NCLEX: Drug Dosage Calculation Exam 5

1. Phenobarbital is supplied as 60 mg/mL. You need to administer 160 mg IV stat. How many milliliters should you administer?

1. 0.4 mL
2. 1.7 mL
3. 2 mL
4. 2.7 mL

2. 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?

1. 0.1 mL
2. 0.4 mL
3. 4 mL
4. 8 mL

3. 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?

1. 236 mg
2. 118 mg
3. 107.3 mg
4. 53.6 mg

4. 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?

1. 13 gtts/min
2. 21 gtts/min
3. 25 gtts/min
4. 33 gtts/min

5. 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?

1. 13 gtts/min
2. 17 gtts/min
3. 24 gtts/min
4. 38 gtts/min

6. 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?

1. 2 mL
2. 4 mL
3. 6 mL
4. 8 mL

7. You need to administer 40 mg of furosemide (Lasix) PO. You have on hand Lasix 20 mg tablets. How many tablets should you give?

1. 1 tablet
2. 2 tablets
3. 2.5 tablets
4. 4 tablets

8. You have an order for heparin 3000 units SC every 12 hours. You have available 5000 units/mL. How many milliliters will you give?

1. 1 mL
2. 0.2 mL
3. 0.6 mL
4. 1.2 mL

9. You need to administer 15 mg of morphine IM. You have on hand gr 1/4 per mL. How should you prepare the correct dose?

1. 1 mL
2. 2 mL
3. 4 mL
4. 7.5 mL

10. 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?

1. 2 tablets
2. 1 1/2 tablets
3. 1 tablet
4. 1/2 tablet

Answers and Rationales

1. Answer: D. 160 mg x (1mL/60 mg)=  2.7 mL
2. Answer: B. 4 mg x (1 gr/60mg) x [1mL/ (1/6 gr)]= 0.4 mL
3. Answer: D. (0.5 mg/kg) x 236 lbs x (1kg/2.2 lbs)= 53.6 mg
4. Answer: B. (500 mL/4 hrs) x (1 hr/60 mins) x (10 gtts/mL)= 21 gtts/min
5. Answer: B. (100mL/60 mins) x (10 gtts/mL)= 17 gtts/min
6. Answer: D. 80 mg x (2mL/20 mg)= 8 mL
7. Answer: B. 40 mg x (1 tablet/20 mg)= 2 tablets
8. Answer: C. 3,000 units x (1mL/5,000 units)= 0.6 mL
9. Answer: A. 15 mg x (1 gr/60 mg) x [1 mL/ (1/4gr)] =1 mL
10. Answer: D. 0.05 mg x (1,000 mcg/1 mg) x (1 tablet/100 mcg)= 1/2 tablet