NAPLEX Question of the Week: Calculation Time!

A common question is the subject of our question of the week.

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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


Christopher M. Bland

Clinical Professor, University of Georgia College of Pharmacy

Dr. Christopher M. Bland is a Clinical Professor at the University of Georgia College of Pharmacy at the Southeast GA campus in Savannah, GA. Dr. Bland has over 20 years of academic and clinical experience in a number of clinical areas. He is a Fellow of both the Infectious Diseases Society of America as well as the American College of Clinical Pharmacy. He is co-founder of the Southeastern Research Group Endeavor, SERGE-45, with over 80 practitioners across 14 states involved. Dr. Bland serves as Associate Editor for the NAPLEX Review Guide 4th edition as well as Editor-In-Chief for the Question of the Week. He has provided live, interactive reviews for more than 10 Colleges/Schools of Pharmacy over the course of his career.