*Calculations

Question 1

What is the formula for mmols?

Answer 1

Mmols = mg/MW

Question 2

Diltiazem 100mg/ml drip Sig 10 mg/hr

At what rate (ml/hr) should the diltiazem drip be set to provide the prescribed dose?

Answer 2

10 mg/hr x 100ml/100 mg = 10 ml/hr

*Use dimensional analysis here

Question 3

10/22/15. D51/2 NS 50mL/hr

Premixed bags of D51/2 NS (1 liter) are available on the floor. The patient’s infusion is started at 1300 the day it was ordered. On what day and time will the pre-mixed bag run out?

Answer 3

50mL/1 hr x 1000ml/x hr = 20 hrs

Answer: 10/23 at 0900

Question 4

How many mL is in a tsp (t)?

Answer 4

5 mL

Question 5

How many mL is in a tbsp (T)?

Answer 5

15 mL

Question 6

How many mL are in 1 ounce (oz)?

Answer 6

30mL

Question 7

How many cm are in 1 inch?

Answer 7

2.54 cm

Question 8

How many mg are in a grain (gr)?

Answer 8

65 mg

Question 9

What is the definition of kilo?

Answer 9

1,000, as in kg

Question 10

What is the definition of deci?

Answer 10

1/10, as in dL

Question 11

What is the definition of milli?

Answer 11

1/1,000, as in mL

Question 12

What is the definition of micro?

Answer 12

1/1,000,000 as in mcg

Question 13

What is the definition of nano?

Answer 13

1/1,000,000,000 as in ng

Question 14

If 200 capsules contain 500 mg of an active ingredient, how many milligrams of the active ingredient of 76 capsules contain?

Answer 14

200 caps/ 500mg = 76 caps/ x mg

Answer: 190 mg

Question 15

If one 10ml vial contains 0.05 g of diltiazem, how many milliliters should be administered to provide a 25 mg dose of diltiazem?

Answer 15

Milli = 1/1000

0.05g x 1,000 mg = 50 mg

Now calculate the number of mL for a 25 mg dose

50mg/10mL = 25mg/ x mL

Answer: 5 mL

Question 16

How many ounces AND mL are in one pint?

Answer 16

16 ounces and 473 mL

Question 17

His phenobarbital elixir contains 18.2 mg of phenobarbital per five ML, how many grams of phenobarbital would be used in preparing a pint of the elixir? Round to the nearest 10th.

Answer 17

First convert milligrams to grams

18. 2mg/x g = 1000mg/1g. 0.0182g
19. 0182g/ 5 mL = x g/ 473 mL

Answer: 1.7 g

Question 18

Digoxin injection is supplied in ampules of 500 µg (mcg) per 2 mL. How many milliliters Musta nurse administer to provide a dose of open. 2 mg? Round to the nearest 10th.

Answer 18

First convert 500 µg to milligrams

500mcg x 1mg/1,000mcg = 0.5 mg

0.5mg/2 mL = 0.2mg /x mL. X= 0.8mL

Question 19

How many micrograms are in 1 mg?

Answer 19

1,000

Question 20

A cough syrup contains 4 grams of brompheniramine maleate per liter. How many milligrams are contained in a teaspoon full dose of the elixir?

Answer 20

First convert grams to milligrams

4 g x 1000mg / 1g = 4,000 mg per 1 liter

1tsp =5 mL

4,000mg/1,000mL = x mg/5 mL. X=20

Question 21

In elixir of Ferrous sulfate contains 220 mg the Ferrous sulfate for 5 mL. If each milligram the Ferrous sulfate contained the equivalent of 0.2 mg of elemental iron, how many milligrams of elemental iron would be in each 5 mg of elixir?

Answer 21

0.2 mg Fe/ 1 mg FeSO4 = xmg Fe/ 220 FeSO4. X= 44 mg of elemental Fe

Question 22

What percentage of elemental iron is contained in Ferrous sulfate (FeSO4)?

Answer 22

20%

Question 23

Sig: i-ii tabs PI q 4-6 hrs prn pain x 2 days. NTE 6/d

How many tablet should be dispensed?

Answer 23

12 tablets

Note NTE = not to exceed

Question 24

The pharmacist prescription for Vigamox .5%.
Dispense 3 mL. 1 gtt tid ou x 7d.

How many drops will the patient use per day?

Answer 24

Six drops

Note that the patient is using in both eyes and the questions only asking for one day

Question 25

A seven-year-old male child (3 feet, 4 inches and 48 pounds) presents to the urgent care clinic with a fever of 102°F, and nausea vomiting that begin the previous day. He will receive and acetaminophen five grain suppository for the fever. The pharmacist received a prescription for the suppository with the instructions: 1 PR Q4-6H pen temp >102 degrees. How many mg/kg willthe child receive per dose? Round to the nearest whole number.

Answer 25

One grain equal 65 mg 1gr/65mg = 5 gr/x mg. X =325mg 48 lb / 2.2 = 21.8 kg 325 mg/ 21.8kg = 15 mg/kg

Question 26

What is the recommended weight-based acetaminophen dosing for children under 12 years of age?

Answer 26

10 to 15 mg/ kg Q 4 to six hours

Question 27

What does the abbreviation ac mean?

Answer 27

Before a meal

Question 28

How many milliliters of Mylanta suspension or contained in each dose of the prescription below? Round to the nearest whole number Belladonna tincture 10ml Phenobarbital 60mL Mylanta susp. as. ad. 120mL Sig: 5 mL BID

Answer 28

The total prescription is 120 ML; 10 mL belladonna, 60 mL of phenobarbital, and that leaves 15 amount for the Mylanta. 50mL Mylanta/120 mL total RX = XML Mylanta/ 5 mL total RX dose. X = 2 mL Mylanta per dose

Question 29

A pharmacist will prepare and Amoxil suspension to provide 1600 mg daily dose for a child. The dues will be divided be BID. To prepare Amoxil containing 200 mg/5 ML the pharmacist should add 76 ML of water for a final volume of 100mL. The pharmacist accidentally added too much water in the final volume is 110 ML. How many ML should the patient take twice daily to receive the correct dose?

Answer 29

``` 200mg/5mL = xmg/100 mL X= 4,000mg ``` 4,000mg/110mL = 800mg/x mL X=22mL

Question 30

How many mg codeine will be contained in each capsule? ``` Codeine. 0.6g Guaifenesin. 1.2g Caffeine. 0.15g M. ft. Caps. No 24 Sig: one capsule TID PRN cough ```

Answer 30

Begin by converting to the units requested an answer (mg) 0.6g codeine x 1,000mg/1g = 600 mg codeine for the entire prescription The prescription order is for 24 capsules 600mg codeine total/24 caps = 25 mg codeine/ capsule

Question 31

Physician write an order for Aminophylline 500 mg IV, dosed at 0.5 mg per kilogram per hour for a patient weighing 165 pounds. There is only theophylline in stock. How many milligrams of theophylline will the patient received per hour? Round to the nearest whole number

Answer 31

Aminophylline to theophylline: multiply by 0.8 Theophylline to Aminophylline: divide by 0.8 Use dimensional analysis 0.5mg/1kg | 75kg/1hr = 37.5 mg/HR Aminophylline 37.5 mg/HR Aminophylline x 0.8 = 30 mg/HR theophylline

Question 32

How many grains aspirin will be contained in each capsule? Round to the nearest tenth ``` aspirin. 6g Phenacetin.3.2g Caffeine. 0.48g M. ft. No. 20 caps sig: One capsule Q6H PRN pain ```

Answer 32

65mg =1 grain ``` 6000mg/Xgrid = 65mg/1 gr X = 92.3 grains ``` 92.3 grains/20 capsules = 4.6 grains/capsule

Question 33

A metered dose inhaler provides 90 micrograms of albuterol sulfate with each inhalation. The canister provides 200 inhalations. If the patient uses the entire canister, how many total milligrams will the patient have received?

Answer 33

90mcg | xmg/1000 mcg = 0.09mg per inhalation 0.09mg/1 inhalation = x mg/ 200 inhalations Answer 18 mg

Question 34

What is the definition of percent weight in volume (% w/v)?

Answer 34

g/100 mL (A solid mixed into a liquid)

Question 35

What is the definition for percent volume in volume (% v/v)?

Answer 35

mL/100 mL (A liquid mixed into a liquid)

Question 36

What is the definition of percent weight in weight (%w/w)?

Answer 36

g/100g (A solid mixed into a solid)

Question 37

How many grams of NaCl are in 1 liter of normal saline (NS)?

Answer 37

``` Normal saline (NS) is 0.09% (w/v) NaCl solution. Remember w/v is always expressed as grams per 100 ML, therefore NS contains 0.9 g NaCl per 100mL of solution ``` 0.9g/100 mL = Xg /1,000 mL X=9g

Question 38

How many grams of NaCl are in 500mL of 1/2NS? Round to the nearest hundredth.

Answer 38

0.45g/100mL = xg/500mL. X= 2.25g

Question 39

How many grams of dextrose are in 250 mLs of D5W? Round to the nearest tenth.

Answer 39

D5 W refers to 5% (w/v) dextrose and water solution 5g/100mL = xg/250mL. X= 12.5g

Question 40

If 1250 g of a mixture contains 80 g of drug, what is the percentage strength (w/w) of the mixture? Round to the nearest tenth.

Answer 40

80g/1250g = Xg/ 100g X= 6.4g, which is 6.4%

Question 41

A mouth rinse contains 1/12% (w/v) of chlorhexidine gluconate. How many grams of chlorhexidine gluconate should be used to prepare 18 L of mouth rinse? Round to the nearest whole number.

Answer 41

1/12% = 0.083g per 100mL (w/v) 18L x 1,000mL/L = 18,000mL 0.083g / 100mL = xg/ 18,000 mL X= 14.94g, rounded to 15 g

Question 42

A pharmacist at 5.3 g of hydrocortisone to 150 g of a 2.5% hydrocortisone ointment. What is the percentage (w/w) of hydrocortisone in the finished product? Round to the nearest whole number.

Answer 42

First determine the amount of hydrocortisone in the current product. 2. 5g HC / 100g = xg HC/150g. X=3.75hc 5. 3 g of hydrocortisone is being added to the existing product which contains 3.75 g of hydrocortisone: 5.3g +3.75g =9.05g 9.05 g hc/ 155.3g ointment = xg hc/ 100g oint. X= 5.8274 g, rounded to 6%

Question 43

How many milliliters of a hydrocortisone liquid (40mg/mL) Will be needed to prepare 30 g of an 0.25% cream (w/w)? Rounded to the nearest hundredth.

Answer 43

First calculate the amount of Hydrocortisone needed in the final product 0.25g/100g = xg/30g X= 0.075 g or 75 mg Then solve for ML of Hydrocortisone liquid needed 40mg/ML = 75mg/xmL X= 1.875 mL, reindeer to 1.88mL