PTCB Order Entry 6/6

What volume, in mL, of 125 mg/5 mL amoxicillin suspension should be prepared to deliver a prescribed dose of 375 mg?

• 3

• 15

• 25

• 75

Answer explanation

In order to solve this problem, you need to determine how many mL of a 125 mg/5 mL amoxicillin suspension will give a patient 375 mg of amoxicillin. This can be done by setting up a proportion.

(125 mg/5 mL) = (375 mg/x mL) x = 15 mL

USP Chapter 795 requires that compounded capsules should not be less than 90% and no more than 110% of the theoretically calculated weight.

If the calculated weight of a compounded capsule is 200 mg, all capsules in the batch should weigh:

• more than 220 mg.

• between 190 mg and 210 mg.

• between 180 mg and 220 mg.

• less than 180 mg.

Answer explanation

Since the capsules need to be between 90%-110% of their theoretically calculated weight, you would expect to obtain a range for your answer. You start by converting both percentages to a decimal by moving the decimal point 2 places to the left, and you get 0.9 and 1.1. You can then take those numbers and multiply by the quantity that you are compounding which is 200 mg. This will give you the quantity that is within 90% and 110%.

200 mg × 0.9 = 180 mg
200 mg × 1.1 = 220 mg

How many 0.75 mg tablets are needed to administer a 6 mg dose daily for 4 days?

• 6

• 14

• 16

• 32

Answer explanation

In order to solve this problem, first determine how many mg the patient will take over 4 days. This can be done by multiplication, since they will take 6 mg/day (6 mg/day × 4 days = 24 mg). Next, determine how many tablets you would need to dispense in order to provide the patient 24 mg when you have 0.75 mg tablets available. This can be done using division.

24 mg ÷ 0.75 mg/tablet = 32 tablets

A physician orders phenobarbital elixir 60 mg for a patient. The drug is available in a 20 mg/5 mL concentration. How many tsp should be given for each dose?

• 1

• 2

• 3

• 4

Answer explanation

First, find how many mL of elixir are required for a dose of 60 mg.

20 mg/5 mL = 4 mg/mL
60 mg ÷ 4 mg/mL = 15 mL

Then, convert mL to tsp. 1 tsp is equivalent to 5 mL.

15 mL/5 mL per tsp = 3 tsp

A patient is taking a medication prescribed by a physician at a dosing schedule of 2 tablets every 4 hours. If the patient is receiving 240 tablets at each fill, for how many days will the prescription supply last?

• 20

• 30

• 40

• 60

Answer explanation

The first step to answering this question is to calculate how many tablets the patient should take in one day. Since there are 24 hours in 1 day and the patient can take 2 tablets every 4 hours, they can take 2 tablets 6 times per day (24 hours ÷ 4 hours/dose = 6 doses). Next, since the patient can take 2 tablets 6 times per day, they can take 12 tablets total in 1 day (2 tablets/dose × 6 doses/day = 12 tablets/day). Finally, if the patient receives 240 tablets total, you can calculate how long the prescription will last the patient if they use 12 tablets per day using division.

240 tablets ÷ 12 tablets/day = 20 days

An expiration date of 7/2025 on a vial of mumps virus live vaccine means that the vial contents expire:

• on 6/30 of 2025.

• on 7/1 of 2025.

• on 7/31 of 2025.

• 6 months past this date.

Answer explanation

If an expiration date is stated only in terms of the month and the year, the intended expiration date is the last day of the stated month.

If a compound prescription calls for 360 mL of baclofen 2 mg/mL, how many 10 mg tablets are needed to fill the prescription?

• 18

• 20

• 36

• 72

Answer explanation

First, you need to determine how much baclofen is needed to make a 360 mL compound. This can be determined using the concentration of the compound, which is 2 mg/mL.

(2 mg/mL)(360 mL) = 720 mg

Next, since you have 10 mg baclofen tablets available to you, you need to determine how many tablets it would take to give you 720 mg of baclofen. This can be done using division.

720 mg ÷ 10 mg/tablet = 72 tablets

A pharmacy technician compounding which of the following may adhere to the standards of USP Chapter 795 only?

• A batch of 15 bottles of nonhazardous ear drops

• An eye drop bottle for a specific patient

• Three bags of parenteral nutrition

• A hazardous oral suspension from capsules

Answer explanation

USP Chapter 795 provides guidelines for compounding non-hazardous, non-sterile preparations only.

The pharmacy stocks a 300 mL bottle of 7.5% solution. If the dose of the solution is 1 tsp, what is the drug dose?

• 0.375 mg

• 22.5 mg

• 0.375 g

• 22.5 g

Answer explanation

If you have a 7.5% solution, that means that there are 7.5 g of drug in 100 mL of the solution. The dose of the product is 1 tsp which is equal to 5 mL. A proportion can be set up from there to find out how many g of drug is in 5 mL, and by solving for x you will find your answer.

(7.5 g/100 mL) = (x g/5 mL) x = 0.375 g

A patient presents the following prescription:

Methylphenidate 10 mg 1.5 tablets at lunch time on weekdays 1 tablet every morning on weekends. Dispense a 4 week supply.

How many methylphenidate 10 mg tablets are required to fill this prescription?

• 38

• 42

• 44

• 48

Answer explanation

The first step to answer this question is to determine how many tablets are required each week. With 1.5 tablets used each weekday and 1 tablet used each weekend day, one week would require:

1.5 tablets/day x 5 weekdays = 7.5 tablets
1 tablet/day x 2 weekend days = 2 tablets

Therefore, each week requires 9.5 tablets (7.5 + 2). You can then multiply that by 4 as the question asks for the number of tablets required to cover a 4 week supply: