T or F: Medical Math

Question 1

70 mg of phenobarbital equals 1 grain of phenobarbital

Answer 1

False
There are 64.8 mg in 1 grain

Question 2

100 kg is 220 lbs

Answer 2

True

Question 3

110 lbs is 50 kg

Answer 3

True

Question 4

10% Mannitol = 0.1gm/mL of Mannitol

Answer 4

True
Know that 10% = 10g/100mL = 0.1g/mL

Question 5

2.5 tsp = 12.5 mLs

Answer 5

True
1 tsp= 5 mLs
2.5 tsp x 5 = 12.5 mLs

Question 6

If a patient was ordered to receive 442.5 mg and the patient weighed 29.5 kg, the recommended dosage for the drug was 15 mg/kg.

Answer 6

True
442.5 mg/ 29.5 kg = 15 mg/kg

Question 7

If 565 mg of a drug with a concentration of 50 mg/mL was given to a patient, the patient should have received 11.3 mL of the drug

Answer 7

True
565 mg /50 mg/mL = 11.3 mL

Question 8

If an 18 lb dog needs 85 mg of Lasix 5%, the dog should receive 1.7 mLs of Lasix

Answer 8

True
Take the dose 85 mg and divide it by the concentration (5% = 5gm/mL = 50 mg/mL)
85 mg / 50mg/mL =1.7 mL

Question 8

If 2 1/2 tablets of a drug with the strength of 75 mg were given to a patient, the dosage the patient received was 187.5 mg.

Answer 8

True

Question 9

If a patient is to receive 0.5 mL/lb and the patient weighs 15 kg, the patient should receive 7.5 mLs of the drug

Answer 9

False
Take the recommended volume of 0.5mL/lb and multiply it by the weight (15kg x 2.2 = 33 lbs) so 0.5 mL/lb x 33 lbs =16.5 mL

Question 10

If 375 mg of a drug has been ordered, you will give 1 1/2 tablets with a 250 mg strength

Answer 10

375 mg / 250 mg/tab = 1.5 tablets

Question 11

If the tablets of a drug ordered contain 75 mg/tablet, and the patient is to receive 150 mg of the drug, should the patient receive 1/2 tablet of the drug

Answer 11

False

Question 11

150 mL of 40% Dextrose should be added to 600 mLs of LRS to make a 5% Dextrose solution

Answer 11

False
C1V1=C2V2
(40%)V1 = (5%)(600mL)
V1 = (5 x 600 mL) /40 =75mL

Question 12

The drug label reads 8%. The concentration of the drug in the bottle would be 80mg/mL.

Answer 12

True
8% x 10 = 80mg/mL

Question 13

If a patient needs 495 mg of a drug and the drug label reads 4% concentration, the volume of the drug to be given would be 5mL.

Answer 13

False
495 mg/ x mL = 40mg/ 1 mL
x mL = 12.4 mL

Question 14

If the dosage of lidocaine to be added to a patient’s IV fluid bag is 88ug of the drug and the concentration of lidocaine is 15ug/mL, you would add 5.9mLs of lidocaine to the IV fluid

Answer 14

False
880ug/ 15ug/mL=58.7mL

Question 14

80 mL of 50% dextrose should be added to 800 mL of LRS to prepare a 5% dextrose solution.

Answer 14

True
C1V1=C2V2
0.5xV1=0.05x800mL
V1=(0.05 x 800) / 0.5=80 mL

Question 15

150 mL of 40% Dextrose should be added to 600 mL of LRS to make a 5% Dextrose solution.

Answer 15

False

Question 16

If the tablets of a drug ordered contain 75 mg/ tablet, and the patient is to receive 50 mg of the drug, the patient should receive 1/2 tablet of the drug.

Answer 16

False

Question 17

If a 50 lb patient is to receive 1.8 mg/kg/hr of fentanyl, and there are 10 hours remaining in the IV fluid bag, the total dosage to be added to the IV bag would be 408.6 mg fentanyl

Answer 17

True

Question 17

If a patient is to be on 80 mL/hr of surgical fluids. The drip rate for this patient using a 15 gtt/mL drip set would be 3gtt/10 sec

Answer 17

True