100 Dosage Calculation Practice and Answers

Calculations

Practice Problems

Note: A variety of types of problems are provided for practice. Not all situations will be encountered in all

states, depending on state limitations to LPN/LVN practice. Remember that you may need to help monitor

some medications, even if you don’t administer them.

1. You need to administer prochlorperazine (Compazine) 10 mg IM to a nauseated patient. You have

on hand Compazine 5 mg/mL. How should you prepare the correct dose?

2. An order reads furosemide (Lasix) 40 mg IV push. You have on hand 20 mg/2 mL. How should

you prepare the correct dose?

3. You need to administer 15 mg of morphine IM. It is supplied as gr 1/6 per mL. How should you

prepare the correct dose?

4. You have on hand diazepam (Valium) 5 mg/mL. You need to administer 8 mg IV push stat. to a

patient having a seizure. How much should you draw into the syringe?

5. A patient has an aminophylline IV drip ordered for acute asthma, to run at 20 mL/hour. No IV

infusion controller is available right now. How many drops per minute will be required if micro-

drip tubing is used?

6. A safe maintenance dose of aminophylline is 0.36 mg/kg/hour. It is supplied as 100 mg/100 mL.

Your patient is 130 pounds and is receiving 20 mL/hour. Is the dose safe?

7. Your patient is to receive metoprolol tartrate (Lopressor) 25 mg PO daily. The pharmacist dis-

penses 50 mg scored tablets. How many should your patient take each day?

8. A patient has an IV piggyback of ceftriaxone sodium (Rocephin) 500 mg in 50 mL D5W to run

over 20 minutes. The tubing has a drip factor of 10. How many drops per minute should be

administered?

9. A home care patient must restrict fluid intake to 2 L every 24 hours. He has only household

measuring cups. How many cups may he drink daily and not exceed the 2 L limit?

10. A patient has an IV piggyback of ceftriaxone sodium (Rocephin) 500 mg in 50 mL D5W to run

over 20 minutes. If you use an IV infusion controller, how many milliliters per hour will you set?

11. You are providing home care for a patient who needs 15 mL of magnesium hydroxide/aluminum

hydroxide (Maalox) PO. She has only standard measuring spoons in the house. How do you

instruct her to take her dose?

12. Your order reads penicillin 1.2 million units IM daily. You have penicillin 500,000 units/mL.

How should you prepare the correct dose?

13. Your order reads labetalol 40 mg IV push every 10 minutes until blood pressure is lower than

140/90 mm Hg. You have labetalol 5 mg/mL available. How should you prepare the correct dose?

14. You have on hand ergocalciferol liquid 8,000 units/2 mL. Your order reads ergocalciferol 225,000

units PO daily. How should you prepare the correct dose?

15. Your order reads ergocalciferol 225,000 units PO daily. You have on hand ergocalciferol in

50,000 unit tablets. How many do you administer?

16. Your order reads cortisone 15 mg PO every morning. You have on hand cortisone 10 mg tablets.


17. Your order reads ceftizoxime 1 g IV piggyback every 8 hours. The pharmacy supplies it in

100 mL D5W. You need to infuse it over 30 minutes. With a drop factor of 10, what drip rate

will you set?

18. Your order reads Zosyn 4.5 g in 100 mL D5W IV over 1 hour. You have microdrip tubing. What

drip rate will you set?

19. Your order reads levothyroxine 100 mg PO every morning. You have levothyroxine 0.05 mg

tablets. How many should you administer?

20. You have on hand morphine 500 mg in 500 mL normal saline. You need to administer morphine

80 mg/hour in a continuous IV infusion to a patient with terminal cancer pain. How many milli-

liters per hour will you set on the controller?

21. You have on hand enoxaparin (Lovenox) 30 mg/0.3 mL. You need to administer 1 mg/kgSC. Your

patient weighs 200 pounds. How much will you draw into a syringe?

22. Amoxil (amoxicillin) suspension 180 mg PO bid is ordered for a patient who cannot swallow

pills. It is supplied as 125 mg/5 mL. How many milliliters should you administer?

23. Heparin sodium, 1000 units/hour IV, is ordered for a patient with a blood clot in the leg. It is sup-

plied as 50,000 units in 500 mL of dextrose and water. How many milliliters per hour should be

set on the controller?

24. Diltiazem (Cardizem) 90 mg PO tid is ordered for a patient with hypertension. It is supplied in

60 mg scored tablets. How many tablets should you administer?

25. Atropine 0.6 mg IM is ordered preoperatively. It is supplied as 0.4 mg/mL. How many milliliters

should you administer?

26. Morphine sulfate 2 mg IV push is ordered to relieve shortness of breath in a patient with chronic

lung disease. It is supplied as gr 1/6 per mL. How many milliliters should you administer?

27. Each acetaminophen (Tylenol) #3 tablet has 325 mg of acetaminophen and 30 mg codeine. A

patient is told to take 2 tablets PO every 4 hours for pain. The maximum safe dose of acetamino-

phen is 4 g/day. The safe dose of codeine varies with tolerance. Is the dose safe?

28. Levothyroxine (Synthroid) 150 mg PO per day is ordered for a patient with hypothyroidism. It is

supplied as 0.075 mg tablets. How many tablets should the patient take? A safe dose of Synthroid

is 1.5 mg/kg/day. The patient weighs 196 pounds. Is the dose safe?

29. A patient is receiving 250 mL normal saline IV over 4 hours, using tubing with a drip factor of

10 drops/mL. How many drops per minute should be delivered?

30. Cephazolin 1 g IV is ordered three times a day for a patient with pneumonia. It is supplied in 100

mL dextrose and water, to run over 20 minutes. How many milliliters per hour should you set the

controller to deliver?

31. Your order reads ceftizoxime 1 g IV piggyback (IVPB) every 8 hours. The pharmacy supplies it

in 100 mL D5W. You need to infuse it over 30 minutes. Using gravity drip tubing with a drop

factor of 10, how fast will you run the piggyback?

32. You need to infuse 1000 mL of NS IV over 6 hours. How many milliliters per hour do you set on

the IV infusion controller?

33. You have an order for fosphenytoin (Cerebyx) 100 phenytoin equivalents (PE) IVPB qid. It

arrives in 50 mL of normal saline, with a note on the piggyback bag not to infuse faster than 150

PE/minute. How many milliliters per hour should you set on the controller?

34. You have 500 mL of lipids on a second IV infusion controller to piggyback into a primary hyper-

alimentation line. You want to run the infusion over 24 hours. At what rate should you run the

lipids?

35. You have an order for 500 mg vancomycin IVPB every 6 hours for a patient who weighs 120 lbs.

You know that you can safely administer up to 40 mg/kg/day. Is the order safe?

36. You have 350 mL packed red blood cells that you want to infuse IV over 2 hours. There is no

controller available. Your blood tubing delivers 10 gtts/mL. How many drops per minute should

you set?

37. You need to infuse corticotropin (Acthar) 25 U in 500 mL D5W IV over 8 hours. How many mil-

liliters per hour do you infuse on a controller?

38. A patient is taking acetaminophen (Tylenol) 325 mg, 2 tablets PO every 6 hours. How many

grams is the patient receiving in 24 hours?

39. You have an order for diphenhydramine hydrochloride (Benadryl) 40 mg IM ASAP. You have on

hand Benadryl 25 mg/mL. How many milliliters do you prepare?

40. You have digoxin (Lanoxin) 0.25 mg tablets, and you need to administer 0.375 mg PO. How

many tablets should you administer?

41. Phenobarbital is supplied as 60 mg/mL. You need to administer 160 mg IV stat. How many milli-

liters should you administer?

42. You have an order for morphine 4 mg IV push every 2 hours prn dyspnea. You have morphine gr

1/6 per mL on hand. How many milliliters should you prepare?

43. You need to administer amphotericin B 0.5 mg/kg IV daily to a patient with histoplasmosis who

weighs 236 pounds. How many milligrams should you expect to administer each day?

44. You have an order to infuse 500 mL normal saline IV over 4 hours. How many drops per minute

will you set on gravity tubing that delivers 10 gtts/mL?

45. A patient is to receive cefuroxime (Zinacef) 1 gin D5W 100 mL IV every 8 hours, to infuse over

60 minutes. How many drops per minute do you set on gravity tubing that delivers 10 gtts/mL?

46. You have an order for furosemide (Lasix) 80 mg IV every morning. You have on hand Lasix 20

mg in 2 mL sterile water. How many milliliters should you prepare?

47. You need to administer 40 mg of furosemide (Lasix) PO. You have on hand Lasix 20 mg tablets.

How many tablets should you give?

48. You have an order for heparin 3000 units SC every 12 hours. You have available 5,000 units/mL.

How many milliliters will you give?

49. You need to administer 15 mg of morphine IM. You have on hand gr 1/4

per mL. How should you


50. You have an order for levothyroxine (Synthroid) 0.05 mg PO. You have on hand Synthroid 100

mg tablets. How should you prepare the correct dose?

51. The recommended IV dose of gentamicin is 1 to 5 mg/kg. What is a safe range to administer to

an adult man weighing 190 pounds?

52. You are caring for a patient at home who must take magnesium hydroxide/aluminum hydroxide

(Maalox) 30 mL PO. How will you instruct the patient to measure the dose using ordinary house-

hold measuring devices?

53. You have an order to administer 1 L of Dextrose 5% in 0.45 normal saline IV over 16 hours.

How many milliliters per hour will you set on the IV infusion controller?

54. You have an order to administer 1 L of D5W IV over 8 hours. How many drops per minute will

you set if you are using tubing with a drop factor of 15?

55. Your order reads gatifloxacin (Tequin) 400 mg IV daily. It arrives in 50 mL of D5W, to run over

30 minutes. How many drops per minute will you set if you have tubing with a drop factor of 10?

56. You have an order to administer heparin sodium IV at 1000 units per hour. It is supplied by your

pharmacy as 25,000 units in 250 mL of D5W. For how many milliliters per hour should you pro-

gram the controller?

57. Your patient has an order for heparin SC 2500 units bid. You have on hand heparin 5000

units/mL. How many milliliters will you administer?

58. You evaluate a patient’s intake and output for 8 hours. Intake for 8 hours:

3 8-oz cups of coffee

4 oz orange juice3/

4cup of milk

8 oz tomato soup1/

2cup Jello

2 cups of water

750 mL of 0.9% normal saline IV

How many milliliters should you record as intake?

59. The physician orders codeine gr 1/4

IM every 4 hours prn for a patient with pain. You have on

hand codeine gr 1/2

per mL. What is the correct dose?

60. A patient is receiving 250,000 units of penicillin G IM every 6 hours. You have on hand 300,000

units/mL. How much will you draw into the syringe?

61. A patient has a primary IV of dextrose in water 1000 mL to be infused over 24 hours. What

would be the drip rate using tubing with a drop factor of 60?

62. A patient is sent home on captopril (Capoten), 6.25 mg PO bid. Her pharmacist dispenses 25 mg

scored tablets. How many should the patient take for each dose?

63. An IVPB of ranitidine (Zantac) 50 mg in 100 mL D5W is to run over 45 minutes. The tubing has

a drip factor of 15. How many drops per minute should you deliver?

64. You have an order for Phenobarbital 50 mg PO at bedtime. It is supplied as Phenobarbital elixir

20 mg/5 mL. How much will you administer?

65. You are providing home care for a patient who needs to mix her oral psyllium hydrophilic mucil-

loid (Metamucil) in 180 mL of water or juice. She has only standard measuring cups in the

house. How do you instruct her to take her dose?

66. You need to administer lorazepam (Ativan) 3 mg IM to an agitated patient. You have on hand 4

mg/mL. How much do you prepare?

67. You need to administer 125 mg of methylprednisolone sodium succinate (Solu-Medrol) IV push

bid to a patient with acute exacerbation of chronic obstructive pulmonary disease. You have on

hand 40 mg/mL. How much do you prepare?

68. A patient is to receive IV heparin now for a blood clot in the leg. It is ordered at 11 mL/hour.

Until the IV infusion controller is available. How many drops per minute will you run on micro-

drip tubing?

69. A patient has a bottle of warfarin (Coumadin) 5 mg tablets at home. After his most recent inter-

national normalized ratio (INR), the doctor calls and tells him to take 7.5 mg/day. How many

tables should the patient take?

70. You need to administer IV piperacillin sodium/tazobactam sodium (Zosyn) 3.375 g in 50 mL

D5W to run over 20 minutes. How many drops per minute do you set if the IV tubing has a drop

factor of 15?

71. Your patient is taking acetaminophen (Tylenol) gr 15 every 6 hours PO for headache pain. You

know the maximum safe dose is 4 g in 24 hours. Is the dose safe?

72. You are caring for your ill grandmother at home. She has an order for magnesium hydroxide/alu-

minum hydroxide (Maalox) 10 mL PO prn stomach upset. How do you instruct her to measure

her dose using household measuring spoons?

73. Your patient needs 2000 mL of saline IV over 4 hours for severely deficient fluid volume. How

many milliliters per hour will you set on a controller?

74. Your patient needs 2000 mL of D5W IV over 24 hours, to be delivered with a tubing set with a

drop factor of 15. How many drops per minute will you set for an infusion rate?

75. You have on hand penicillin 300,000 units/mL. Your order reads penicillin 1,000,000 units IM.

How will you fill the syringe?

76. The physician orders alprazolam (Xanax) 0.5 mg PO. You have on hand Xanax 0.25 mg tablets.

How many will you give?

77. You need to administer 250 mg of erythromycin PO. You have on hand 0.5 g tablets. How many

tablets will you give?

78. You need to administer 400 mg of erythromycin PO. You have on hand a suspension of 125 mg/5

mL. How much will you prepare?

79. You need to administer furosemide (Lasix) 2 mg/minute via continuous IV infusion on a con-

troller. Pharmacy has sent a bag of Lasix 400 mg diluted in D5W 250 mL. How many milliliters

per hour will you set on the controller?

80. A patient with HIV infection is receiving 200 mg of didanosine PO bid. The pharmacy only has

powder packets with 167 mg each, to be mixed with 4 oz of water. How many packets should the

patient mix? How much should the patient take? How can it be measured?

81. Your patient needs 12,000 units of heparinSC. You have on hand 5000 units/mL. How much will

you inject?

82. You have on hand atropine 0.4 mg/mL. You need to administer atropine gr 1/150 IM. How many

milliliters will you prepare?

83. The physician orders meperidine 75 mg IM every 4 to 6 hours prn for a patient admitted with

acute cholecystitis. You have on hand meperidine 50 mg/mL. How much will you give?

84. A patient is receiving 60 mg of methylprednisolone IM every 8 hours. You have on hand 75

mg/mL. How much will you draw up?

85. The physician orders an IV with heparin at 700 units/hour. You have a bag with 100 units/mL of

solution. How many milliliters per hour will you set on the infusion controller?

86. You have an IVPB of ranitidine (Zantac) 50 mg in 50 mL D5W to run over 30 minutes. The tub-

ing has a drip factor of 15. How many drops per minute will you set on the IV infusion controller?

87. Your patient has a headache but has difficulty swallowing pills. The physician orders acetamino-

phen 1000 mg PO every 4 to 6 hours prn. You have acetaminophen elixir 160 mg in 5 mL. How

much will you administer?

88. A patient with heart failure is on a 1000 mL fluid restriction each 24 hours. During the 7 a.m to

7 p.m. shift he has three meals, consuming 1/2

cup of coffee with each. He also has 50 mL of

water each time he takes his medications at 7 a.m., noon, and 5 p.m. Midafternoon, he drinks

240 mL of soda. How many milliliters may he consume during the 7 p.m. to 7 a.m. shift?

89. You are providing home care for a patient who needs to mix her oral potassium supplement with

120 mL of water or juice. She has only standard measuring cups in the house. How do you

instruct her to take her dose?

90. A patient is admitted to the emergency room with a fractured leg. The physician orders mor-

phine 15 mg IM stat. You have on hand morphine 10 mg/mL. How many milliliters will you

administer?

91. A patient is receiving 160 mg of methylprednisolone IM every 12 hours. You have on hand two

vials that each contains 125 mg/2 mL. How much will you draw into a syringe?

92. You have available lorazepam (Ativan) 0.5 mg tablets, and you need to administer 1 mg PO.

How many tablets will you administer?

93. A patient is instructed to take acetaminophen (Tylenol) liquid (elixir) 650 mg qid. The elixir is

160 mg/5 mL. How many milliliter per dose should the patient take?

94. The physician writes a “now” order for codeine 45 mg IM for a patient with a vertebral

compression fracture. You have on hand codeine 60 mg/2 mL. How many milliliters should

you give?

95. A patient with heart failure has a daily order for digoxin 0.25 mg PO. Digoxin 0.125 mg tablets

are available. How many tablets should you give?

96. A patient on hemodialysis must maintain careful intake and output. For breakfast he had 1

measured cup of coffee and 3 oz of milk on his cereal. For lunch he drank 6 oz of lemonade and

ate 1 cup of soup. For supper he drank 1 measured cup of coffee. He took his morning and

evening pills with 4 oz of water each time. Has he stayed within his 1000 mL fluid restriction?

97. You have on hand hydromorphone (Dilaudid) 4 mg/mL. You need to administer 0.015 mg/kg to

a patient who weighs 150 pounds. How many milliliters should you administer?

98. You have an order to administer 40 mg of methadone SC for opioid detoxification. You have on

hand 30 mg/mL. How much should you draw into the syringe?

99. A patient is placed on methadone maintenance therapy of 15 mg/day PO. It is supplied as 10

mg in 5 mL oral solution. How many milliliters should you instruct the patient to take?

100. A homebound patient must take 400,000 units of nystatin PO every 4 hours, to swish in the

mouth and then swallow. It is available as 100,000 units/5 mL. The patient has only household

measuring spoons. How should the patient be instructed to take the dose?

Calculations Practice

Problem Answers

1. You need to administer prochlorperazine (Compazine) 10 mg IM to a nauseated patient. You have on

hand Compazine 5 mg/mL. How should you prepare the correct dose?

10 mg 1 mL5 2 mL

5 mg

2. An order reads furosemide (Lasix) 40 mg IV push. You have on hand Lasix 20 mg/2 mL. How should

you prepare the correct dose?

40 mg 2 mL5 4 mL

20 mg

3. You need to administer 15 mg of morphine IM. It is supplied as gr 1/6 per mL. How should you


15 mg 1 gr 1 mL5 1.5 mL

60 mg 1/6 gr

4. You have on hand diazepam (Valium) 5 mg/mL. You need to administer 8 mg IV push stat. to a patient

having a seizure. How much should you draw into the syringe?

8 mg 1 mL5 1.6 mL

5 mg

5. A patient has an aminophylline IV drip ordered for acute asthma, to run at 20 mL/hour. No IV infusion

controller is available right now. How many drops per minute will be required if microdrip tubing is

used?

20 mL 1 hour 60 gtts5 20 gtts/min

1 hour 60 min mL

6. A safe maintenance dose of aminophylline is 0.36 mg/kg/hour. It is supplied as 100 mg/100 mL. Your

patient is 130 pounds and is receiving 20 mL/hour. Is the dose safe?

Because you have to compare a safe dose to the patient’s dose, you have to do two separate calcula-

tions:

0.36 mg 1 kg 130 pounds5 21.3 mg/hour is safe

kg 2.2 pounds

20 mL 100 mg5 patient is receiving 20 mg/hour; yes, dose is safe

Hour 100 mL

7. Your patient is to receive metoprolol tartrate (Lopressor) 25 mg/day PO. The pharmacist dispenses

50 mg scored tablets. How many tablets should your patient take each day?

25 mg 1 tab5 1/

2tab

50 mg

8. A patient has an IV piggyback of ceftriaxone (Rocephin) 500 mg in 50 mL D5W to run over

20 minutes. The tubing has a drip factor of 10. How many drops per minute should be administered?

50 mL 10 gtts5 25 gtts/min

20 min mL

9. A home care patient must restrict fluid intake to 2 L every 24 hours. He has only household measuring

cups. How many cups may he drink daily and not exceed the 2 L limit?

2 L 1000 mL 1 cup5 8.3 or 8 and 1/

3cups

1 L 240 mL

10. A patient has an IV piggyback of ceftriaxone (Rocephin) 500 mg in 50 mL D5W to run over

20 minutes. If you use an IV infusion controller, how many milliliters per hour will you set?

50 mL 60 min5 150 mL/hour

20 min 1 hour

11. You are providing home care for a patient who needs 15 mL of magnesium hydroxide/aluminum

hydroxide (Maalox) PO. She has only standard measuring spoons in the house. How do you instruct

her to take her dose?

15 mL 1 Tablespoon5 1 Tablespoon

15 mL

12. Your order reads penicillin 1.2 million units IM daily. You have penicillin 500,000 units/mL. How

should you prepare the correct dose?

1,200,000 units 1 mL5 2.4 mL

500,000 units

13. Your order reads labetalol 40 mg IV push every 10 minutes until blood pressure is lower than 140/90

mm Hg. You have labetalol 5 mg/mL available. How should you prepare the correct dose?

40 mg 1 mL5 8 mL

5 mg

14. You have on hand ergocalciferol liquid 8000 units/2 mL. Your order reads ergocalciferol 225,000 units

PO daily. How should you prepare the correct dose?

225,000 units 2 mL5 56 mL

8000 units

15. Your order reads ergocalciferol 225,000 units PO daily. You have on hand ergocalciferol in 50,000 unit

tablets. How many do you administer?

225,000 units 1 tablet5 4.5 tablets

50,000 units

16. Your order reads cortisone 15 mg PO every morning. You have on hand cortisone 10 mg tablets.


15 mg 1 tablet5 1.5 tablets

10 mg

17. Your order reads ceftizoxime 1 g IV piggyback every 8 hours. The pharmacy supplies it in 100 mL

D5W. You need to infuse it over 30 minutes. With a drop factor of 10, what drip rate will you set?


30 min mL

18. Your order reads Zosyn 4.5 g in 100 mL D5W IV over 1 hour. You have microdrip tubing. What drip

rate will you set?

100 mL 1 hour 60 gtts5 100 gtts/min

1 hour 60 min 1 mL

19. Your order reads levothyroxine 100 mg PO every morning. You have levothyroxine 0.05 mg tablets.

How many tablets should you administer?

100 mg 1 mg 1 tablet5 2 tablets

1000 mg 0.05 mg

20. You have on hand morphine 500 mg in 500 mL normal saline. You need to administer morphine 80

mg/hour in a continuous IV infusion to a patient with terminal cancer pain. How many milliliters per

hour will you set on the controller?

80 mg 500 mL5 80 mL/hour

hour 500 mg

21. You have on hand enoxaparin (Lovenox) 30 mg/0.3 mL. You need to administer 1 mg/kg SC. Your

patient weighs 200 pounds. How much will you draw into a syringe?

1 mg 0.3 mL 200 pounds 1 kg5 0.9 mL

kg 30 mg 2.2 pounds

22. Amoxil (amoxicillin) suspension 180 mg PO bid is ordered for a patient who cannot swallow pills. It

is supplied as 125 mg/5 mL. How many milliliters should you administer?

180 mg 5 mL5 7.2 mL

125 mg

23. Heparin sodium, 1000 units/hour IV, is ordered for a patient with a blood clot in the leg. It is supplied

as 50,000 units in 500 mL of dextrose and water. How many milliliters per hour should be set on the

controller?

1000 units 500 mL5 10 mL/hour

1 hour 50,000 units

24. Diltiazem (Cardizem) 90 mg PO tid is ordered for a patient with hypertension. It is supplied in 60 mg

scored tablets. How many tablets should you administer?

90 mg 1 tablet5 1.5 tablets

60 mg

25. Atropine 0.6 mg IM is ordered preoperatively. It is supplied as 0.4 mg/mL. How many milliliters


0.6 mg 1 mL5 1.5 mL

0.4 mg

26. Morphine sulfate 2 mg IV push is ordered to relieve shortness of breath in a patient with chronic lung

disease. It is supplied as gr 1/6 /mL. How many milliliters should you administer?

2 mg 1 gr 1 mL5 0.2 mL

60 mg 1/6 gr

27. Each acetaminophen (Tylenol) #3 tablet has 325 mg of acetaminophen and 30 mg codeine. A patient

is told to take 2 tablets PO every 4 hours for pain. The maximum safe dose of acetaminophen is

4 g/day. The safe dose of codeine varies with tolerance. Is the dose safe?

Because the safe dose of codeine is variable and is determined by patient response, you only need

to figure safe dose for the Tylenol for this problem.

325 mg 2 tablets 6 doses 1 gram 5 3.9 grams per day

tablet Dose day 1,000 mg

3.9 grams per day is less than the maximum safe dose of 4 grams, so it is safe.

28. Levothyroxine (Synthroid) 150 mg PO per day is ordered for a patient with hypothyroidism. It is sup-

plied as 0.075 mg tablets. How many tablets should the patient take daily? A safe dose of Synthroid

is 1.5 mg/kg/day. The patient weighs 196 pounds. Is the dose safe?

150 mg 1 mg 1 tablet5 2 tablets

1000 mg 0. 075 mg

150 mg 2.2 pounds5 the patient is receiving 1.7 mg/kg

196 pounds 1 kg

No, the dose of 1.7 mg/kg is greater than 1.5 mg/kg, so the dose is too high.

29. A patient is receiving 250 mL normal saline IV over 4 hours, using tubing with a drip factor of 10

drops/mL. How many drops per minute should be delivered?

250 mL 1 hour 10 gtts5 10 gtts/minute

4 hours 60 min mL

30. Cephazolin 1 g IV is ordered three times a day for a patient with pneumonia. It is supplied in 100 mL

dextrose and water, to run over 20 minutes. How many milliliters per hour should you set the con-

troller to deliver?

100 mL 60 min5 300 mL/hour

20 min hour

31. Your order reads ceftizoxime 1 g IV piggyback (IVPB) every 8 hours. The pharmacy supplies it in 100

mL D5W. You need to infuse it over 30 minutes. Using gravity drip tubing with a drop factor of 10,

how fast will you run the piggyback?


30 min mL

32. You need to infuse 1000 mL of normal saline IV over 6 hours. How many milliliters per hour do you

set on the IV infusion controller?

100 mL5 17 mL/hour

6 hours

33. You have an order for fosphenytoin (Cerebyx) 100 phenytoin equivalents (PE) IVPB qid. It arrives in

50 mL of normal saline, with a note on the piggyback bag not to infuse faster than 150 PE/minute.

How many milliliters per hour should you set on the controller?

150 PE 50 mL 60 minutes5 4500 mL/hour maximum rate

minute 100 PE 1 hour

Although 4500 mL/hour is the maximum rate, there is no reason to run it that fast; doing so could

damage the vein. Most piggybacks are infused over 20 to 30 minutes, or according to hospital policy.

50 mL infused over 30 minutes would be set at 100 mL/hour, which is well under the maximum rate.

34. You have 500 mL of lipids on a second IV infusion controller to piggyback into a primary hyperali-

mentation line. You want to run the infusion over 24 hours. At what rate should you run the lipids?

500 mL5 21 mL/hour

24 hours

35. You have an order for 500 mg vancomycin IVPB every 6 hours for a patient who weighs 120 lbs. You

know that you can safely administer up to 40 mg/kg/day. Is the order safe?

500 mg 4 doses 2.2 pounds5 patient is receiving 36.7 mg/kg/day

120 pounds day 1 kg

36.7 mg/kg is less than the safe dose of 40 mg/kg, so it is safe.

36. You have 350 mL packed red blood cells that you want to infuse IV over 2 hours. There is no con-

troller available. Your blood tubing delivers 10 gtts/mL. How many drops per minute should you set?


2 hours 60 minutes 1 mL

37. You need to infuse corticotropin (Acthar) 25 U in 500 mL D5W IV over 8 hours. How many milli-

liters per hour do you infuse on a controller?

500 mL5 63 mL/hour

8 hours

38. A patient is taking acetaminophen (Tylenol) 325 mg, 2 tablets PO every 6 hours. How many grams is

the patient receiving in 24 hours?

325 mg 2 tablets 4 doses 1 g5 2.6 g

tablet dose day 1000 mg

39. You have an order for diphenhydramine hydrochloride (Benadryl) 40 mg IM now. You have on hand

Benadryl 25 mg/mL. How many milliliters do you prepare?

40 mg 1 mL5 1.6 mL

25 mg

40. You have digoxin (Lanoxin) 0.25 mg tablets, and you need to administer 0.375 mg PO. How many

tablets should you administer?

0.375 mg 1 tablet5 1.5 tablets

0.25 mg

41. Phenobarbital is supplied as 60 mg/mL. You need to administer 160 mg IV stat. How many milliliters


160 mg 1 mL5 2.7 mL

60 mg

42. You have an order for morphine 4 mg IV push every 2 hours prn dyspnea. You have morphine gr 1/6

per mL on hand. How many milliliters should you prepare?

4 mg 1 gr 1 mL5 0.4 mL

60 mg 1/6 gr

43. You need to administer amphotericin B 0.5 mg/kg IV daily to a patient with histoplasmosis who

weighs 236 pounds. How many milligrams should you expect to administer each day?

0.5 mg 236 pounds 1 kg5 53.6 mg

kg 2.2 pounds

44. You have an order to infuse 500 mL normal saline IV over 4 hours. How many drops per minute will

you set on gravity tubing that delivers 10 gtts/mL?

500 mL 1 hour 10 gtts 5 21 drops/minute

4 hours 60 minutes mL

45. A patient is to receive cefuroxime (Zinacef) 1 g in D5W 100 mL IV every 8 hours, to infuse over 60

minutes. How many drops per minute do you set on gravity tubing that delivers 10 gtts/mL?

100 mL 10 gtts5 17 gtts/minute

60 minutes mL

46. You have an order for furosemide (Lasix) 80 mg IV every morning. You have on hand Lasix 20 mg in

2 mL sterile water. How many milliliters should you prepare?

80 mg 2 mL5 8 mL

20 mg

47. You need to administer 40 mg of furosemide (Lasix) PO. You have on hand Lasix 20 mg tablets. How

many tablets should you give?

40 mg 1 tablet5 2 tablets

20 mg

48. You have an order for heparin 3000 units SC every 12 hours. You have available 5000 units/mL. How

many milliliters will you give?

3000 units 1 mL5 0.6 mL

5000 units

49. You need to administer 15 mg of morphine IM. You have on hand gr 1/4

per mL. How should you pre-

pare the correct dose?

15 mg 1 gr 1 mL5 1 mL

60 mg 1/4

gr

50. You have an order for levothyroxine (Synthroid) 0.05 mg PO. You have on hand Synthroid 100 mg

tablets. How should you prepare the correct dose?

0.05 mg 1000 mg 1 tablet5

1/2

tablet1 mg 100 mg

51. The recommended IV dose of gentamicin is 1 to 5 mg/kg. What is a safe range to administer to an

adult man weighing 190 pounds?

1 mg 190 pounds 1 kg5 86 mg

1 kg 2.2 pounds

5 mg 190 pounds 1 kg5 431 mg

1 kg 2.2 pounds

The safe range is between 86 and 431 mg.

52. You are caring for a patient at home who must take magnesium hydroxide/aluminum hydroxide

(Maalox) 30 mL PO. How will you instruct the patient to measure the dose using ordinary household

measuring devices?

30 mL 1 Tbsp5 2 Tbsp

15 mL

53. You have an order to administer 1 L of 5% Dextrose in 0.45 normal saline IV over 16 hours.

How many milliliters per hour will you set on the IV infusion controller?

1 L 1000 mL5 63 mL/hour

16 hours 1 L

54. You have an order to administer 1 L of D5W IV over 8 hours. How many drops per minute will you

set if you are using tubing with a drop factor of 15?

1 L 1000 mL 1 hour 15 gtts5 31 drops/minute

8 hours 1 L 60 minutes mL

55. Your order reads gatifloxacin (Tequin) 400 mg IV daily. It arrives in 50 mL of D5W, to run over 30

minutes. How many drops per minute will you set if you have tubing with a drop factor of 10?


30 minutes mL

56. You have an order to administer heparin sodium IV at 1000 units per hour. It is supplied by your phar-

macy as 25,000 units in 250 mL of D5W. For how many milliliters per hour should you program the

controller?


hour 25,000 units

57. Your patient has an order for heparin SC 2500 units bid. You have on hand heparin 5000 units/mL.

How many milliliters will you administer?

2500 units 1 mL5 0.5 mL

5000 units

58. You evaluate a patient’s intake and output for 8 hours. Intake for 8 hours:

3 8-oz cups of coffee

4 oz orange juice3/

4cup of milk

8 oz tomato soup1/

2cup Jello

2 cups of water

750 mL of 0.9% normal saline IV

How many milliliters should you record as intake?

First, you must convert all amounts to the same units, usually milliliters.

3 cups 8 oz 30 mL5 720 mL coffee

1 cup 1 oz

4 oz 30 mL5 120 mL orange juice

1 oz

3/4

cup 240 mL5 180 mL milk

1 cup

8 oz 30 mL5 240 mL soup

1 oz

1/2

cup 240 mL5 120 mL Jello

1 cup

2 cups 240 mL5 480 mL water

1 cup

Now add: 720 1 120 1 180 1 240 1 120 1 480 1 750 5 2610 mL intake

59. The physician orders codeine gr 1/4

IM every 4 hours prn for a patient with pain. You have on hand

codeine gr 1/2

per mL. What is the correct dose?

1/4

gr 1 mL5 0.5 mL

1/2

gr

60. A patient is receiving 250,000 units of penicillin G IM every 6 hours. You have on hand 300,000

units/mL. How much will you draw into the syringe?

250,000 units 1 mL5 0.8 mL

300,000 units

61. A patient has a primary IV of dextrose in water 1000 mL to be infused over 24 hours. What would be

the drip rate using tubing with a drop factor of 60?

1000 mL 1 hour 60 gtts 5 42 gtts/minute


62. A patient is sent home on captopril (Capoten), 6.25 mg PO bid. Her pharmacist dispenses 25 mg

scored tablets. How many should the patient take for each dose?

6.25 mg 1 tablet5 1/

4tablet

25 mg

63. An IVPB of ranitidine hydrochloride (Zantac) 50 mg in 100 mL D5W is to run over 45 minutes.

The tubing has a drip factor of 15. How many drops per minute should you deliver?


45 minutes 1 mL

64. You have an order for phenobarbital 50 mg PO at bedtime. It is supplied as phenobarbital elixir 20

mg/5 mL. How much will you administer?

50 mg 5 mL5 12.5 mL

20 mg

65. You are providing home care for a patient who needs to mix her oral psyllium hydrophilic mucilloid

(Metamucil) in 180 mL of water or juice. She has only standard measuring cups in the house. How do

you instruct her to take her dose?

180 mL 1 cup5 0.75 or 3/

4cup

240 mL

66. You need to administer lorazepam (Ativan) 3 mg IM to an agitated patient. You have on hand 4

mg/mL. How much do you prepare?

3 mg 1 mL5 0.8 mL

4 mg

67. You need to administer 125 mg of methylprednisolone sodium succinate (Solu-Medrol) IV push

bid to a patient with acute exacerbation of chronic obstructive pulmonary disease. You have on

hand 40 mg/mL. How much do you prepare?

125 mg 1 mL5 3.1 mL

40 mg

68. A patient is to receive IV heparin now for a blood clot in the leg. It is ordered at 11 mL/hour. Until the

IV infusion controller is available. How many drops per minute will you run on microdrip tubing?


hour 60 minutes 1 mL

69. A patient has a bottle of warfarin (Coumadin) 5 mg tablets at home. After his most recent international

normalized ratio (INR), the doctor calls and tells him to take 7.5 mg/day. How many tables should the

patient take?

7.5 mg 1 tablet5 1.5 tablets

5 mg

70. You need to administer IV piperacillin sodium/tazobactam sodium (Zosyn) 3.375 g in 50 mL D5W to

run over 20 minutes. How many drops per minute do you set if the IV tubing has a drop factor of 15?


20 minutes 1 mL

71. Your patient is taking acetaminophen (Tylenol) gr 15 every 6 hours PO for headache pain. You know

the maximum safe dose is 4 g in 24 hours. Is the dose safe?

15 gr 4 doses 1 g5 4 g/day

dose Day 15 gr

The dose is at the upper limit of a safe dose.

72. You are caring for your ill grandmother at home. She has an order for magnesium hydroxide/

aluminum hydroxide (Maalox) 10 mL PO prn stomach upset. How do you instruct her to measure

her dose using household measuring spoons?

10 mL 1 teaspoon5 2 teaspoons

5 mL

73. Your patient needs 2000 mL of saline IV over 4 hours for severely deficient fluid volume. How many

milliliters per hour will you set on a controller?

2000 mL5 500 mL/hour

4 hours

74. Your patient needs 2000 mL of D5W IV over 24 hours, to be delivered with a tubing set with a drop

factor of 15. How many drops per minute will you set for an infusion rate?



75. You have on hand penicillin 300,000 units/mL. Your order reads penicillin 1,000,000 units IM.

How will you fill the syringe?

1,000,000 units 1 mL5 3.3 mL

300,000 units

76. The physician orders alprazolam (Xanax) 0.5 mg PO. You have on hand Xanax 0.25 mg tablets.

How many will you give?

0.5 mg 1 tablet5 2 tablets

0.25 mg

77. You need to administer 250 mg of erythromycin PO. You have on hand 0.5 g tablets. How many

tablets will you give?

250 mg 1 g 1 tablet5 1/

2tablet

1000 mg 0.5 g

78. You need to administer 400 mg of erythromycin PO. You have on hand a suspension of 125 mg/5 mL.

How much will you prepare?

400 mg 5 mL5 16 mL

125 mg

79. You need to administer furosemide (Lasix) 2 mg/minute via continuous IV infusion on a controller.

Pharmacy has sent a bag of Lasix 400 mg diluted in D5W 250 mL. How many milliliters per hour will

you set on the controller?

2 mg 250 mL 60 minutes5 75 mL/hour

Minute 400 mg 1 hour

80. A patient with HIV infection is receiving 200 mg of didanosine PO bid. The pharmacy only has pow-

der packets with 167 mg each, to be mixed with 4 oz of water. How many packets should the patient

mix? How much should the patient take? How can it be measured?

200 mg 4 oz5 4.8 oz

167 mg

The patient will have to mix two packets, each in 4 oz of water, and drink 4.8 oz measured in a cali-

brated measuring cup. If a cup that measures milliliters is available, then:

4.8 oz 30 mL 5 144 mL

1 oz

Or

144 mL 1 Tbsp5 9.6 Tbsp

15 mL

81. Your patient needs 12,000 units of heparin SC. You have on hand 5000 units/mL. How much will you

inject?

12,000 units 1 mL5 2.4 mL

5000 units

82. You have on hand atropine 0.4 mg/mL. You need to administer atropine gr 1/150 IM. How many milli-

liters will you prepare?

1/150 gr 60 mg 1 mL5 1 mL

1 gr 0.4 mg

83. The physician orders meperidine 75 mg IM every 4 to 6 hours prn for a patient admitted with acute

cholecystitis. You have on hand meperidine 50 mg/mL. How much will you give?

75 mg 1 mL5 1.5 mL

50 mg

84. A patient is receiving 60 mg of methylprednisolone IM every 8 hours. You have on hand 75 mg/mL.

How much will you draw up?

60 mg 1 mL5 0.8 mL

75 mg

85. The physician orders an IV with heparin at 700 units/hour. You have a bag with 100 units/mL of

solution. How many milliliters per hour will you set on the IV infusion controller?


1 hour 100 units

86. You have an IVPB of ranitidine (Zantac) 50 mg in 50 mL D5W to run over 30 minutes. The tubing

has a drip factor of 15. How many drops per minute will you set on the IV infusion controller?


30 minutes mL

87. Your patient has a headache but has difficulty swallowing pills. The physician orders acetaminophen

1000 mg PO every 4 to 6 hours prn. You have acetaminophen elixir 160 mg in 5 mL. How much will

you administer?

1000 mg 5 mL5 31.25 mL

160 mg

88. A hospitalized patient with heart failure is on a 1000 mL fluid restriction each 24 hours. During

the 7 a.m. to 7 p.m. shift he has three meals, consuming 1/2

cup of coffee with each. He also has 50

mL of water each time he takes his medications at 7 a.m., noon, and 5 p.m. Midafternoon, he drinks

240 mL of soda. How many milliliters may he consume during the 7 p.m. to 7 a.m. shift?

1/2

cup 240 mL5 120 mL coffee

1 cup

120 1 120 1 120 1 50 1 50 1 50 1 240 5 750

1000 mL – 750 mL 5 250 mL. He can drink 250 mL during the night shift.

89. You are providing home care for a patient who needs to mix her oral potassium supplement with 120

mL of water or juice. She has only standard measuring cups in the house. How do you instruct her to

take her dose?

120 mL 1 cup5 1/

2cup

240 mL

90. A patient is admitted to the emergency room with a fractured leg. The physician orders morphine

15 mg IM stat. You have on hand morphine 10 mg/mL. How many milliliters will you administer?

15 mg 1 mL5 1.5 mL

10 mg

91. A patient is receiving 160 mg of methylprednisolone IM every 12 hours. You have on hand two vials

that each contains 125 mg/2 mL. How much will you draw into a syringe?

160 mg 2 mL5 2.6 mL

125 mg

92. You have available lorazepam (Ativan) 0.5 mg tablets, and you need to administer 1 mg PO. How

many tablets will you administer?

1 mg 1 tablet5 2 tablets

0.5 mg

93. A patient is instructed to take acetaminophen (Tylenol) liquid (elixir) 650 mg qid. The elixir is 160

mg/5 mL. How many milliliters per dose should the patient take?

650 mg 5 mL5 20 mL

160 mg

94. The physician writes a “now” order for codeine 45 mg IM for a patient with a vertebral compression

fracture. You have on hand codeine 60 mg/2 mL. How many milliliters should you give?

45 mg 2 mL5 1.5 mL

60 mg

95. A patient with heart failure has a daily order for digoxin 0.25 mg PO. Digoxin 0.125 mg tablets are

available. How many tablets should you give?

0.25 mg 1 tablet5 2 tablets

0.125 mg

96. A patient on hemodialysis must maintain careful intake and output. For breakfast he had 1 cup of

coffee and 3 oz of milk on his cereal. For lunch he drank 6 oz of lemonade and ate 1 cup of soup.

For supper he drank 1 cup of coffee. He took his morning and evening pills with 4 oz of water each

time. Has he stayed within his 1000 mL fluid restriction?

First convert items to mL.

1 cup 240 mL5 240 mL

1 cup

3 oz 30 mL5 90 mL

1 oz

6 oz 30 mL5 180 mL

1 oz

4 oz 30 mL5 120 mL

1 oz

240 1 90 1 180 1 240 1 240 1 120 1 120 5 1230 mL

No, he has exceeded his fluid restriction limit by 230 mL.

97. You have on hand hydromorphone (Dilaudid) 4 mg/mL. You need to administer 0.015 mg/kg to a

patient who weighs 150 pounds. How many milliliters should you administer?

0.015 mg 1 kg 150 pounds 1 mL5 0.26 mL

1 kg 2.2 pounds 4 mg

98. You have an order to administer 40 mg of methadone SC for opioid detoxification. You have on hand

30 mg/mL. How much should you draw into the syringe?

40 mg 1 mL5 1.3 mL

30 mL

99. A patient is placed on methadone maintenance therapy of 15 mg/day PO. It is supplied as 10 mg in

5 mL oral solution. How many milliliters should you instruct the patient to take?

15 mg 5 mL5 7.5 mL

10 mg

100. A homebound patient must take 400,000 units of nystatin PO every 4 hours, to swish in the mouth

and then swallow. It is available as 100,000 units/5 mL. The patient has only household measuring

spoons. How should the patient be instructed to take the dose?

400,000 units 5 mL 1 teaspoon5 4 teaspoons

100,000 units 5 mL

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100 Dosage Calculation Practice and Answers