloride injection or sterile water for injection

26. 10 mL

27. 5 mL; 1 tsp

28. water

29. 125 mg per 5 mL

30. Refrigerate and keep tightly closed.

31. 1,000 mg (1 g) per vial

32. 20 mL


34. 50 mg per mL

35. IV infusion only

36. 140 mL

37. 200 mL

38. 200 mg per 5 mL

39. 10 days (refrigerated)

40. 500 mg per vial

41. 4.8 mL


43. 100 mg per mL

44. IV infusion only

45. 1 g per vial

46. 2.5 mL


48. 330 mg per mL

49. 24 hr

50. 24 mL

51. distilled water or purified water

52. 50 mg per 5 mL; 10 mg per mL

53. Store suspension at 5° to 25° C (41° to 77° F). Protect from freezing.

54. 20,000,000 units

55. 500,000 units per mL

56. 1,000,000 units per mL—This strength is closest to what is ordered.

57. 2 mL

58. 7 days (1 week)

59. 5,000,000 units


61. 1.4 mL

62. refrigerator

63. 7 days (1 week)


65. 7 days (1 week)

66. 1 g (1 gram) per vial

67. 3 mL


69. 280 mg per mL

70. 10 mL

71. 95 mg per mL

72.

73.

74. 300 mL qid = 300 mL × 4 = 1,200 mL

x = 800 mL of formula needed

1,200 mL − 800 mL = 400 mL (water)

Therefore you will add 400 mL of water to 800 mL of Sustacal to make 1,200 mL of ⅔-strength Sustacal.

75. 1 oz = 30 mL; therefore 16 oz = 480 mL

x = 12 oz (360 mL) of formula needed.

16 oz (480 mL) − 12 oz (360 mL) = 4 oz water (120 mL). You would need 360 mL of formula and 120 mL of water.

NOTE

For question using ounces, give answer in ounces.

76. 1 oz = 30 mL 20 oz = 600 mL

x = 300 mL; you need 10 oz of Ensure.

600 mL (20 oz) − 300 mL (10 oz) Ensure = 300 mL (10 oz of water)

Answer: 10 oz Ensure + 10 oz water = 20 oz ½-strength Ensure.

PAGES 642-643

9. 25 g dextrose : 1.125 g NaCl

Equivalent: 1 L = 1,000 mL

Therefore 0.5 L = 500 mL

Dextrose:

5 g : 100 mL = x g : 500 mL

or

NaCl:

or

10. 37.5 g dextrose : 3.375 g NaCl

Dextrose:

or

NaCl:

or


1.

2.

3.

4. Remember: When infusion time is less than an hour, use a ratio and proportion to determine the rate in mL/hr.

100 mL : 45 min = x mL:60 min

5.

6.

7. Remember: When infusion time is less than an hour, use a ratio and proportion to determine the rate in mL/hr.

30 mL : 20 min = x mL : 60 min

8. 10 gtt/mL, macrodrop

9. 60 gtt/mL, microdrop



12.

Answer: 13 gtt/min; 13 macrogtt/min

13.

14.


15. Step 1: Calculate mL/hr.

Step 2: Calculate gtt/min


16.

Answer: 80 gtt/min; 80 microgtt/min

NOTE

These problems could also be done by first determining rate in mL/min to be administered and then calculating rate in gtt/min or by using dimensional analysis.


Step 2: Calculate gtt/min.









21.

Answer: 120 gtt/min; 120 microgtt/min

NOTE

Practice problems could also have been done by first determining the rate in mL/min and then calculating the rate in gtt/min.

22. 20 gtt/mL

Answer: 3

23. 10 gtt/mL

Answer: 6

24.

Answer: 1

PAGES 654-655

75. Step 1:

Step 2: 60 × 0.25 = 15 min

6 hr and 15 min = infusion time

Step 3: (7:00 PM + 6 hr + 15 min)Answer: 1:15 AM; military time: 0115

76. a. 6 hr = infusion time

b. (3:10 AM + 6 hr = 9:10 AM). IV will be completed at 9:10 AM; military time: 0910.

77. Conversion is required. Equivalent:

1 L = 1,000 mL

Therefore 2.5 L = 2,500 mL

Step 1:

Step 2: 60 × 0.66 = 39.6 = 40 min

16 hr and 40 min = infusion time

78.

a. 10 mg : 1 mL = 120 mg : x mL

or

Answer: 12 mL. The dosage ordered is more than the available strength; therefore more than 1 mL would be required to administer the dosage ordered.

b. 40 mg : 1 min = 120 mg : x min

Answer: 3 min

79.

a. 100 mg : 20 mL = 60 mg : x mL

or

Answer: 12 mL. The dosage ordered is less than the available strength; therefore you will need less than 20 mL to administer the dosage ordered.

b.

80. x = 16.6 = 17 gtt/min


81.

Answer: 200 gtt/min; 200 microdrop/min


Answer: 25 mL/hr

83. 100 units : 500 mL = 20 units : x mL

Answer: 100 mL/hr

84. 100 units : 250 mL = 15 units : x mL

Answer: 38 mL/hr


1. 25,000 units : 1,000 mL = 1,000 units : x mL

or

Answer: 40 mL/hr. To infuse 1,000 units/hr from a solution of 25,000 units in D5 0.9% NS, the flow rate would be 40 mL/hr.

2. 25,000 units : 1,000 mL = x units : 35 mL

3. 30,000 units : 750 mL = x units : 25 mL

x = 1,000 units/hr

Answer: 1,000 units/hr

4. Calculate units/hr infusing.

1,000 mL : 25,000 units = 100 mL : x units

Answer: 2,500 units/hr

5. Convert the weight to kilograms.

Conversion factor: 2.2 lb = 1 kg

176 lb ÷ 2.2 = 80 kg

a. Calculate the heparin bolus dosage.

Answer: 6,400 units

b. Calculate the infusion rate for the IV drip (initial).

c. Determine the rate in mL/hr at which to set the infusion rate.

1,000 mL : 20,000 units = x mL : 1,440 units

Answer: 72 mL/hr

Answers to Critical Thinking Questions

a. The nurse used the incorrect concentration of heparin to prepare the IV solution. Heparin concentration of 100 units per mL is used for maintaining the patency of a line and for flushing.

b. The nurse should have read the label carefully because heparin comes in a variety of concentrations. Heparin IV flushes are available in 10 units per mL and 100 units per mL. Heparin for IV flush is never used interchangeably with heparin for injection.

Answers to Chapter Review


or

x = 0.35 mL. The dosage ordered is less than the available strength; therefore you will need less than 1 mL to administer the dosage.


or

Answer: 0.8 mL. The dosage ordered is less than the available strength; therefore you will need less than 1 mL to administer the dosage.


or



or


PAGES 668-669

39. a. 375 mcg/min

b. 22,500 mcg/hr

c. 23 mL/hr

Convert client's weight to kilograms

(2.2 lb = 1 kg).

165 1 b ÷ 2.2 = 75 kg

Calculate dosage per minute.

Convert mcg/min to mcg/hr.

Convert mcg/hr to mg/hr.

22, 500 mcg / hr = 22.5 mg / hr

Calculate flow rate.

250 mg : 250 mL = 22.5 mg : x mL

or

40. a. 5 mg : 1 mL = 125 mg : x mL

or

Answer: 25 mL. The dosage ordered is more than the available strength. Therefore you will need more than 5 mL to administer the dosage.

b.

41. Calculate the dosage per hour.

Convert grams to milligrams.

1, 000 mg = 1 g : 2 g = 2, 000 mg

Calculate mL/hr.


1. 6.8 kg

2. 30.9 kg

3. 14.1 kg

4. 23.6 kg

5. 32.3 kg

6. 60.5 kg

7. 3.8 kg

8. 2.6 kg

9. 46.9 lb

10. 38.9 lb

11. 48.4 lb

12. 33 lb

13. 74.8 lb

14. 157.1 lb

15. 160.6 lb

16. 216.3 lb

17. 4 kg

18. 1.5 kg

19. 2.9 kg

20. 3.6 kg

21. 1.9 kg

NOTE

Any of the methods presented in Chapter 25 can be used to calculate dosages; not all are shown in the Answer Key.

22. a. 25 to 50 mg/kg/day

b. Convert weight first (2.2 lb = 1 kg).

35 ÷ 2.2 = 15.9 kg

or

c. Dosage range is 397.5 to 795 mg/day.

d. The dosage ordered falls within the range that is safe (150 mg × 4 = 600 mg). 600 mg/day falls within the 397.5 to 795 mg/day range.

e. 125 mg : 5 mL = 150 mg : x mL

or

23. a.

525 mg—maximum dosage for 24 hr

or

b.

c. No, not safe. 200 mg × 3 = 600 mg/day. It also exceeds the dosage that should be given q8h. This is greater than the maximum dosage. Check order with the prescriber.

24. a.

or

or

Answer: 1,000 mg is maximum dosage.

b. four divided dosages

Answer: 80-250 mg/dose divided dosage range (250 mg/dose is maximum divided dosage)

25. a. Weight conversion

(2.2 lb = 1 kg)

9 ÷ 2.2 = 4.1 kg

b.

or

or

Safe dosage range for the child for a day is 12.3-20.5 mg/day

c. The dosage ordered is safe.

10 mg × 2 = 20 mg/day. The maximum dosage per day is 20.5 mg.

d. 20 mg : 5 mL = 10 mg : x mL

or

You need to give 2.5 mL to administer the ordered dosage of 10 mg.

26. a. Convert weight to kilograms

(2.2 lb = 1 kg).

84 1 b ÷ 2.2 = 38.2 kg

or

b. 3.8-7.6 mg/dosage

c. The dosage ordered is safe. 7.5 mg is less than 7.6 mg.

d. You would administer 0.5 mL.

15 mg : 1 mL = 7.5 mg : x mL

or

27. Convert weight to kilograms

(2.2 lb = 1 kg).

a. 11 1 b ÷ 2.2 = 5 kg

or

or

b. 20 to 40 mg/day

c. The dosage that is ordered is safe. It falls within the safe range. 15 mg × 2 = 30 mg/day.

d. 125 mg : 5 mL = 15 mg : x mL

or

You would administer 0.6 mL.

28. Convert the child's weight to kilograms

(2.2 lb = 1 kg).

a. 44 1 b ÷ 2.2 = 20 kg

or

b. 50 mg/day

29. a. Convert weight (2.2 lb = 1 kg).

38 1 b ÷ 2.2 = 17.3 kg

b.

or

c.

d. The dosage ordered is not safe. 200 mg × 4 = 800 mg/day. 800 mg is greater than 692 mg/day. It also exceeds the dose that should be given q6h. Check with prescriber.

30. a. 20-40 mg/kg/day

b. Convert weight (2.2 lb = 1 kg).

16 1 b ÷ 2.2 = 7.27 = 7.3 kg

or

or

c. Safe dosage range for the child is 146-292 mg/day.

d. The dosage ordered is not safe. 125 mg × 3 = 375 mg/day. 375 mg/day is greater than 146-292 mg/day; check with prescriber.

31. Convert weight (2.2 lb = 1 kg).

a. 44 1 b ÷ 2.2 = 20 kg

or

or

b. 600-1,000 mg/day

c. The dosage ordered is safe. 250 mg × 4 = 1,000 mg. 1,000 mg falls within the safe range.

32. No weight conversion is required.

or

Answer: 16.6 mg is the dosage for the adult.

33. Weight conversion is required (2.2 lb = 1 kg).

a. 200 1 b ÷ 2.2 = 90.9 kg

or

or

To determine the number of grams, convert the milligrams obtained to grams (1,000 mg = 1 g).

13, 635 mg ÷ 1, 000 = 13.63 g

(13.6 g to nearest tenth)

18, 180 mg ÷ 1, 000 = 18.18 g

(18.2 g to nearest tenth)

b. The daily dosage range in grams is 13.6-18.2 g/day.

34. Convert weight (2.2. lb = 1 kg, 16 oz = 1 lb).

6 oz ÷ 16 = 0.37 1 b = 0.4 1 b ( to nearest tenth )

Total weight in pounds = 12.4 lb

a. 12.4 1b ÷ 2.2 = 5.63 kg ( 5 .6 to nearest tenth )

or

or

b. The safe dosage range is 84-280 mg/day.

35. 0.6 m2

36. 0.78 m2

37. 0.9 m2

38. 0.8 m2

39. 0.28 m2

40. 0.44 m2

41. 0.8 m2

42. 0.28 m2

43. 0.52 m2

44. 0.45 m2

45. 0.9 m2

46. 0.3 m2

47. 0.58 m2

48. 0.51 m2

49. 0.68 m2

50. 0.18 m2 PAGES 680-682

REFERENCE

Morris, Gray. Calculate with Confidence, 5th Edition. Mosby, 2010.



Less than 1 tab




1. Order: Infuse 1,000 units/hr of heparin from a solution of 1,000 mL 0.45% NS with 25,000 units of heparin. Calculate the rate in mL/hr.

12. Administer D5RL at 75 mL/hr. The drop factor is 10 gtt/mL.____________________

Extra Drug Calculations and Answers June2013 (1)

Documents

Transcript of Extra Drug Calculations and Answers June2013 (1)