# Chapter 04: Basic Math Review: Preparing for Medication Calculations(FREE) My Nursing Test Banks

**Chapter 04: Basic Math Review: Preparing for Medication Calculations**

**Test Bank**

**SHORT ANSWER**

**Dosage Calculations**

Calculate the following dosages.

1. What volume of Heparin is one dose?

Ordered: Heparin 12,000 units SC q12h

Available: Heparin 20,000 units/mL

ANS:

2. How many milliliters of KCl will you give?

Ordered: KCl 15 mEq PO BID

Available: 20% KCl labeled 40 mEq/15 mL

ANS:

3. What volume of aminophylline is one dose?

Ordered: aminophylline 175 mg IV q6h

Available: aminophylline ampule labeled 500 mg/20 mL

ANS:

4. What volume of PCN G constitutes one dose?

Ordered: PCN G 750,000 units IV q6h

Available: PCN G vial labeled 200,000 units/mL after reconstitution

ANS:

5. How many tablets of Synthroid will you give for one dose?

Ordered: Synthroid 0.1 mg PO every morning

Available: 50 mcg Synthroid tablets

ANS:

6. What volume of PCN G is in one dose?

Ordered: PCN G 1.25 mil units

Available: Multidose vial labeled 500,000 units/mL after reconstitution

ANS:

7. How many tablets of Zaroxolyn are in one dose?

Ordered: Zaroxolyn 0.005 gm PO q AM

Available: 2.5-mg tablets

ANS:

8. How much is one dose of Lanoxin?

Ordered: Lanoxin 375 mcg IV in the morning

Available: Lanoxin ampule labeled 0.5 mg/2 mL

ANS:

**IV Rate Practice Problems**

Calculations with conversion factors required. Round answers to the nearest tenth. Calculate IV rate in mL/hr for each problem.

9. 1 L D_{5}W to infuse in 8 hours

ANS:

10. 500 mL D_{5}LR to infuse in 4 hours

ANS:

11. 100 mL Protonix to infuse over 2 hours

ANS:

12. 0.45% NaCl 1000 mL over 6 hours

ANS:

13. 250 mL D_{10}W over 10 hours

ANS:

14. KCl 20 mEq in 150 mL D_{5}W to infuse over 2 hours

ANS:

15. Magnesium sulfate 5 gm in 100 mL D_{5}W to infuse over 3 hours

ANS:

16. 500 mL 0.9 normal saline to infuse over 2 hours

ANS:

17. 1000 mL 0.45 NS to infuse over 8 hours

ANS:

18. 250 mL vancomycin to infuse over 2 hours

ANS:

**Calculate IV rates in gtt/min.**

19. Give 1000 mL D_{5}NS q6h. Drop factor is 15 gtt/mL.

ANS:

20. Give 1 unit PRBC over 2 hours. Blood bag states approximate volume is 250 mL. Drop factor is 10 gtt/mL.

ANS:

21. Give D_{10}W 250 mL over 8 hours. Microdrip set delivers 60 gtt/mL.

ANS:

22. Infuse D_{5}W 1 L q12h. Drop factor is 20 gtt/mL.

ANS:

23. Administer 500 mL 0.45 NS over 4 hours. Drop factor is 10 gtt/min.

ANS:

24. Give 1500 mL 0.9 NS with 20 mEq K^{+} over 12 hours. Drop factor is 15 gtt/min.

ANS:

25. Infuse 1 L lactated Ringers over 10 hours. Drop factor is 25 gtt/ min.

ANS:

**Calculate small volumes to be infused in less than 1 hour in mL/hr.**

26. Kefzol 500 mg in NS 75 mL over 30 minutes

ANS:

27. Calcium gluconate 10% 16 mEq in 100 mL D_{5}W over 30 minutes

ANS:

28. Zantac 50 mg in NS 50 mL over 15 minutes

ANS:

29. Staphcillin 1 g in 100 mL D_{5}W over 45 minutes

ANS:

**Calculate small volumes to be infused in less than 1 hour in gtt/min.**

30. Ticar 500 mg IV q6h. Dilute in 75 mL D_{5}W and give over 45 minutes via Buretrol set with a drop factor of 60 gtt/mL.

ANS:

31. Piperacillin 2.5 gm IV q6h. Dilute in 100 mL D_{5}W and infuse over 30 minutes. Secondary set delivers 20 gtt/mL.

ANS:

32. Oxacillin 400 mg in 100 mL D_{5}W over 40 minutes. Secondary set delivers 15 gtt/mL.

ANS:

33. Tagamet 200 mg in D_{5}W 100 mL over 20 minutes. Drop factor is 15 gtt/mL.

ANS:

34. Ancef 250 mg IV piggyback diluted in 100 mL NS over 30 minutes. Drop factor is 10 gtt/min.

ANS:

**Calculate IV rates for medications administered over time. Set the rate in mL/hr. Round answers to the nearest tenth.**

35. Ordered: Morphine sulfate 10 mg/hr continuous IV

Available: MS 50 mg in 100 mL NS

ANS:

36. Aminophylline 250 mg in 500 mL. Infuse at 30 mg/hr.

ANS:

37. Pronestyl 4 g in 1000 mL D_{5}W. Infuse at 2 mg/min.

ANS:

38. Heparin 22,000 units in 500 mL NS at 800 units/hr.

ANS:

**Calculate IV rates for medications administered over time, based on body weight. Round answers to the nearest tenth. Set the rate in mL/hr.**

39. Ordered: Dobutrex 5 mcg/kg/min IV. Client weighs 145 lb.

Available: Dobutrex 250 mg in 250 mL D_{5}W

ANS:

40. Ordered: Infuse nitroprusside 100 mg in 500 mL D_{5}W at 3 mcg/kg/min. Patient weighs 55 kg.

ANS:

41. Ordered: Infuse amrinone 250 mg in 250 mL NS at 5 mcg/kg/min. Patient weighs 165 lb.

ANS:

42. Ordered: Dobutrex 6 mcg/kg/min. Bag is labeled D_{5}W 250 mL with 500 mg Dobutrex added. Patient weighs 198 lb.

ANS:

**Pediatric Practice Problems**

To determine whether dosages are appropriate, answer the following questions for each problem:

1. What is the appropriate low (therapeutic) to high (safe) range, in milligrams, for each dose of medication for this child?

2. What is the safe maximum dose for this child?

3. Is the prescribed dose therapeutic and/or safe?

a. If answer is yes, how much medication will be given for the ordered dose?

b. If answer is no, what will you do?

Round answers to the nearest tenth.

43. Ordered: Dilantin 40 mg PO BID

Pediatric dose range: 5 to 7 mg/kg/day

Childs weight: 6.7 kg

Available: Dilantin 30 mg/5 mL susp

ANS:

Low/Therapeutic Dose

High/Safe Dose

Dose range: 16.8 to 23.5 mg per dose

Ordered dose: 40 mg. This dose is higher than the pediatric dose range and is unsafe for this child.

Action: Call prescriber.

44. Ordered: Gantrisin 1.5 g PO QID

Pediatric dose range: 150 to 200 mg/kg/day

Childs weight: 30.4 kg

Available: Gantrisin 500-mg tablets

ANS:

Low/Therapeutic Dose

High/Safe Dose

Dose range: 1140 to 1520 mg

Ordered dose: 1.5 g = 1500 mg is within this range.

Calculate dose:

Action: Administer dose.

45. Ordered: Vistaril 10 mg IM q4-6h PRN nausea

Pediatric dose range: 0.5 to 1 mg/kg/dose

Childs weight: 44 lb

Available: Vistaril 25 mg/mL

ANS:

Low/Therapeutic Dose

High/Safe Dose

Dose range: 10 to 20 mg per dose

Ordered dose: 10 mg is within this range.

Calculate dose:

Action: Administer dose.

46. Ordered: Ibuprofen 40 mg PO q6h PRN temp higher than 101.8 F

Pediatric dose range: Child 6 mo to 12 yr, antipyretic: for temp lower than 102.5 F, 5 mg/kg/dose;

for temp higher than 102.5 F, 10 mg/kg/dose

May be given q6-8h: max daily dose of 40 mg/kg/day

Childs weight: 7-month-old weighs 18.5 lb; temp is 102.4 F.

Available: Ibuprofen susp. 80 mg/5 mL

ANS:

Only safe, maximum dose needs to be identified.

Ordered dose of 40 mg is safe. The dose does not exceed maximum dosage.

Calculate dose:

Action: Administer dose.

47. Ordered: Nebcin 10 mg IM q8h

Pediatric dose: 2.5 mg/kg/dose

Neonates weight: 4000 g

Available: Nebcin 40 mg/mL

ANS:

Ordered dose is safe.

Calculate dose:

Action: Administer dose.