NAPLEX Question of the Week: Calculation Time!

A common question is the subject of our question of the week.
NAPLEX Question of the Week: Calculation Time!

AB is a 45 yo male presenting to your community pharmacy today to pick up some TrueMetrix glucose test strips. His past medical history includes type 2 diabetes mellitus, hyperlipidemia, and hypertension. He is currently taking metformin 1000 mg PO BID, Lipitor 40 mg PO daily, and Cozaar 25 mg PO daily.  You learn that he was recently diagnosed with diabetes 6 months ago, and he is still unsure what his hemoglobin A1C means. You explain to him that his A1C is his average blood glucose level over the past 2-3 months. Knowing that his A1C is 7.8% today, calculate his estimated average blood glucose in mg/dL. Round to the nearest whole number.

Answer with calculation: 163 mg/dL

The estimated average blood glucose level can be calculated from A1C using the following equation:

eAG=(28.7 X A1C)-46.7

Insert his current A1C into this equation to solve for eAG.

eAG=(28.7 X 7.8)-46.7

eAG=162.81 mg/dL

eAG=163 mg/dL

Hemoglobin A1C (referred to often as just A1C) represents the average blood glucose of a patient over the past 2-3 months. It is an important measure to determine if a patient’s current diabetes regimen is helping a patient obtain their goal blood sugar. The American Diabetes Association (ADA) currently recommends a general goal A1C of < 7% for most non- pregnant adults. This corresponds to their glucose goal levels as well, with 80-130 mg/dL when fasting. By keeping a patient’s glucose in range, this can reduce the patient’s risk of developing a number of microvascular complications including retinopathy, nephropathy, and neuropathy as well as macrovascular disease. Below is a quick reference table showing a patient’s A1C compared to their average glucose level.


A1C (%)

Glucose level (mg/dL)




















Naplex Competency Statements Covered

1.1 – Obtain, interpret, or assess data from instruments, screening tools, laboratory, genomic or genetic information, or diagnostic findings

4.1 – Perform calculations using patient parameters or laboratory measures


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Go to the profile of Annette
5 months ago

i worked this out and got 177.16.Please if you don't mind show how you got the answer. Thank you

Go to the profile of angel ng
19 days ago

I also got 177.16 and used a conversion calculator online and got very similar.