PTCB Order Entry 3/6

A patient is to take 1.5 g of amoxicillin prior to a dental appointment. The capsules available in the pharmacy are amoxicillin 500 mg.

What is the number of capsules that will be dispensed to the patient?

• 3

• 6

• 30

• 33

Answer explanation

First, convert the total amoxicillin needed from g to mg by moving the decimal point three places to the right or multiplying by 1000:

1.5 g x 1000 mg/g = 1500 mg total

Next, divide the total required by the strength per capsule to find the total number of capsules required:

1500 mg total ÷ 500 mg/capsule = 3 capsules

How many g of a drug are in 250 mL of a 40% solution?

• 4

• 10

• 40

• 100

Answer explanation

A 40% solution means that there are 40 g of drug in 100 mL of the solution. You need to calculate how much drug would be in 250 mL of the solution. This can be done by setting up a proportion.

(40 g/100 mL) = (x g/250 mL) x = 100 g

Which two items on a manufacturer's bottle are typically used to identify recalled drugs?

• DEA number and medication schedule

• NDC number and expiration date

• Lot number and expiration date

• NDC number and lot number

Answer explanation

A product's National Drug Code (NDC) number and lot number are often used to identify whether the product is subject to a recall. The NDC number indicates a product's manufacturer or labeler, specific dosage form and strength, and package size, while the lot number indicates the manufacturing history of a particular batch of medication. The information provided in Options (A), (B), and (C) is typically not enough to identify the specific recalled product.

On 3/15/2025 a pharmacist asks a pharmacy technician to remove any medications from the pharmacy's shelves that have an expiration date fewer than 90 days from 3/15/2025.

Which of the following products should be removed?

• A bottle of amoxicillin 250 mg chewable tablets expiring 5/26

• A refrigerated bottle of Humulin N expiring 12/25

• A bottle of warfarin sodium 10 mg tablets expiring 6/25

• A bottle of digoxin 0.125 mg expiring 5/25

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; in this case, the expiration date is 5/31/2025, which is less than 90 days from 3/15/2025. Option (A) expires on 5/31/2026, Option (B) expires on 12/31/2025, and Option (C) expires on 6/30/2025.

Indomethacin liquid must be compounded according to the following prescription:

Indomethacin 2 mg/mL Cherry syrup ad 100 mL

Sig: 5 mL PO b.i.d. Only 25 mg capsules of indomethacin are available.

How many capsules should be used to compound this prescription?

• 4

• 6

• 8

• 10

Answer explanation

In order to answer this question, you must first determine the total quantity to be made with the compound. The abbreviation "ad" means up to, so to make this compound you need to add cherry syrup up to 100 mL, which means the total amount of liquid should equal 100 mL. The directions (5 mL PO b.i.d.) are extra information that is not needed to answer the question. Next, you need to determine how much indomethacin is needed for the 100 mL. This can be determined using the concentration of the compound, which is 2 mg/mL.

(2 mg/mL)(100 mL) = 200 mg

Next, since you have 25 mg indomethacin capsules available to you, you need to determine how many capsules it would take to get 200 mg of indomethacin. This can be done by using division.

200 mg ÷ 25 mg/capsule = 8 capsules

A pharmacy technician is asked to double check the mathematical calculations for preparing 2.5 L of a solution of 25% urea in sterile water for irrigation.

The technician verifies that the amount of urea needed, in g, is:

• 50.5

• 62.5

• 500

• 625

Answer explanation

A 25% urea solution means that there are 25 g of urea per 100 mL of solution. You need to calculate how many g of urea are needed for 2.5 L of solution. You can do this by setting up a proportion, but first you need to convert 2.5 L to mL in order to match up units using the conversion of 1 L = 1000 mL. This can be done by setting up a proportion or moving the decimal place three places to the right.

(1 L/1000 mL) = (2.5 L/x mL) x = 2500 mL

Now, you can set up your final proportion to determine how much urea is in 2500 mL of solution.

(25 g/100 mL) = (x g/2500 mL) x = 625 g

A patient presents the following prescription:

Humulin insulin U-100 Qty 10 mL vial

Inject 20 units subcutaneously in the morning and 30 units subcutaneously in the evening.

How many vials should be dispensed for a 30-day supply?

• 1

• 2

• 3

• 4

Answer explanation

In order to solve this problem, you need to understand that U-100 insulin means that there are 100 units of insulin in 1 mL. The patient is taking 20 units of insulin in the morning and 30 units of insulin in the evening, so they are taking 50 total units per day (20 units + 30 units = 50 units). Since the problem is asking how many vials you need for a 30 days supply, you first need to determine how many units the patient needs for 30 days. This can be done using multiplication (50 units/day × 30 days = 1500 units). Finally, since 10 mL vials are available, calculate how many to dispense. There are 100 units of insulin in 1 mL, so in 10 mL there are 1000 units of insulin (100 units/mL × 10 mL/vial = 1000 units/vial). If 1500 units are needed for 30 days, determine how many vials are needed using division.

1500 units ÷ 1000 units/vial = 1.5 vials (round up to 2 vials, since if you only dispensed one you would not provide enough for 30 days)

The physician gives the following order for a prescription:

Cefaclor 250 mg/5mL 1 tsp PO t.i.d. for 10 days.

What is the amount, in mL, needed to fill the order?

• 100

• 150

• 250

• 450

Answer explanation

In order to solve this problem, you need to understand the abbreviations. The abbreviation “tsp” means teaspoon and “t.i.d.” means 3 times a day. The patient is to take 1 teaspoon 3 times per day for 10 days. Next, you need to understand conversions. Since the problem wants to know how many mL the patient will need, you need to convert tsp to mL using the conversion of 1 tsp = 5 mL. The patient is taking 5 mL 3 times per day for 10 days, so you can determine how many mL are needed in a day by using multiplication. The drug concentration is extra information that is not needed to solve this problem.

5 mL/dose × 3 doses/day × 10 days = 150 mL

A particular manufacturer packages amlodipine 2.5 mg tablets with an NDC of 00603-2108-02. If a pharmacy technician wants to receive hydrochlorothiazide 12.5 mg capsules from the same manufacturer, which of the following NDCs should they order?

• 16590-580-90

• 42543-710-02

• 0527-2108-10

• 0603-3855-21

Answer explanation

The first segment of a National Drug Code (NDC) number, also known as the labeler code, is assigned by the Food and Drug Administration (FDA). A labeler is any firm that manufactures (including repackers or relabelers) or distributes (under its own name) a drug. The middle segment, also known as the product code, identifies a specific strength, dosage form, and formulation of a drug for a particular manufacturer or labeler. The third segment, also known as the package code, identifies package sizes and types. In this scenario, the products' first segments must match to ensure that the medications are from the same manufacturer.

The formula for an ointment calls for

10 parts coal tar, 15 parts zinc oxide, and 40 parts hydrophilic ointment.

How much of each ingredient would be required for a 1000 g prescription?

• 87 g coal tar, 134 g zinc oxide, 667 g hydrophilic ointment

• 113 g coal tar, 255 g zinc oxide, 734 g hydrophilic ointment

• 145 g coal tar, 225 g zinc oxide, 680 g hydrophilic ointment

• 154 g coal tar, 231 g zinc oxide, 615 g hydrophilic ointment

Answer explanation

In order to solve this problem, you need to understand what is meant by "parts." Since there are 10 parts coal tar, 15 parts zinc oxide, and 40 parts hydrophilic ointment, that means there are 65 total parts in the 1000 g preparation (10 parts + 15 parts + 40 parts = 65 parts). Using percent rules, you can determine the percentage of each ingredient in the preparation and then multiply by the total weight (1000 g). Coal tar takes up 10 of the 65 parts or 15.4% (10 ÷ 65 × 100% = 15.4%), zinc oxide takes up 15 of the 65 parts or 23.1% (15 ÷ 65 × 100% = 23.1%), and hydrophilic ointment takes up 40 of the 65 parts or 61.5% (40 ÷ 65 × 100% = 61.5%). You can do a quick double check to ensure all of the parts are equal to 100% (15.4% coal tar + 23.1% zinc oxide + 61.5% hydrophilic ointment = 100%). You can now use those percentages to determine the weight of each ingredient needed in g. This is most easily done by converting the percentage to a decimal by moving the decimal point two places to the left and then multiplying by the total weight.

(0.154 × 1000 g) = 154 g coal tar
(0.231 × 1000 g) = 231 g zinc oxide
(0.615 × 1000 g) = 615 g hydrophilic ointment

You can solve this in an alternative way using proportions. You already established above that there are 65 total parts, so there would be 65 total parts in 1000 g in this scenario. You then can determine how many g are needed for 10, 15, and 40 parts.

(65 parts/1000 g) = (10 parts/x g) x = 154 g coal tar
(65 parts/1000 g) = (15 parts/x g) x = 231 g zinc oxide
(65 parts/1000 g) = (40 parts/x g) x = 615 g hydrophilic ointment

You can also add all of the quantities up to ensure that they equal 1000 g to double check your work (154 g coal tar + 231 g zinc oxide + 615 g hydrophilic ointment = 1000 g).