Which detail is included in the calculation of a DEA number check digit?

• A. The sum of all even positions only
• B. The sum of odd positions divided by ten
• C. The last digit of the total sum of specific positions
• D. The product of all digits

Answer: (C)

The correct detail included in the calculation of a DEA number check digit is the last digit of the total sum of specific positions. The process for calculating the check digit of a DEA number involves assigning weights to the digits in specific positions: odd positions and even positions.

First, the digits in the odd positions are summed, and this sum is multiplied by 1. The even-positioned digits are summed, and this sum is multiplied by 2. The total of these calculations is obtained, and then you take the last digit of this total to determine the check digit. This is a crucial step in ensuring the authenticity and validity of the DEA number, as it helps detect errors in transcription or forgery.

The final aspect of the total sum—taking the last digit—is key to establishing whether the DEA number adheres to the algorithm, thus reflecting compliance with regulations and secure handling of controlled substances. The accuracy of this check is vital for pharmacy practice and the overall safety of medication distribution.