NCLEX: Drug Dosage Calculation Exam 7

1. 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. 0.3 mL
2. 0.9 mL
3. 3 mL
4. 6 mL

2. 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?

1. 1.4 mL
2. 3.5 mL
3. 5 mL
4. 7.2 mL

3. 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?

1. 10 mL/hour
2. 5 mL/hour
3. 10.5 mL/hour
4. 1 mL/hour

4. 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?

1. 3.5 tablets
2. 3 tablets
3. 1.5 tablets
4. 1 tablet

5. Atropine 0.6 mg IM is ordered preoperatively. It is supplied as 0.4 mg/mL. How many milliliters should you administer?

1. 2.3 mL
2. 2 mL
3. 1.5 mL
4. 0.7 mL

6. 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?

1. 1 mL
2. 0.2 mL
3. 1.6 mL
4. 0.03 mL

7. 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?

1. 3.25 grams per day. Safe!
2. 3.9 grams per day. Safe!
3. 8.25 grams per day. Not safe!
4. 8.9 grams per day. Not safe!

8. Levothyroxine (Synthroid) 150 mcg 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 daily? A safe dose of Synthroid is 1.5 mcg/kg/day. The patient weighs 196 pounds. Is the dose safe?

1. 2 tablets. The patient is receiving 1.5 mcg/kg. Safe!
2. 1.5 tablets. The patient is receiving 1.5 mcg/kg. Safe!
3. 2 tablets. The patient is receiving 1.7 mcg/kg. Not safe!
4. 1.5 tablets. The patient is receiving 1.7 mcg/kg. Not safe!

9. 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?

1. 10 gtts/minute
2. 18 gtts/minute
3. 23 gtts/minute
4. 31 gtts/minute

10. 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?

1. 50 mL/hour
2. 100 mL/hour
3. 200 mL/hour
4. 300 mL/hour

Answers and Rationales

1. Answer: B. (1 mg/kg) x (0.3 mL/30 mg) x 200 lbs x (1 kg/2.2 lbs)= 0.9 mL
2. Answer: D. 180 mg x (5 mL/125 mg)=  7.2 mL
3. Answer: A. (1,000 units/ 1 hour) x (500 mL/ 50,000 units)=  10 mL/hour
4. Answer: C. 90 mg x (1 tablet/60 mg)= 1.5 tablets
5. Answer: C. 0.6 mg x (1 mL/0.4 mg)= 1.5 mL
6. Answer: B. 2 mg x (1 gr/60 mg) x [1 mL/(1/6 gr)]= 0.2 mL
7. Answer: B. *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/tablet) x (2 tablets/dose) x (6 doses/day) x (1 gram/1,000 mg)= 3.9 grams per day. Safe! *3.9 grams per day is less than the maximum safe dose of 4 grams, so it is safe.
8. Answer: C. 2 tablets. The patient is receiving 1.7 mcg/kg. Not safe!
   • 150 mcg x (1mg/1,000 mcg) x (1 tablet/0.075 mg) = 2 tablets
   • (150 mcg/ 196 lbs) x (2.2 lbs/1 kg ) = the patient is receiving 1.7 mcg/kg
   • *Not safe, the dose of 1.7 mg/kg is greater than 1.5 mg/kg, so the dose is too high
9. Answer: A. (250 mL/ 4 hrs) x (1 hr/60 mins) x (10 gtts/ mL)= 10 gtts/min
10. Answer: D. (100 mL/ 20 mins) x (1 hr/ 60 mins)= 300 mL/hour