RN101
Home of the Registered Nurses (RN) and
Licensed Practical Nurses (LPN)

 FORMULA: 

D/HXQ = Amount to give

D or desired dose: drug dose prescribed

H or have dose: drug dose available

Q or quantity: form and amount in which the drug comes

 

Example 1: 

Prescribed: 500 mg of Drug A

Dosage available: 250 mg of Drug A in 1 tablet

Calculate the amount of Drug A to administer

 

500 mg x 1 tab = 2 tablets of Drug A 

250 mg

 

Example 2: 

Prescribed: 80 mg of Drug B

Dosage available: 100 mg of Drug B in 2 ml

Calculate the amount of Drug B to administer

 

80 mg x 2 ml = 1.6 ml

100 mg

 

CONVERSION TABLE: 

1 liter (L)=1000 milliliters (ml)

1 ounce (oz)=30 milliliters (ml)

1 teaspoon (tsp)=5 milliliters (ml)

1 tablespoon (tbs)=15 milliliters (ml)

1 gram (g)=1000 milligrams (mg)

1 milligram (mg)=1000 micrograms (mcg)

1 grain (gr)=60 milligrams (mg)

1 kilogram (kg)=2.2 pounds (lb)

1/150 grain (gr)=0.4 milligrams (mg)

1/200 grain (gr)=0.3 milligrams (mg)

 

 

QUESTIONS:

 

1. The physician writes an order for secobarbital 0.2 g prn for sleep. Each secobarbital capsule is labeled 100 mg. The nurse should administer _______ capsule(s) per dose. 

 

2. The physician prescribed phenytoin 100 mg po each day. On hand are phenytoin capsules labeled 0.1 gram. The nurse should administer _______ capsule(s) per dose. 

 

3. The physician prescribed acyclovir 0.8 g po q4h. On hand are acyclovir tablets labeled 200 mg. The nurse should administer _______ tablet(s) for each dose. 

 

4. The physician prescribed alprazolam 1 mg po tid. On hand are 0.5 mg alprazolam tablets. The nurse should administer _______ tablet(s) per dose. 

 

5. The physician prescribed 600 mg of acyclovir po q4h. On hand are acyclovir tablets labeled 200 mg. The nurse should administer _______ tablet(s) per dose. 

 

 

6. The physician orders 0.2 mg of misoprostol. On hand are 200 mg misoprostol tablets. The nurse should administer _______ tablet(s) per dose. 

 

7.  The physician orders pemoline 37.5 mg po qAM. The pharmacy sends 18.75 pemoline tablets. The nurse should administer _______ tablet(s) per dose. 

 

8. The physician orders diltiazem hydrochloride SR gr 1 1/2 po bid. On hand are diltiazem SR labeled 90 mg per capsule. The nurse should administer _______ capsule(s) per dose.

 

9. The physician orders phenobarbital gr 1 2/3 po q12h. On hand are 100 mg phenobarbital tablets. The nurse should administer _______ tablet(s) per dose.

 

10. The physician orders calcitriol 0.5 micrograms po QD AM. The pharmacy sends 0.25 mcg calcitriol capsules. The nurse should administer _______ capsule(s) per dose. 

 

 

11. The physician orders nitroglycerin 0.3 mg sublingual STAT for chest pain. The dose may be repeated every 5 minutes x 3. On hand are 1/200 gr nitroglycerin tablets. The nurse should administer ______ tablet(s) per dose. 

 

12. The physician orders allopurinol 0.6 g po QD. On hand are 300 mg allopurinol tablets. The nurse should administer _______ tablet(s) per dose. 

 

13. The physician orders amoxicillin 250 mg q8h. On hand are 125 mg chewable amoxicillin tablets. The nurse should administer _______ tablet(s) per dose. 

 

14. The physician orders amoxicillin/potassium clavulanate 20 mg/kg/day po in 4 divided doses to a child weighing 66 lbs. The pharmacy sends 150 mg amoxicillin/potassium clavulanate tablets. The nurse should administer _______ tablet(s) per dose to the child. 

 

15. The physician orders ampicillin sodium 0.5 g po 4x daily. On hand are 500 mg ampicillin capsules. The nurse should administer _______ capsule(s) per dose. 

 

16. The physician orders 500 mg of amoxicillin by mouth to be administered every 6 hours. Available are 250 mg amoxicillin capsules. The nurse should administer _______ capsule(s) for each dose. The nurse will administer how many capsules per day? _______

 

17. The physician orders oxycodone 5 mg/acetaminophen (APAP) 325 mg combined tablets, one every 4 hours as needed for pain. The pharmacy has on hand 5 mg/APAP 325 mg oxycodone tablets. The nurse can administer a maximum of _______ tablets in a 24 hour period. 

 

18. The physician orders zidovudine 0.1 g every 4 hours. The pharmacy fills the prescription with 100 mg  zidovudine capsules. The home health nurse should instruct the client to take _______ capsule(s) every 4 hours totaling _______ capsule(s) per day. 

 

19. The physician orders vancomycin hydrochloride 2 g/day by mouth in 4 divided doses. The pharmacy fills the client's prescription with 500 mg vancomycin hydrochloride capsules. The nurse should instruct the client to take _______ capsule(s) per dose. 

 

20. The physician orders ursodiol 1 g po in 2 divided doses per day. The client weighs 220 lbs and the  safe dosage range is 8-10 mg/kg/day. The pharmacy fills the client's prescription with 500 mg ursodiol tablets. Is the ordered dose safe for this client? 

 

21. The physician orders trimethoprim 160 mg/sulfamethoxazole 800 mg po q12h. The pharmacy sends 80 mg trimethoprim/400 mg sulfamethoxazole tablets. The nurse should administer _______ tablet(s) per dose. 

 

22. The physician orders ursodiol 0.9 g po in 3 divided doses per day. The pharmacy fills the client's prescription with 300 mg ursodiol capsules. The nurse should instruct the client to take _______ capsule(s) per dose.

 

23. The physician orders pyridoxine 0.2 g po qd for a rifampin-induced B6 deficiency. The pharmacy supplies 50 mg pyridoxine tablets. The nurse should instruct the client to take _______ tablet(s) per dose.

 

24. The physician orders lithium carbonate 1.2 g po qd in 4 divided doses. The pharmacy supplies 300 mg lithium carbonate capsules. The nurse should instruct the client to take _______ tablet(s) per dose. 

 

25. The physician orders propylthiouracil 300 mg po qd in 4 divided doses. The pharmacy supplies 50 mg prophylthouracil tablets. The nurse shoul instruct the client to take _______ tablet(s) per dose.